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SH--3076-1996

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SH--3076-1996 Powered By Docstoc
					UDC                                                                  SH
               STANDARDS FOR INDUSTRIES OF
             THE PEOPLE’S REPUBLIC OF CHINA

 P                                                          SH 3076―96



   CODE FOR DESIGN OF BUILDING STRUCTURES
             OF PETROCHEMICAL ENTERPRISES

                           (石油化工企业建筑物结构设计规范)




Issued on 1996 - 03 – 14                        Implemented as of 1996 –09 - 01

             Issued by China National Petrochemical Corporation
                                                           CONTENTS

1.General Provisions ............................................................................................................. 1
2. Load .................................................................................................................................... 1
   2.1 General Regulations ................................................................................................... 1
   2.2 Dynamic Load ............................................................................................................ 3
   2.3 Indirect Action on Structure ....................................................................................... 3
3. Base and Foundation ......................................................................................................... 4
   3.1 General Regulations ................................................................................................... 4
   3.2 Selection of Foundation Types ................................................................................... 5
   3.3 Calculation of Base and Foundation .......................................................................... 6
    3.4 Structure of Foundation ............................................................................................ 12
4. Selection of Structure Types.............................................................................................. 15
5. Reinforced Concrete Single-Story Building .................................................................. 16
    5.1 General Regulations ................................................................................................. 16
    5.2 Main Points for Calculation ..................................................................................... 17
    5.3 Column ..................................................................................................................... 22
    5.4 Bracing System ......................................................................................................... 23
    5.5 Roof Structure .......................................................................................................... 27
    5.6 Lifting Beam............................................................................................................. 27
    5.7 Building Enclosure and Others................................................................................. 28
6. Reinforced Concrete Multiple-story Factory Building ................................................ 29
   6.1 General Regulations ................................................................................................. 29
   6.2 Analysis of Frame Internal Force ............................................................................. 30
7 Buildings of Brick-Concrete Structures ......................................................................... 33
   7.1 General Regulation ................................................................................................... 33
   7.2 Rules for Calculations .............................................................................................. 34
   7.3 Structural Requirements ........................................................................................... 36
8. Semi-Underground Pumphouse ..................................................................................... 40
   8.1 General Regulations ................................................................................................. 40
   8.2 Rules for Calculation ................................................................................................ 40
   8.3 Structural Requirements ........................................................................................... 41
Annex A Value of Dynamic Coefficient  ......................................................................... 43
Annex B Common Column Section Dimensions .............................................................. 45
Annex C Notes of Wording for the Standard ................................................................... 46
1.General Provisions
1.0.1 This code is applicable to structural design of new building of petrochemical enterprises and the
rebuilt and expanded projects may be handled with reference to this code.
1.0.2 The structure of a building shall be designed in accordance with the limiting conditions of bearing
capacity and those of normal application.
1.0.3 The structural design of a building shall meet the requirements of resistance to earthquake, fire,
explosion and corrosion.
1.0.4 The arrangement, type selection and structural treatment of the building structure shall take into
consideration the requirements of technological production, installation and maintenance.
1.0.5 The structure plan shall be characterized by definite force bearing, simple and quick transmission of
force and good integrity.
1.0.6 The structural design should be carried out in accordance with the unified modulus. The component
parts used in a same project shall be of the same type.
1.0.7 The effective new technology, new structure and new material shall be adopted and popularized in
an active way. The local material and industrial waste shall be rationally utilized.
1.0.8 The implementation of this code shall comply with the requirements of the related standards and
codes in force.



2.   Load


2.1 General Regulations
2.1.1 The classification of load, floor and roof load shall comply with the regulations of the present
national standard 《Code for Load of Building Structure》 in addition to those of this chapter. Moreover,
the action of earthquake shall comply with the regulations of the present national standard 《Code for
Seismic Design of Building 》.

2.1.2 The live load for operation of the floor of production building (including the weights of operating
personnel, ordinary tools, fragmentary raw material and finished products) may be considered as uniformly
distributed live load, of which the standard value shall not be less than 2.0 kN/m2.
2.1.3 The local load on the floor of production building during production, operation, maintenance,
construction and installation and load of suspended piping shall be adopted according to the actual
conditions, taking into consideration its adverse influence on beam and slab and may be replaced by
equivalent and uniformly distributed load.
2.1.4 The standard value of minimum live load on the walkway and platform may be adopted according
to the following regulations:
(1) Walkway and walkway platform 2.0 kN/m2;
(2) Tower and vessel platform        3.0kN/m2;
                                                    1
(3) Operating area or operating platform 4.0 kN/m2;
(4) Staircase and rest platform of the production building 4.0 kN/m2;
(5) Area where parts or heavy tools may be stored around the heat exchanger or similar equipment 4.0
kN/m2;
2.1.5 4.0 kN/m2 may be adopted as the standard value of uniformly distributed live load on the floor of
control room.
2.1.6 5.5 ~7.5 kN/m2 may be adopted as the standard value of live load on the floor of low-voltage
distribution room and 8.0 ~10.0 kN/m2 may be adopted as that of uniformly distributed live load on the
floor of high-voltage distribution room.
2.1.7 2.0 kN/m2 may be adopted as the standard value of live load on the floor of workshop living room,
office and laboratory. The standard value of live load on the floor of laboratory may be determined
according to the actual conditions, but shall not be less than 2.0 kN/m2.
2.1.8 The standard value of live load on the floor maintenance area of compressor and main fan rooms
and power station shall be adopted according to the actual conditions, but shall not be less than 10.0 kN/m2.
2.1.9 The live load on the floor of warehouse shall be adopted according to the actual conditions.
2.1.10 2.5 kN/m2 shall be adopted as the standard value of live load on the belt loading bridge for
calculating the floor and secondary beam, while 2.0 kN/m2 is adopted for calculating the main beam and
support.
2.1.11 Apart from being determined according to the actual conditions, the standard value of live load on
the floor of multiple-story production building shall comply with the following regulations:
2.1.11.1 Generally for the factory building with small equipment (which is less than 200kN in weight),
the standard value shall not be less than 4.0 kN/m2;
2.1.11.2 For the factory building with reactor, width stretcher, evaporator, spinning machine or material
storage, the standard value shall not be less than 6.0 kN/m2;
2.1.11.3 For the factory building with centrifugal machine (which shall have vibration damper), the
standard value shall not be less than 5.0 kN/m2;
2.1.12 The reduction of live load on multi-layer frame building shall comply with the following
regulations:
2.1.12.1 In calculating slab and secondary beam, the load shall not be reduced;
2.1.12.2 In calculating primary beam and frame foundation, if their load area exceeds 25 m2, generally the
following reduction coefficient may be adopted:
(1)   0.7 for the live load on floor of less than or equal to 10 kN/m2;
(2)   0.5 for the live load on floor of greater than 10 kN/m2;
(3) The reduction coefficient of the live load on floor of multiple-story warehouse shall not be less than
0.85 (or determined according to the actual conditions).



                                                       2
2.1.13 For designing the platform railing, the standard value of horizontal thrust shall be 1.0 kN/m2
which acts on the top of railing.
2.1.14     The load of pile-up material and equipment for production on ground and load of land transport
shall be determined according to the actual conditions.
2.1.15     In considering the dust load on roof, attention shall be paid to the influence of the adjacent area
(including nearby factory) on the dust load of this building.


2.2 Dynamic Load
2.2.1 The power equipment (such as centrifugal machine, crusher, vibrating screen, extruder, reactor,
evaporator, spinning machine, large-size ventilator and so on) installed on the floor should have vibration
isolator. The dynamic load parameters of different kinds of power equipment shall be supplied by the
manufacturer.
2.2.2 The dynamic load of structure shall be calculated and determined according to the special
regulations. A part of the power equipment may be statically calculated by multiplying the weight of
equipment by dynamic coefficient which is listed in Appendix A. With reliable experience, a part of power
equipment may be calculated according to the experienced method.
The stationary equipment with driving device may be calculated by multiplying the weight of rotating part
by dynamic coefficient.
After taking appropriate measure for vibration isolation, the dynamic load of the following equipment may
not be taken into consideration (except for steel platform).
(1) Ordinary equipment of which the motor power is not greater than 100 kW;
(2) Crusher, vibrating screen and other equipment of which the motor power is not greater than 75 kW;
(3) Forced draught fan of which the type is smaller than no. 10.
2.2.3 Generally the dynamic coefficient for transporting, loading and unloading heavy weight may be
adopted according to 1.1 ~ 1.2, only taking into consideration its dynamic action transmitted to the floor
and beam.


2.3   Indirect Action on Structure
2.3.1 Action of temperature
2.3.1.1 For the equipment, vessel, reactor and piping in the process of production, the expansion,
contraction and action of the component parts on structure due to the change of temperature shall be taken
into consideration;
2.3.1.2 For the equipment subject to the influence of temperature in the process of production, the
horizontal action of the change of temperature on the top of foundation shall be taken into consideration
and calculated according to the following formula:
                          Ftk = μGBK                               (2.3.1)


                                                      3
Where      Ftk—standard value of horizontal action on the supporting top;
          μ—Friction coefficient between supporting base plate and supporting surface of the equipment,
            which is 0.45 for concrete supporting surface and 0.3 for sheet steel supporting surface;
          GBK—Standard value of equipment permanent load acting on this support under normal operating
              condition.
2.3.2 Coring load of heat exchanger
The foundation of heat exchanger shall take into consideration the horizontal load caused by coring during
maintenance. This load acts on the axis of heat exchanger. If several heat exchangers are placed one on
another, only the topmost one is calculated. The horizontal load caused by coring shall be calculated
according to the following formula.
                          Fbk = Gbk                              (2.3.2)
Where Fbk— standard value of coring force;
        Gbk— standard value measured by the bundle of cold-water exchange equipment.



3.   Base and Foundation


3.1 General Regulations
3.1.1 The base and foundation shall be designed by adhering to the principles of suiting measures to local
conditions and using local materials, according to the geological prospecting data and taking into
consideration in a comprehensive way the body type of building, type of structure, load condition, existence
or nonexistence of basement, foundation of adjacent building, position and elevation of underground
structure and different facilities, conditions for construction, requirement for use, project cost and other
factors.
3.1.2 The design of base and foundation of soft soil, wet and depressed loess, expanded soil and under
the action of earthquake and mechanical dynamic load shall comply with the regulations of related standard
and code in force.
3.1.3 All pits, caves, graves, wells and so forth within the range of influence of the building foundation
shall be disposed.
3.1.4 In water-proof design, the elevation of water level of the building basement may be determined
according to the following principles:
3.1.4.1 For the basement with important electromechanical equipment which, in case of flooding, will
exert great influence on the normal use of the building or cause heavy losses to it, the water-proof design
shall be conducted according to the highest water level over the years in that area (the elevation of water
level shall include the stagnant water on the upper floor);
3.1.4.2 For the basement used as ordinary air-raid shelter, garage or warehouse which will not have great
influence in case of flooding, the elevation of its groundwater level may take the average value of the
highest water level over the years and the highest water level in recent 3 to 5 years (the elevation of

                                                     4
water level shall include the stagnant water on the upper floor).
3.1.4.3 In checking the bearing capacity of outer wall of the basement, the highest water level in recent 3
to 5 years may be taken as the elevation of water level, not including the stagnant water on the upper floor.


3.2     Selection of Foundation Types
3.2.1 For the base and foundation of a building, natural base should generally be adopted. If the natural
base cannot meet the requirements of design or is uneconomical, artificial base may be adopted.
3.2.2 The type selection of foundation with masonry structure shall comply with the following principles:
3.2.2.1 Rigid foundation should be used as the wall column foundation. If the base is soft and uneven
with a small bearing capacity and a foundation width of more than 2.0 m, flexible foundation with
reinforced concrete under the wall should be adopted;
3.2.2.2 When the bearing wall foundation is no more than 1.8 m in depth, flexible strip foundation should
be adopted. When it is 1.9 ~ 2.4 m in depth, flexible strip foundation or pier foundation and foundation
beam may be adopted. When it is more than 2.4 m in depth with solid base, pier foundation and foundation
beam should be adopted;
3.2.2.3 When the non-bearing wall is no more than 240 mm in thickness and no more than 4.0 m in
height, the ground pad layer may be thickened without laying additional foundation.
3.2.3 If the framed structure has no basement and the standard value of the base bearing capacity is
greater than 130 kPa and even, priority should be given to single column foundation. When the standard
value of the base bearing capacity is less than 130 kPa with small column space, heavy load or excessive
difference between column loads which may cause great relative settlement or great change in
compressibility of the main compressed layer of foundation and the adoption of single column foundation
cannot meet the requirement of design, strip foundation with reinforced concrete under the column may be
adopted.
When part of the column foundation of a building is more than 3.0 m in depth, short column foundation
should be adopted. If it is no more than 3.0 m in depth or individual foundation is a bit deep, the foundation
pad layer may be thickened.
3.2.4 When the load of a building with framed structure is heavy and the base is soft and uneven,
crosswise reinforced concrete strip foundation may be used.
When this crosswise foundation still cannot meet the requirements of design or the basement used as
air-raid shelter has water-proof requirement, raft reinforced concrete foundation or box foundation may be
used.
3.2.5 In the following cases, pile foundation may be used:
3.2.5.1 When the base is uneven or base on bearing stratum is soft and has better low-lying stratum and
the adoption of raft foundation is uneconomical;
3.2.5.2 For the important building which has special requirement for base in application and production
technology or has great pressure on bottom of foundation, when the settlement estimated by natural base
exceeds the allowable value;
                                                      5
3.2.5.3 For the high-rise building, if the construction conditions do not allow to use deeply-embedded
natural base or it is not evidently economical;
3.2.5.4 When the additional stress of base between units of the building interacts on each other, causing
excessive uneven settlement;
3.2.5.5 When the use of pile foundation is economical because of a vast area of stacked material or thin
layer of soft soil under the foundation.


3.3      Calculation of Base and Foundation
3.3.1 When the bottom area of column foundation of a factory building is determined on the basis of the
base bearing capacity, the design value of pressure on the foundation base shall be taken according to the
following regulations:
3.3.1.1 For the column foundation of a factory building with a load of crane (not including crane for
maintenance), the design value of pressure on the foundation base shall not be negative (see Fig. 3.3.1—1)
and shall meet the requirements of the following formula:
                    e < B/6                                  (3.3.1—1)
                    e = M/ (N + G)                           (3.3.1—2)
where e — eccentric load (m);
       M — bending moment acting on centroid of foundation base (kN·m);
       N — vertical load acting on centroid of foundation top (kN);
       G — dead weight of foundation and soil (kN);
       B — foundation width (m).

When bearing load of electric bridge crane and the design value of bearing capacity of foundation f < 170
kPa, the profile of pressure on the foundation base shall assume trapezoid and Pmin/Pmax > 0.25.
3.3.1.2 For the column foundation of a factory building with a crane for maintenance but without load of
crane, when the wind load combination is taken into consideration, the design value of the pressure on
foundation base is allowed to be negative (see Fig. 3.3.1.2) and shall meet the requirements of the
following formula:
                    e < B/4                             (3.3.1—3)




                              When e < B/6                     When e = B/6
                    Fig. 3.3.1—1 Pressure on column foundation base with crane

                                                    6
                                                   When B/6 < e < B/4
                    Fig. 3.3.1—2 Pressure on column foundation base without crane

3.3.2 The bilaterally and eccentrically-loaded column foundation shall be calculated according to the
following regulations:
3.3.2.1 The bilaterally and eccentrically-loaded column foundation, when meeting the following formula,
may be calculated according to the unilaterally and eccentrically loaded one:
                    ey /A ≤ 0.2 ex / B                           (3.3.2—1)
where A — short-edge width of foundation base (m);
        B — long-edge width of foundation base (m);
  ex and ey— eccentric value of foundation base axial force at long and short sides (m).
3.3.2.2 When ey ≤ A/6 and ex ≤ B/6, the pressure on foundation base shall take into consideration the
influence of bending moments at the directions of X and Y. The bending moment at the cross section of
column edge may be approximately calculated according to formulas (3.3.2—2 and 3):

                  ( B  b) 2 ( 2 A  a )
             MI                         PI                    (3.3.2  2)
                           24


                    ( A  a ) 2 ( 2 B  b)
           M II                             PII               (3.3.2  3)
                              24
where a and b—sizes of short and long edges of the column respectively;
      P1 and PII— maximum pressure on the calculated foundation edges.

                     N     6M x
             PI         
                    B  A AB 2

                   N   6M y
          PII         2
                  B A A B

                                                           7
        Fig.3.3.2—1 External force calculated on the foundation with bilateral eccentricity

3.3.2.3 When the foundation partially leaves the soil, the design value of foundation base pressure may be
calculated according to the following formula:
                              N G
              Pm ax  0.35                       (3.3.2  4)
                             C X  CY

where Cx and Cy— distances from acting point of vertical load to the

                   nearest edges of foundation at X and Y coordinates,
                   Cx·Cy ≥ 0.125 B·A.




         Fig.3.3.2—2 Schematic diagram of bilaterally and eccentrically- loaded positions

3.3.3 The calculation of short-column cup-shaped foundation shall comply with the following regulations:
3.3.3.1 When the height Hs of upper step of foundation is greater than Hc+ t + 125 (mm), then it is
deemed as the short-column cup-shaped foundation (see Fig. 3.3.3—1);

3.3.3.2 When the short-column cup-shaped foundation complies with the following formula, its influence
on the bent may be neglected (see Fig. 3.3.3—2);
                                                    8
                         Δ1 / Δ2 < 1.1                        (3.3.3)

Where:
Δ1—column cap deflection caused when force is concentrated on the column cap action unit with the
foundation top (or short column base) as a fixed end:
Δ2—column cap deflection caused when force is concentrated on the column cap action unit with the cup
mouth top as a fixed end.




              Fig.3.3.3—1 Schematic diagram of short-column cup-shaped foundation




                                                         Cup mouth top
                                              Short column bottom


               Fig.3.3.3—2 Analysis of influence of short column foundation on bent

3.3.4 The base reaction of reinforced concrete strip foundation under the column should be calculated
with the solution of elastic foundation beam. When the foundation is of great plasticity and not too thick
soil layer, the foundation bed coefficient method should be adopted. For the reference value of foundation
bed coefficient see Table 3.3.4. When the foundation mainly lies on a thick compressed soil layer in a state
of elastic deformation, the semi-infinite elastomer method should be adopted. When the foundation beam is
higher than or equal to 1/6 of column space, it is assumed that the base reaction is distributed linearly.


                                                     9
                           Table 3.3.4 Reference value of foundation bed coefficient K

  Name of soil                                   State of soil            K (kN/m3)

 Weak sludge soil, organic of soil                                    0.51041.0104

        Clay, silty clay                       Soft plastic           0.51042.0104

                                               Plastic                2.01044.0104

                                               Hard plastic           4.010410.0104

        Sandy soil                             Loose                  0.71041.5104

                                               Medium density         1.51042.5104

                                               Density                2.51044.0104

        Gravelly soil                          Medium density         3.51044.0104

      Loess, loess silty clay                                         4.01045.0104

3.3.5 Upstanding beam method is suitable for foundation beam with a ratio of rise to span of 1/4 ~ 1/6,
even ground and no significant differential deformation. The internal force of beam may be calculated
according to the following method:
3.3.5.1 According to the calculating method of multiple-span continuous beam:
(1)       The base reaction may be assumed to distribute in straight line (take a unit width b =1);

                           N 6M
                   P          2                  (3.3.5  1)
                            L   L
where ΣN — resultant force of vertical loads (kN);
            L — length of foundation beam (m);
         ΣM — sum of vertical loads and their eccentric moment to the

                     moment at mid-point of foundation.
(2) For analysis of foundation beam internal force, the evaluated base reaction may be taken as the
external load and the column footing as the support of upstanding continuous beam. When the calculated
result cannot meet the static balance condition at the support, the unbalanced force may be used to adjust
the reaction, i. e. the unbalanced force is evenly distributed at both sides of the support within the range of
1/3 of the span to form a new stepped reaction distribution, calculate the adjusted internal force, again
calculate the superimposition of results. Repeat the above procedures until the support reaction and
unbalanced force of corresponding column load do not exceed 20 % of the load.
3.3.5.2 Empirical bending moment coefficient method
When the rigidity of superstructure and foundation is small and the ground is soft, the empirical bending
moment coefficient method may be adopted, taking into consideration the additional bending moment
caused by deformation and the calculation shall be conducted according to the following formula:


                                                         10
Bending moment of support:
                 Mm=( 1/10 1/14 )pl2          (3.3.5—2)

Bending moment at the middle of span:
                 Mms=( 1/10 1/16 )pl2         (3.3.5—3)
where p — evenly-distributed pressure at foundation base (kN/m);
         l — average value of calculated span between adjacent columns (m)

3.3.6 The internal force of cross strip foundation under the column may be reduced to calculate according
to the foundation beam, but when the torque in the foundation beam cannot be neglected any longer or is a
non-normal beam, it shall be calculated according to the finite element method of cross beam system of the
foundation.
For the cross reinforced concrete strip foundation, the column load on the intersection may be distributed
according to the ratio of linearity to rigidity of the strip foundation intersecting on this panel point or
according to the principle of equal deflection of strip foundation in the horizontal and longitudinal
directions at this panel point, then calculated respectively according to the strip foundation in the horizontal
and longitudinal directions.
3.3.7 The pressure on raft foundation base may be calculated with the short-cut calculating method. First
determine the pressure on the base in the direction of length of the raft foundation as that of elastic
foundation beam, then take some unit width in the direction of width of the foundation as elastic foundation
beam, its external force is the reaction calculated at all units in the direction of length, thus determining the
pressure on the base in the direction of width.
3.3.8 The range and method for calculating the building foundation deformation shall be handled
according to the regulations of the 《Code for Design of Building Base and Foundation》 in force.

3.3.9 For the calculation of building foundation under the action of ground load in a large area, not only
the foundation strength has to be checked, but also the foundation deformation has to be checked.
3.3.9.1 In calculating the building foundation deformation, the deformation caused by the building load and
the additional deformation caused by the ground load which does not directly act on the foundation shall be
taken into consideration.
3.3.9.2 The additional deformation of column foundation caused by the ground load shall be calculated
according to the Appendix 12 “Calculation of Foundation Additional Settlement under the Action of
Ground Load in a Large Area” to the 《Code for Design of Building Base and Foundation》 (GBJ 7―89).
But in some raw material and finished product warehouse of the chemical plant, the uneven load of the
stacked material in small grains which are liable to stack into a parabolic form or the stacked material load
often exceeds the design load, therefore it is necessary to cancel 0.8 from the formula in calculation.
3.3.10 In calculating the foundation deformation, the additional deformation caused by the adjacent
building or ground load shall be taken into consideration.
3.3.11 The net distance between the foundations of the adjacent buildings shall be determined according
to article 7.3.3 of the 《Code for Design of Building Base and Foundation》 (GBJ 7―89).


                                                       11
3.4    Structure of Foundation
3.4.1 The embedded depth of the foundation shall, apart from complying with the regulations in chapter 4
of the 《Code for Design of Building Base and Foundation》 (GBJ 7―89), meet the following
conditions:
3.4.1.1 The foundation top shall be less than 0.1 m below the outdoor design ground;
3.4.1.2 The foundation base of external wall or external column (except the rock foundation) shall be at
least 0.5 m lower than the outdoor design ground;
3.4.1.3 The foundation shall be embedded as shallow as possible with its base placed 0.15 m below the
surface layer of undisturbed aged soil.
3.4.2 Under the action of the corrosive medium, the corroded degree of the foundation decreases
gradually with the increase of depth from the ground. For the ordinary clayey soil base, the embedded depth
of the foundation should not be less than 1.0 m.
For the protection of the foundation, the following measures shall be taken respectively according to the
property of the corrosive medium, ground water level and importance of the building:
3.4.2.1 Properly increase the sectional size of the component part to leave a certain corrosion allowance;
3.4.2.2 The surface of the foundation (beam) is coated with bituminous cement or other anti-corrosive
paint;
3.4.2.3 Covered with a layer of clay which is good in water-resistant performance.
3.4.3 The applicable range and allowable value of the step aspect ratio of the rigid foundation shall
comply with the related regulations of the code for design of base and foundation in force of our country.
3.4.4 The structure and material of the rigid foundation shall comply with the following requirements:
3.4.4.1 Rubble foundation: The rubble shall not be less than MU 20, the cement mortar shall not be less
than M 5.0, the corbel width of each step shall not be more than 200 mm and the height of each step shall
not be less than 400 mm. The base width of strip foundation shall not be less than 500 mm, while the area
of independent column foundation shall not be less than 600 mm × 600 mm;

3.4.4.2 Brick foundation: The strength grade of brick shall not be less than MU 10.0, that of the cement
mortar shall not be less than M 5.0. The step is generally made by way of two-by-one or two-by-one
alternating with one-by-one bricklaying with 1/4 of a brick drawn in at a time.
3.4.4.3 Rubble concrete foundation: The strength grade of concrete shall not be lower than C 7.5 and that
of the frost-heaving ground should not be lower than C 10. The added quantity of rubble of MU 20 and
above with a grain size of less than 300 mm should not be more than 30% of the foundation volume the
height of each step shall not be less than 400 mm and the base width shall not be less than 400 mm;
3.4.4.4 Plain concrete foundation: The strength grade of concrete and foundation width shall be the same
as those of rubble concrete foundation with each step height of no less than 200 mm;
3.4.4.5 For the practice of the thickened ground underlayer, see Fig. 3.4.4.




                                                    12
          Fig. 3.4.4 Schematic diagram of the practice of the thickened ground underlayer
3.4.5 The reinforced concrete strip foundation under the wall shall comply with the following regulations:
3.4.5.1 The base plate of the strip foundation should not be less than 200 mm in thickness and its edge
should not be less than 150 mm in thickness. Beneath the base plate there should be underlayer which
should not be less than 70 mm in thickness.
3.4.5.2 The concrete strength grade of the strip foundation should not be less than C 20 and that of the
concrete underlayer may adopt C 7.5. For the stressed reinforcement, priority shall be given to the II-class
reinforcement of no less than 10 mm in diameter. For the distribution reinforcement, the I-class
reinforcement of no less than 8 mm in diameter shall be used with an area of no less than 10% of that of the
stressed reinforcement and a space of no more than 250 mm;
3.4.5.3 The reinforcement of the reinforced concrete strip foundation at the junction of T and cross and
corner may be arranged according to Fig. 3.4.5;
3.4.5.4 When the width of the reinforced concrete strip foundation is more than 2.5 m, the stressed
reinforcement may be reduced 10% in length, taking 0.9 time of the width B, and shall be placed in a
staggered way.
3.4.6 The structure of the strip foundation and raft foundation under the column shall comply with the
related regulations of the 《Code for Design of Building Base and Foundation》 in force of our country.

3.4.7 When there is change in the strip foundation embedment, it shall be laid in the form of staircase
with each step of no higher than 500 mm and no less than 1000 mm in length.
3.4.8 The base plane of the reinforced concrete single column foundation should be designed into
rectangle. When it is subjected to the eccentric load, the length-width ratio is no more than 2 generally and
no more than 3 in maximum. The base plane of the foundation which is subjected to axle load should adopt
a square.
The columnar axis of a single column foundation should coincide with the base surface. When it is
eccentric, check the effect of eccentricity.
3.4.9 When the piping passes through the foundation, a clearance of 100 ~ 200 mm shall be reserved
between the top of the reserved hole and the top of piping according the settlement of the foundation. When
the wall body below ±0.00 is much weakened by the through-wall pipe ditch, the adverse effect on the
structure shall be taken into consideration and the foundation wall shall be reinforced.
                                                     13
              The bidirectional main bars                         The main bars of horizontal
               overlap and distributing                            wall overlap and redouble
               bars are cancelled                                to the edge of longitudinal wall




                                             Narrow foundation


Space of main bars of
narrow foundation
redouble at the
overlapping place




Wide foundation




                Fig. 3.4.5 Reinforcement of the reinforced concrete strip foundation
                                            At corner, T and cross
3.4.10 At the settlement crack, due to the influence of foundation width, when it is necessary to use
reinforced concrete corbel beam at a side to support the upper masonry, the supporting length of the corbel
beam shall not be less than double of the corbel portion, the corbel portion should not have concentrated
load and the brick masonry on it should not have door and window openings. The space between the corbel
beam bottom and the foundation top at another end shall be determined through calculation, but shall not
be less than 200 mm ( see Fig. 3.4.10 ).




                          Fig. 3.4.10 Setting-up of foundation corbel beam

                                                     14
4. Selection of Structure Types
4.0.1 The selection of building structure types shall be analyzed and determined in a comprehensive way
according do the following conditions:
4.0.1.1 Production characteristics such as inflammability, explosion, corrosion, poisoning, vibration, high
temperature, low temperature, dust, moisture, more through-wall piping etc.;
4.0.1.2 Engineering geological condition, meteorological condition and seismic design intensity;
4.0.1.3 Span, height and column space of a building with or without crane and crane tonnage;
4.0.1.4 Construction technical condition and supply of material;
4.0.1.5 Technical and economic indicators.
4.0.2 The main production building (such as building for compressor, filter and molder of the production
equipment, power room, boiler room, air compressor room and air distributing room of the whole factory
system, packing and finished product storehouse), second-class building specified in the 《Standard for
Building Seismic Design Grade and Classification of Petrochemical Enterprises 》(SH 3049-93) and
heavy corrosive building should give priority to the reinforced cement structure.
4.0.3 When the adoption of reinforced cement structure is not rational or economical, the high building
and building with special requirement may adopt steel structure.
4.0.4 The factory building with high temperature may adopt steel structure or reinforced concrete
structure.
When the steel structure is adopted, if the surface of a component is subjected to radiant heat up to 100℃
and above for a long time or may be subjected to flame action within a short period of time, then effective
heat isolating or cooling measures have to be taken.
When the reinforced concrete structure is adopted, if the temperature on the surface of a component
exceeds 60℃, the heat influence has to be taken into consideration and heat isolating measure has to be
taken.
4.0.5 The single-story or multiple-story medium and small buildings may adopt brick-concrete structure
in case of the following conditions:
4.0.5.1 The closed single-story building without explosion-proof requirement, with span of no more than 12
m, column space of no more than 4 m and column height of no more than 7 m may adopt brick masonry
bearing structure;
4.0.5.2 The multiple-story building which complies with one of the following conditions should adopt
brick-concrete structure:
(1) The test building, office building and production accessory building of 5 stories and below supported
by dense transverse bearing walls or those of 4 stories and below supported by sparse transverse bearing
wall with the main beam span of all floors of no more than 6.6 m (except for the top floor), the width of no
more than 4.0 m and the floor load of no more than 4 kN/m2;
(2) The test building, office building and production accessory building of 4 stories and below supported
by dense transverse bearing walls with the main beam span of all floors of no more than 9.0 m(except for
the top floor), the width of no more than 4.0 m and the floor load of no more than 4 kN/m2;
                                                    15
(3) The factory building and test building of 4 stories and below with the main beam span of all floors of
no more than 7.5 m (except for the top floor), the floor load of no more than 10 kN/m2 and the total height
of building of no more than 15 m;
(4)   Less corrosive secondary factory building.
4.0.6 The selection of bearing structure types of a building shall comply with the related regulations of
the 《Code for Seismic Design of Building 》.



5.    Reinforced Concrete Single-Story Building


5.1 General Regulations
5.1.1 For the structure types of the single-story reinforced concrete factory building, priority shall be
given to the fabricated bent structure.
5.1.2 For the plan layout of the factory building, unevenness and tortuosity shall be avoided, the quality
and rigidity of all positions shall be distributed evenly and symmetrically, the body type of the factory
building shall be simple and regular.
Avoid the provision of overcrossing and overhead spans. When complicated plan layout has to be adopted
for production, deformation seam (or seismic seam) shall be used to separate it into independent and simple
body type units. When the height difference of multiple-span buildings is no more than 2 m, they should be
built in equal height.
5.1.3 The column space of the factory building shall generally be 6 m or 9 m. It may also be 12 m if
conditions permit. When V-shaped folded plate is used as roof, the multiple of 2 m or 3 m may be used.
The width of longitudinal skylight may take the multiple of 3 m.
For the determination of column cap height, the head room from the lowest part of the lower chord of roof
frame or beam (including the projection of lower chord brace) to the highest part of crane shall not be less
than 200 mm. If the foundation is possible to give rise to greater uneven settlement, this head room shall be
appropriately increased.
5.1.4 The end of the reinforced concrete bent factory building shall have roof frame and shall not be
supported by brick gable. Reinforced concrete column should be used as wind column. For expansion,
combination steel column may be used as gable column.
5.1.5 The arrangement of the factory building where there are heavy power machine and vibration shall
meet the following requirements:
5.1.5.1 The building foundation shall be separated from the foundation base plate of machine. The net
clearance between them should not be less than 150 mm with their base on a same elevation;
5.1.5.2 The operating and maintenance platform of the factory building shall be separated from the
foundation top of machine and the clearance between them should be 50~70 mm or they should be
connected with steel platform. The connecting points of the platform steel beam shall be reduced to
minimum and designed into a sliding bearing;
5.1.5.3 The support of high-pressure piping of the power machine shall not be directly placed on the wall
                                                     16
and column. A net clearance of 50~70 mm shall be reserved between the wall pipe and wall body.

5.1.6 The maximum space of the expansion joint of single-story fabricated reinforced concrete building
with bent structure shall comply with the regulations of Table 5.1.6.

                        Table 5.1.6 Maximum space of the expansion joint of
                           single-story Fabricated reinforced concrete bent

                         Type of structure                                  Maximum space of

                                                                             expansion joint (m)

  Column height of                           H<8                                      80
  factory building                      8 ≤ H ≤ 20                                   100
        H (m)                                H > 20                                  120
Note: ① Column height H refers to the full height from foundation top to column top;
     ② If there is sufficient basis or reliable measure, the value of maximum space of expansion joint
may be properly increased or decreased;
      ③ If there is heat no isolating measure on the roof or the expansion of horizontal component
material is great and the indoor structure is exposed for a long time due to construction, the space of
expansion joint should be properly reduced.
      ④ For the structure located in the area of arid climate and area with scorching sun and frequent
storm in summer or structure always under the action of high temperature, the space of expansion joint may
be properly reduced according to the experience in use


5.2      Main Points for Calculation
5.2.1      The structure of fabricated bent shall be calculated according the following regulations:
5.2.1.1     The column height of bent will be taken from the foundation top to the column top. When the
foundation is short-column cup-shaped foundation and does not comply with the requirements of article
3.3.3.2 of this code, the bent shall be considered as a three-stepped column and the column height shall be
taken from the short column base to column top;
5.2.1.2    The roof bean (or roof frame) and column top should be connected by means of elastic hinge.
For the single-span factory building where the lifting capacity of a crane is greater then 10 tons, the upper
column section shall be rechecked according to the fixed hinge.
5.2.2When the single-story factory building (such as air-compressor room, boiler room and others) is
provided with operating and maintenance platform, the calculation shall be conducted according to the
following calculation sketch with reference to the rigidity ratio of the platform column to the factory
building column:
5.2.2.1    When the rigidity ratio np< 1/20, the action of the platform column on the factory building
column may not be taken into consideration. When there is locally-hinged platform, the platform load
transmitted to the bent column may be calculated (see Fig. 5.2.2―1). When there is a full span hinged
                                                      17
platform, the platform plate may be taken as a horizontal connecting rod for calculation (see Fig. 5.2.2―2).
5.2.2.2 When 20≥np≥1/20, the joint action of platform column and factory building column shall be
taken into consideration to calculate by taking the platform column as an integral part of the bent (see Fig.
5.2.2―3).

5.2.2.3     When np>20, calculation may be conducted by taking the connecting point of platform and
factory building column as a fulcrum of the fixed hinge (see Fig. 5.2.2―4).

5.2.3 The rigidity ratio of platform column to factory building column (lower column) may be calculated
according to the following formula:




            Fig. 5.2.2-1 Calculation sketch of locally-hinged platform bent when np< 1/20




           Fig. 5..2.-2 Calculation sketch of full span hinged platform bent when np<1/20




                 Fig. 5..2.-3 Calculation sketch of platform bent when 20≥np≥1/20




                                                     18
           Fig. 5..2.-4 Calculation sketch of factory building with platform when np≥20

                       EpJp
                np                     (5.2.3)
                       ExJx
Where np— rigidity ratio of platform column to factory building column;
     ∑EpJp—section rigidity of all platform columns corresponding to the factory building of a same row;
     ∑ExJx— section rigidity of all factory building columns of a row.

5.2.4 The static calculation of bent structure shall comply with the provisions of articles 5.2.1 and 5.2.2.
The seismic calculation in the earthquake area shall be conducted according to the related provisions of the
《Code for Seismic Design of Building 》in force.

5.2.5The difference value of inertia moment between the assumed section for calculating the bent and the
finally-adopted section shall not be more than 30%, otherwise recalculation shall be done.
5.2.6For the single-span factory building with high rail level of crane (such as air compressor room etc.),
when the wind load is great (basic wind pressure W0≥0.5 kN/m2), the stress analysis of factory building
bent shall, apart from calculating according the crane load, take into consideration the non-existence of
crane. In such case, the calculated length of column shall take L0=1.5 H.
5.2.7 The calculated length of column of single-story industrial factory building with rigid roof shall
comply with the requirements of Table 7.3.1-1 in the《Code for Design of Concrete Structure》(GBJ
10-89).
5.2.8 When the wind column is fixed at its bottom and the column top or step changing place is
connected with the upper or lower chord of roof frame by means of spring plate, the calculation shall be
conducted according to the following three circumstances respectively:
5.2.8.1 If only the column top is connected by means of spring plate, the column top is calculated
according to the fixed hinge (see Fig. 5.2.8a);
5.2.8.2 If only the step changing place is connected by means of spring plate, the step changing place is
calculated according to the fixed hinge (see Fig. 5.2.8b);
5.2.8.3 If both the column top and step changing place are connected by means of spring plate, the
column top and step changing place are calculated according to the fixed hinge (see Fig. 5.2.8c). The
simplified calculation may be conducted according to Fig. 5.2.8d.



                                                    19
 (a) Column top         (b)Step changing      (c)Both column top and      (d)Simplified calculation
     connection         place connection      step changing place         when both column top and
                                              connection                  step changing place are
                                                                          connected

                                Fig. 5.2.8    Calculation of wind column
5.2.9 In calculating the bearing capacity of wind column, the wind load from the gable shall be considered
as the main load.
Except for its dead weight, if there is no other load action and only wind load from the gable, the wind
column shall be calculated as the bent component.
Except for its dead weight, if there is other vertical load action (such as the weight of brick wall over the
wall beam), the wind column shall be calculated as the eccentrically-stressed component. The calculated
length of the column shall be adopted according to Table 5.2.9.

                             Table 5.2.9 Calculated length of wind column
 Connection              Both the column top Only the column top Only the step changing place
                         and step changing is connected to the of column is connected to the
                         place are connected to roof frame or roof roof frame
                         the roof frame         beam

 Rigid     connection       Upper column             Upper column              Upper column
 between bottom and
                            L0=1.5Hu                 L0=2.0Hu                  L0=2.5Hu
 foundation




                          Lower column              Lower column              Lower column
                          L0=1.0HL                   L0=1.25HL                 L0=1.0HL
Note: In the table l0— calculated length;
                   Hu— upper column height;
                   HL— lower column height.

                                                     20
5.2.10 For the factory building with vibrating equipment (such as forge hammer building), the influence
of machine vibration on the building structure shall be taken into consideration. The additional vertical
dynamic load of roof structure may be calculated according to the related provisions of the《Code for
Foundation Design of Power Machine 》.

5.2.11 For the bent analysis of the factory building with a large area of stacked material (such as bulk
urea storehouse, phosphate fertilizer ripening storehouse and iron ore raw material storehouse etc.) shall,
apart from the identity with ordinary bent, take into consideration the adverse influence of the column
foundation rotation on the column as a result of the uneven settlement of foundation caused by stack load.
When the ground equivalent uniform load is less than the reference value listed in Table 5.2.11, the above
influence may not be taken into consideration.

                       Table 5.2.11 Reference value of allowable ground load (qg)

    Es (N/mm2)                5             6              7          8           9          10

    Qg (kN/ m2)             30             35             40         45          50          55

Note: Es is the compression modulus of soil layer within the range of foundation compression. For multiple
soil layer, Es is the weighted means of compression modulus of soil layer (according to the thickness of soil
layer).
5.2.12    For the prefabricated reinforced concrete column, its bearing capacity has to be calculated,
moreover the lifting strength shall be checked. On this occasion, the dead weight of column shall be
multiplied by the dynamic coefficient 1.5. The reinforcement stress may be calculated approximately
according to the following formula:

                       M
             s                             (5.2.12 )
                    0.87 ho AS
where M—design value of moment at the checked section;
     ho—effective height of cross section of the moment acting plane;
     As—reinforcement tension area of the checked section.

5.2.13    The calculation of bent wind load shall comply with the following regulations:
5.2.13.1 Distributed rectangularly along the factory building height. For the column top and above, the
concentrated load acts on the column top and its moment action on column top is generally not taken into
consideration. When the direction of concentrated horizontal wind load is opposite to the wind direction
(when the wind acting on roof is a suction force), its action may be neglected (except the open factory
building);
5.2.13.2 For the coefficient of change of wind pressure with altitude, if there is a rectangular skylight
above the column top, the value will be taken at the elevation of skylight eaves. If there is no skylight, the
value will be taken at the elevation of factory building eaves. Below the column top, the value will be taken
at the elevation of column top;
5.2.13.3 The body type coefficient of wind load shall be adopted according to the 《Code for Building
Structure Load 》. The open factory building with rain screen should be deemed as a closed one, but the
suction force on the roof is checked still according to the open one.

                                                     21
5.3   Column
5.3.1 The section design of the reinforced concrete bent column should comply with the following
requirements:
5.3.1.1 Cast-in-place column should adopt rectangular column;
5.3.1.2 Prefabricated column: When the section height is less than 800 mm, rectangular column should be
adopted. When the section height is 800~1,200 mm, H-shaped column should be adopted. When the
section height is more than 1200 mm, double-limb column should be adopted.
5.3.2 For the factory building with a column space of 6 m, the column section size shall meet the
requirements of Table 5.3.2, otherwise the lateral rigidity of the bent shall be calculated. The common
column section size may be selected from Appendix B.
5.3.3 The grade of concrete strength of reinforced concrete column shall not be less than C 20 and that of
prefabricated column should adopt C 25 and C 30.
5.3.4 The structure of factory building column in the earthquake area shall comply with the requirements
of the 《Code for Seismic Design of Building 》 in force.

5.3.5 The design of gable wind column shall comply with the following regulations:
5.3.5.1 For the gable wind column, reinforced concrete column shall be used. If the column with uniform
section is used, the column section b×h shall not be less than 350 mm × 600 mm. If stepped column is
used, the upper column shall not be less than 350 mm ×350 mm and the lower column should be
H-shaped or rectangular column, its section size shall comply with the requirements of the following
formula:
        h ≥ 1/25 Hx, and h ≥ 600 mm                   (5.3.5 – 1)
        b ≥ 1/35 Hy, and b ≥ 350 mm                   (5.3.5 – 2)
Where Hx—distance from the foundation top to roof frame or lower point for connection between wind
truss and column;
       Hy—maximum distance between two points in the direction of column width, except for the
connecting point of column with roof frame and foundation, the wall beam connected with column by
anchor bar and the wall board rigidly connected with column may be deemed as a fulcrum.

          Table 5.3.2 Minimum section size of solid spandrel column with 6 m column space
          Item     Illustration          Subelement                 Section         Section width
                                                                    height
                                                                      H                   b
  Factory                              Single span                   H/18      H/30 and  300mm
  building                                                                     Pipe column H/105
  without crane                        Multiple span                 H/20    and D3100mm
  Factory                              Q10t                         Hk/14    H1/25 and  300mm
  building with                        Q=15t 10mHk12m              Hk/12
  crane                                20t     Hk10m               Hk/11   Pipe column Hk/85 and
                                       Q=30t Hk12m                  Hk/11      D400mm

                                                     22
                                                  Hk10m             Hk/10
Note: ① Q is lifting weight, H is the total height from foundation top to column top, Hk is the height from
foundation top to crane beam top, H1 is the height from foundation top to crane beam bottom, r is the radius
of single-pipe gyration of the pipe column, D is the single-pipe outside diameter of the pipe column;
     ② Section height (h) shall be multiplied by coefficient 1.1 for the double-limb column with a flat
web member;
      ③ The crane is controlled on heavy duty. If it is controlled on medium or light duty, the section
height (h) may be multiplied by coefficient 0.95;
      ④ When the column space is 9 m or 12 m, the minimum section size should be multiplied by
coefficient 1.05 or 1.1;
      ⑤ When the roof is of purlin system without longitudinal and horizontal bracing at the lower chord,
the column section size should be properly enlarged.
5.3.5.2 The wind column should be arranged at the panel points of upper and lower chords of the roof
frame, otherwise the wind beam shall be arranged at plane positions of upper and lower chords of the roof
frame. The structure of panel point between wind beam and wind column shall be flexible connection in the
vertical direction and shall have effective transmission horizontal force;
5.3.5.3 The flexible connection between wind column and roof frame shall use spring sheet steel which
can vertically deformed (δ= 6~10 mm), the clearance between variable cross-section of column and
lower chord of roof frame shall not be less than 150 mm.
5.3.6 In the factory building where the column corner may be collided, the column corner has to be
protected with angle bar and the height of protection should not be less than 2.5 m.


5.4   Bracing System
5.4.1 The arrangement of bracing structure system shall take into consideration the span, height and
length (or expansion joint sector length) of the factory building, arrangement of column wire, selection of
structure types, crane lifting capacity and rail top elevation, existence of skylight, existence of vibrating
equipment, existence of special horizontal load and other factors and shall be determined after
comprehensive analysis.
5.4.2 The erection and structure of bracing in the factory building of earthquake area shall comply with
the related provisions of the《Code for Seismic Design of Building 》.

5.4.3 The erection and structure of column bracing in the factory building shall comply with the
following principles:
5.4.3.1. Under normal operating condition, in case of one of the following conditions, in the middle or near
the expansion joint sector length shall be erected the upper and lower column bracing, otherwise the action
of longitudinal horizontal load on column shall be calculated in design:
(1) There is a crane of medium and light duty with a lifting capacity of greater than or equal to 10 tons;
(2) There is a hanging crane with a lifting capacity of greater than or equal to 3 tons;

                                                      23
(3) The factory building span is greater than 18 m or column height is greater than 8 m;
(4) In the factory building with a column space of 6 m, the number of longitudinal column per row is less
than 7.
5.4.3.2 In case of one of the following conditions, an upper column bracing shall be erected on the first or
second column at both ends within the expansion joint sector and identical with the position of roof
bracing:
(1) When the roof frame has an upper chord or lower chord lateral horizontal bracing;
(2) Factory building with a crane of which the rail top elevation is greater than or equal to 8 m;
(3) Factory building with vibrating equipment.
5.4.3.3 If there is no suitable member on the column bracing to transmit the horizontal force, a
longitudinal rigid horizontal tie rod of full length shall be provided on the column top;
5.4.3.4 If the column section height is greater than or equal to 600 mm, its lower column bracing shall be
designed with double pieces. The space between the double pieces shall be equal to column width minus
200 mm. If the space is less than 700 mm, its tie rod shall be a horizontal web member. If the space is
greater than or equal to 700 mm, its tie rod shall be an inclined web member.
5.4.3.5 The column bracing member shall be determined by calculation and the minimum specification
should comply with the following requirements:
Equilateral angle bar ∠ 75 × 6, inequilateral angle bar ∠ 75 × 50 × 6, decorative strip ∠ 50 × 5,
connecting plate is 10 mm in thickness, connecting bolt M16, welding seam 6―60.

5.4.4 The arrangement of roof bracing shall comply with the following provisions:
5.4.4.1 Upper-chord lateral horizontal bracing: When the large-size roof board and roof frame or beam
are welded at no less than 3 points, the factory building without skylight of which the span is less than or
equal to 18 m may not be provided with upper-chord lateral horizontal bracing. The factory building with
skylight shall be provided with upper-chord lateral horizontal bracing at both sides of the skylight;
5.4.4.2 If the lower chord of roof frame is provided with a hanging crane parallel or perpendicular to the
plane of roof frame, it is necessary to provide lower-chord lateral horizontal bracing according to the
following regulations depending on different conditions;
(1) For the stepped steel roof frame, when the roof frame is provided with a hanging crane parallel to the
plane of roof frame and if the rail is located within the plane of roof frame, a horizontal bracing shall
provided at the lower chord of roof frame in a the left or right space adjacent to this roof frame (see Fig.
5.4.4―1). If the crane rail is located between two roof frames and its vertical position is below the lower
chord of roof frame, a horizontal bracing shall be provided at the lower chord of roof frame in this roof
frame with crane rail (see Fig. 5.4.4―2). If the crane rail is located between two roof frames and its vertical
position is above the lower chord of roof frame, a horizontal bracing shall be provided each at the lower
chord of roof frame in two spaces adjacent to the space provided with crane rail (see Fig. 5.4.4―3).

(2) For the stepped or arched reinforced concrete roof frame, if it is provided with a hanging crane
perpendicular to the roof frame and the hanging crane can run to the separating joint of the factory building
unit, a lateral horizontal bracing shall be provided each at the lower chord of roof frame in the first space at

                                                      24
both sides of the factory building unit (see Fig. 5.4.4―4). If the hanging crane does not run to the
separating joint of the factory building unit, a lateral horizontal bracing may be provided each at the lower
chord of roof frame in the first space at both sides of the hanging crane rail (see Fig. 5.4.4―5).

5.4.4.3 When the lower chord of roof frame is used as the fulcrum of wind column , lower-chord lateral
horizontal bracing shall be provided;
5.4.4.4 If the lower chord of roof frame is provided with a full-length longitudinal horizontal bracing, a
lower chord lateral horizontal bracing shall be provided to form a closed bracing system;




 Fig. 5.4.4―1 The first case of lateral                Fig. 5.4.4―2 The second case of lateral
 horizontal bracing at lower chord of roof frame       horizontal bracing at lower chord of roof frame
 provided with a hanging crane                         provided with a hanging crane




                                                     25
                   Fig. 5.4.4―3 The third case of lateral horizontal bracing at lower
                            chord of roof frame provided with a hanging crane




Fig. 5.4.4―4 The fourth case of lateral                      Fig. 5.4.4―5 The fifth case of lateral horizontal
horizontal bracing at lower chord of roof frame              bracing at lower chord of roof frame provided
provided with a hanging crane                                with a hanging crane
5.4.4.5 In case of the following conditions, a longitudinal horizontal bracing shall be provided at the
lower chord of roof frame:
(1) The column top of the factory building is higher than 15 m;
(2) The crane is of medium duty, its lifting capacity is more than 20 tons or the crane is of heavy duty;
(3) In the factory building there is a piston air compressor with greater unbalance disturbing force or a
forge hammer of 5 tons and more.
5.4.4.6 Upper-chord full-length horizontal tie rod: When the roof is a large-size roof boarding without
skylight, such a tie rod may not be provided. If there is a skylight, a full-length stress horizontal tie rod shall
be provided at the middle of the roof beam within the range of skylight;
5.4.4.7 The thin-webbed girder with a span of less than or equal to 15 m and the roof with large-size roof
boarding may not be provided with other roof bracing than vertical bracing at the girder end which will be
provided according to the 《Code for Seismic Design of Building 》in force.

5.4.5 The calculated length l0 of all bracing members may be determined according to the following
regulations:
5.4.5.1 For the non-cross member, l0 = L (L is the distance between center of panel points).
5.4.5.2 For the member of which the intersection point is securely connected, its calculated length: inside
the plane l0 = 0.5L; outside the plane: L0 = L for a tie rod, l0=0.5L for a compression member if two cross

                                                        26
members do not break, , but if the cross members break and are connected with panel, take l0 = 0.7L.


5.5 Roof Structure
5.5.1 The roof structure of single-story factory building and empty building should give priority to the
prestressed structure combining beam with slab (such as V-shaped folded plate, T-shaped plate etc.) or may
adopt the prestressed structure without purlin system (such as prestressed large-size roof boarding, hollow
slab, prestressed roof beam, roof frame etc.). For the roof with explosion-proof requirement, the
pressure-relievable light-weight roof should be adopted (the roof weight is less than or equal to 1.2 Kn/m2).
5.5.2 The packing and finished product storehouse and large column wire workshop may use wire frame
or solid truss.
5.5.3 The factory building of which the roof is provided with hanging crane or vibrating equipment
should use prestressed reinforced concrete roof beam or steel roof frame.
5.5.4 The factory building with corrosive medium shall use pretensioning prestressed concrete member as
the main bearing member of the roof structure. For the selection of member type, beam structure with
smooth appearance or corrosion-proof structure should be used instead of thin-walled member and
combination member.
If the member surface is not protected, the allowable value of maximum crack width for all members is
0.15 mm for roof frame, 0.20 mm for roof beam and 0.20~0.25 mm for main beam. If they contain
chlorine, hydrogen chlorinate or acid fog gas, the above value shall be reduced by 0.05 mm.
5.5.5 The roof load of petrochemical single-story building shall, apart from complying with the 《Code for
Structural Load of Building 》 in force, take into consideration the following conditions:

5.5.5.1 Reinforced concrete waterproof roof should reserve a load of 0.3 kN/m2;
5.5.5.2 In designing roof frame or roof beam, the indoor suspended pipe load should be taken into
consideration, the ordinary pipe (such as heating and ventilation pipe) shall adopt 0.05~0.1 kN/m2, while
the process pipe shall be handled according to the actual condition;
5.5.5.3 For the roof frame, the strength of web member in the course of construction and hoisting shall be
checked and its design load shall take into consideration the dead weight of roof boarding and construction
load of 0.5 kN/m2 within the range of half span.
5.5.6 The checked load of reinforced concrete prefabricated member in the form stripping, hoisting and
transport stages shall be used according to the following regulations:
5.5.6.1 The dead weight of the member shall be multiplied by dynamic coefficient 1.5. In calculating the
strength of roof frame web member, it may be multiplied by 1.0;
5.5.6.2 The absorptive power of form in stripping generally is 1.0 kN/m2.


5.6 Lifting Beam
5.6.1 The lifting beam of the factory building shall adopt reinforced concrete structure or prestressed
concrete structure and shall give priority to the universal members.

                                                     27
5.6.2 The selection of lifting beam type shall comply with the following regulations:
5.6.2.1 For the column space of 6 m, crane in medium or light duty and lifting capacity of less than 20
tons, the reinforced concrete structure should be used. For the lifting capacity of 20~30 tons, the
prestressed concrete structure should be used;
5.6.2.2 For the column space of 6 m, crane in heavy duty and lifting capacity of less than 15 tons, the
reinforced concrete structure may be used. For the lifting capacity of 15~30 tons, the prestressed concrete
structure should be used;
5.6.2.3 For the column space of 9 m or 12 m, crane in medium or light duty and lifting capacity of less
than 15 tons, the prestressed concrete structure should be used;
5.6.2.4 The factory building with gas-phase corrosive action and moisture should give priority to the use
of prestressed concrete lifting beam.
5.6.3 For the lifting beam bearing medium or heavy duty, its longitudinal tension reinforcement shall not
use tied joint nor welded joint and no attachment (except for end anchor) shall be welded on the
reinforcement. The lifting beam shall not use open hooping.


5.7 Building Enclosure and Others
5.7.1 The enclosure of the factory building should be built with bolted lightweight slabs or lightweight
blocks. The high-span enclosing wall at the high and low span should use lightweight wall slab of
lightweight wall.
5.7.2 The brick enclosure wall of the factory building should be of outside facing; the wall shall be
integrated with the building column.
5.7.3 When partition wall is built within the factory building, the top of wall shall have integrally-cast
coping beam and no cantilever wall shall be used. When there is high partition wall in the workshop,
reinforcing strip shall be added every 3 m or so along the wall height in addition to the coping beam on the
top of wall.
5.7.4 The erection and structure of gird and girt for the brick enclosure wall shall comply with the
following regulations:
5.7.4.1 The single-story factory building with reinforced concrete column shall have a gird or girt near
the top of column or wall;
5.7.4.2 For the factory building without crane, when the wall is 6 ~11 m in height, a gird or girt shall be
added at the mid-height of the wall;
5.7.4.3 For the factory building with crane, when the wall is less than 11 m in height, a gird or girt shall
be added each near the lifting beam and proper position of the wall;
5.7.4.4 For the factory building with power-driven machine, more than 1 ton forge hammer and other
large vibrating equipment, gird or girt shall be added about every 4 m along the wall height;
5.7.4.5 When the brick enclosure wall of a single-story factory building is more than 18 m in height, the
high-span enclosing wall of the high and low span factory building shall be provided with wall beam;

                                                    28
5.7.4.6 The gird shall be more than or equal to 180 mm in height, the width is generally identical to wall
thickness, the grade of concrete strength is no less than C 15, the longitudinal reinforcement should not be
less than 4 φ10, the overlapping length of the tied joint shall be considered with reference to the tension
reinforcement and the space of sealed hooping should not be more than 300 mm.
5.7.5 When the span of the factory building is less than 15 m and the height is more than 12 m, a wind
beam should be provided inside the gable. The width of the gable is 1/15 ~ 1/20 of the span. Both ends of
the gable shall be securely connected with the building column.
5.7.6 The wall foundation of the factory building should adopt the prefabricated reinforced concrete
foundation beam. Strip foundation shall be used between columns in the factory building where heavy-duty
truck may come in.
5.7.7 The requirement for building enclosure and the erection and structure of gird of the factory building
in the earthquake area shall comply with the provisions of the 《Code for Seismic Design of Building 》
in force.



6.   Reinforced Concrete Multiple-story Factory Building


6.1 General Regulations
6.1.1 The multiple-story building which complies with one of the following conditions should adopt
reinforced concrete structure or prestressed concrete structure:
6.1.1.1 Factory building of which the petrochemical production plant is equipped with important
equipment;
6.1.1.2   Factory building with anti-vibration requirement;
6.1.1.3   Factory building with anti-explosion requirement;
6.1.1.4   Factory building with high corrosive medium and air humidity;
6.1.1.5   Open or semi-open factory building;
6.1.1.6   Factory building with more piping through holes and difficulty to adopt brick wall bearing.
6.1.2 The factory building with anti-vibration and explosion-proof requirements, more and big holes on
the floor and high anti-corrosion requirement should adopt cast-in-place reinforced concrete structure.
6.1.3 In a unit of same frame, staggered layer, interlayer and other circumstances shall be avoided. In the
earthquake area, if it is required by production, anti-seismic check shall be carried out according to the
actual rigidity and structural measure shall be taken.
6.1.4 For the factory building of 4 stories and below, the column section size shall be the same as far as
possible. For the factory building of more than 4 stories, the column section size should not exceed 2 kinds.
The short-side size of the cast-in-place column should not be less than 300 mm and that of the prefabricated
column should not be less than 350 mm. The beam width shall be less than the column width and its value
shall not be less than 50 mm.
6.1.5 The frame structure should adopt the plan of bearing with transverse frame, but if the length and
                                                     29
load of frame in the longitudinal and transverse directions are close or the main stress direction is unclear,
they shall be calculated in these two directions.
6.1.6 The center lines of the frame beam and column should be within a same plane. If there is any offset,
the offset distance should not be more than 1/4 of the side length corresponding to the column section and
the adverse influence of offset on the core area of panel point and column stress shall be taken into
consideration.
6.1.7 The fabricated frame should adopt the plan of rigid connection of transverse load bearing. When the
factory building has only a few stories and can make use of the rigid wall, the plan of hinge joint may be
adopted. The longitudinal frame may adopt the plan of rigid connection or hinge joint. If the plan of hinge
joint is adopted, the expansion joint sector shall generally be provided with column bracing or rigid span.
6.1.8 If the floor is precast slab, the slab surface should have an integrally-cast reinforced concrete layer
of 50 mm in thickness.
6.1.9 The guard structure of the factory building should give priority to the light aggregate concrete wall
board or reinforced concrete wall board. If masonry is adopted, lightweight blocks should be used.
6.1.10 The factory building with dynamic load action and anti-corrosion requirement and located the
anti-seismic area shall comply with the regulations of the related special code.


6.2 Analysis of Frame Internal Force
6.2.1 The calculated length of the frame column shall be determined in accordance with the following
regulations:
6.2.1.1 Generally the calculated length l0 of the frame column of the multiple-story building shall comply
with the regulations of Table 6.2.1.

                         Table 6.2.1 Calculated length of reinforced concrete frame

       Floor type                            First floor                   Other floors

      Cast-in-place                          1.00 H                          1.25 H

      Fabricated                             1.25 H                          1.50 H

Note: H is the column height, the story is based on the story height, the first floor takes the distance from
the foundation top or foundation beam top to the first floor ceiling top.
6.2.1.2 For the frame structure which can be considered as no lateral displacement, if the building with
non-lightweight partition wall has three spans or more than three spans or has two spans with a rise-to-span
ratio of less than 3, the calculated length of the column is as follows:
      Cast-in-place floor                  l0 = 0.7 H
      Fabricated floor                     l0 = 1.0 H
6.2.2 For the cast-in place frame structure, when the floor has no opening and the floor thickness is no less
than 0.1 time of the beam height, the inertia moment of the beam section of the middle frame beam may be
determined by double inertia moment of rectangular section, while that of the side frame by 1.5 times of the

                                                        30
inertia moment of rectangular section. However when the floor has more or large openings, the inertia
moment of the beam should be calculated according to the rectangular section.
For the beam with support, when the ratio of height of the beam support section to that of the beam span
intermediate section, the influence of support on the beam rigidity shall be taken into consideration.
6.2.3 The calculation of internal force of the cast-in-place reinforced concrete frame shall comply with the
following regulations:
6.2.3.1 Under the action of vertical load:
(1) In calculating the multiple-layer and multiple-span frame, generally the lateral displacement may not
be taken into consideration, except for the asymmetric load or irregular shape of frame;
(2) For the multiple-layer and multiple-span frame structure (see Fig. 6.2.3―1), when the ratio of
beam-column linear rigidity at the panel point is no less than 5, the beam may be calculated according to
the continuous beam (see Fig. 6.2.3―2), the moment of the internal column may not be taken into
consideration, but the end moments of side column and side-span beam have to be calculated.
The fixed-end moment of side-span beam shall be distributed according to the following formula (see Fig.
6.2.3―3)
                           iac
                M ac         Ma              (6.2.3  1)
                           ia
                          iac
               M ad          Ma              (6.2.3  2)
                          i a

The end moment of beam is calculated according to the following formula:
             Mab = –(Mac + Mad)                (6.2.3―3)
Where Ma— fixed-end moment of single-span beam;
      Mac— moment of column ac at a end;
      Mad— moment of column ad at a end;
       iac— linear rigidity of column ac;
       iad— linear rigidity of column ad;
      Σic— sum of linear rigidity of all members at panel point a.




                        Fig. 6.2.3―1 Multiple-layer frame schematic diagram




                                                    31
                                Fig. 6.2.3―2 Calculation of frame beam




          Fig. 6.2.3―3 Distribution of side-span beam-column moment schematic diagram

(3) For the multiple-layer and multiple-span frame structure, when the ratio of beam-column linear
rigidity at the panel point is less than 5 or when the ratio of rigidity is no less than 5 but the span and load
differ greatly, its internal force shall be calculated according to the analysis of the integral frame;
(4) When the column wire is relatively special, the structure form is asymmetric and the live load is
greater than static load, a more accurate calculating method should be adopted;
(5) In calculating the load transmitted from main beam to frame and the load transmitted from main beam
to frame, the continuity of beam may not be taken into consideration.
6.2.3.2 Under the action of horizontal load:
(1) When the form of frame is regular, the ratio of beam-column linear rigidity at the panel point is no
less than 5 or when the rigidities of beam and column of two adjacent layers do not differ very much,
approximate method may be adopted for calculation. The horizontal shear born by the columns may be
distributed in proportion to the shear rigidity of column. The points of inflection of columns are at 2/3 H
from the bottom for the ground floor and 1/2 H for other floors, while H is the floor depth;
(2) For the frame structure with its rise-to-span ratio of greater than 3 and wind load as the main load,
more accurate method should be adopted for calculation.
6.2.4 The cast-in place frame shall be calculated according to the elastic stage, generally the redistribution
of internal force caused by plastic deformation may not be taken into consideration.
6.2.5 In calculating the section area of support reinforcement of frame beam, the negative bending moment
value at the column edge shall be taken. If the moment under the action of wind load is great and the
vertical load is small, the positive bending moment at the support shall be checked.
6.2.6 After the analysis of internal force, when the rigidity of the member section that is used and that of the
originally assumed member differ by 2 times, the internal force of the frame shall be analyzed once again.
6.2.7 The negative bending moment at the beam end under the action of vertical load should be modulated
by 10 ~ 20%.
6.2.8 The static calculation of the fabricated integral frame shall comply with the following regulations:
6.2.8.1 The static calculation of frame is conducted in two stages:
(1) The first stage is a stage of construction and installation: The prefabricated beam is simply supported
on the column bracket. At this time the panel point of the frame rigidity has not yet been taken shape. If no
                                                      32
support is erected during construction, the load is the dead weight of beam (including the weight of
laminated layer and grouted joint) and construction load standard value of 1.5 kN/m2. When the span is
large and temporary support is erected, the calculation shall be done according to the actual conditions;
(2) The second stage is a stage of operation: The panel point of the frame has the rigidity required by the
design and the multiple-layer integral frame has taken shape. The load is composed of the live load of floor
(including the weight of equipment and hanging crane), the weight of integrally-cast layer and finishing
layer, wind load, wall and other load, but the construction load standard value of 1.5 kN/m2 shall be
deducted.
6.2.8.2 In analyzing the internal force, the section inertia moment of frame beam shall take into
consideration the action of flange. When the integrally-cast layer of the floor is no less than 50 mm in
thickness, the section inertia moment of the intermediate frame beam takes J = 1.5 Jo, while the that of the
side frame beam takes J = (1.2 ~ 1.3) Jo. In case of floor with more or large openings, J value shall be
calculated according to the rectangular section;
Note: Jo is the inertia moment of rectangular section (b × h).

6.2.8.3 For the reaction of support caused by the frame column under the action of beam load at the first
stage, its offset action on the column shall be calculated according to the actual conditions.
6.2.9 The filler wall in the frame shall be securely connected with the frame. For calculation, the bearing
capacity of the filler wall shall not be taken into consideration, but the influence of part of rigidity of the
filler wall on the base period of the frame shall be taken into consideration, namely multiply the calculated
base period of the frame by the influence coefficient K of the filler wall and the K value takes 0.5 ~ 0.8.
6.2.10 Expect for the regulations stipulated in this section, the analysis of earthquake action on the frame
shall comply with the related regulations of the《Code for Seismic Design of Building 》.



7    Buildings of Brick-Concrete Structures


7.1 General Regulation
7.1.1 Buildings of brick-concrete structures shall have good integral rigidity and stability and its structure
shall be arranged on the following principles:
7.1.1.1 It is preferable to have load born by transverse walls or by both longitudinal and transverse walls.
A bearing wall shall have vertical continuity.
7.1.1.2 The transverse walls should be so spaced that the requirements of the rigid load plan can be
satisfied. A transverse wall itself shall have sufficient rigidity and its thickness, length and opening shall
meet the requirements of the rigid load plan for transverse walls.
7.1.1.3 A longitudinal wall shall run through all the way and any breakings or turnings shall be avoided.
7.1.1.4 The door and window openings on all floors shall line up vertically. Any too big opening shall be
avoided in the main bearing walls. The vestibule shall have good integrity and any nonuniform stressing
shall be prevented.
7.1.1.5 For Internal multi-storey framework, a plan of double row columns extending to the roof is
                                                      33
preferred. The floors and roof should of a fabricated integral reinforced concrete structure.
7.1.1.6 Any wide-span bay should be located in the middle of the top floor. A staircase should not be
situated in an end bay or at the corner of L-shaped buildings.
7.1.1.7 Heavy and vibration generating equipment should be located on the ground floor.
7.1.2 For a complicatedly-configured brick building situated on weak soil, swelling and shrinking soil,
collapsible loess or filling soil, settlement joints shall be provided to divide it into a number of independent
units with simple configuration and high spacial rigidity. It is advisable to build double walls at the
settlement joints. The locations and width of the settlement joints shall meet relevant stipulations in the
current version of Code for Design of Base and Foundations of Building.
7.1.3 Settlement joints shall be made for any brick outbuilding adjacent to the main building. If an
overhanging foundation is used to separate it from the main building and no double walls are built,
constructional columns shall be added at the ends of walls. The cross section of such a column shall be no
less than 240mm×240mm. The upper ends of longitudinal bars of the column shall be anchored to the
floor or roof beam by a length of 40d (d is the diameter of a longitudinal bar of a constructional column).
7.1.4 Recessing or opening is strictly forbidden within the load transfer areas under the brick columns,
brick wall posts and beam seats.
7.1.5 An expansion joint shall be made in accordance with the relevant stipulations in the current version
of Code for Design of Masonry Structure. Aseismatic, settlement and expansion joints shall be arranged in
an unified way.
7.1.6 The earthquake resistance of multi-storey brick buildings shall be as required by relevant
stipulations in the current version of Code for Seismic Design of Buildings.


7.2 Rules for Calculations
7.2.1 For a brick-and -concrete structure, three static calculation plans are available, namely the plan for
rigid load, the plan for rigid and elastic load and the plan for elastic load, depending on the spacial rigidity
of the building. The calculation plan, scheme and rules shall be determined according to relevant
stipulations in the current version of Code for Design of Masonry Structures.
7.2.2 For safety classes of brick masonry buildings, ordinary buildings and major or big buildings for
auxiliary production will be of class 2 while minor or small buildings class 3.
7.2.3 If checking calculation of rigidity of any transverse wall is needed in determining rigid load plan or
rigid and elastic load plan and the total level section area of door and window openings is no more than
75% of that of the wall, its maximum horizontal displacement can be determined as below:


                      mPH 3 2nPH    H
            m ax                                       (7.2.3)
                       6 EI   EA   4000
Where
max is the maximum horizontal displacement of the transverse wall;
P is the sum of the concentrated wind load (W) on the lower chord of roof truss and the column top
                                                      34
reaction (R) determined from uniformly distributed wind load on the longitudinal wall in case of no lateral
displacement of bent, i.e., P=W+R;
n is the number of bays between two transverse walls adjacent to the above-mentioned transverse wall;
E is the elastic modulus of masonry;
H is the height of the transverse wall determined in accordance of 7.2.5 in this code;
I is the moment of inertia of the transverse wall, which is to be taken approximately based on the gross
section of the wall for simplification of calculation and can be considered based on I-or [-shaped section
when the transverse wall adjoins the longitudinal ones, in which case the calculated breadth of the portion
of the longitudinal wall working together with the transverse one on either side shall be taken as 0.3H, i.e.,
br=0.3H;
A is the level gross section area of the transverse wall.
7.2.4 A wall shall be so designed that the requirement for stability can be satisfied. Checking calculation
of stability shall be conducted or constructional measures taken for the following walls of a building:
7.2.4.1 Walls of staircase on top floor;
7.2.4.2 Broad gable without tie on either side of a pitched roof;
7.2.4.3 Tall parapet without tie on end of a roof truss;
7.2.4.4 Exterior longitudinal wall with no side edge of floor slab extending into it or exterior wall without tie;
7.2.4.5 Seal wall at high span portion of a high and low span building;
7.2.4.6 Tall or long partition wall or half brick wall;
7.2.4.7 Small-breadth bearing wall between;
7.2.4.8 Bearing wall with relatively large section attenuated by opening;
7.2.4.9 Wall at an overhanging inserted member (e.g. balcony, rainshed and cornice, etc...);
7.2.4.10 Suspended wall at the intersection of longitudinal and transverse spans;
7.2.5 Height of a wall shall be determined as specified below:
7.2.5.1 The height of an exterior wall on the ground floor will be measured from the ceiling of the first
floor to 500mm below the outdoor ground or to the bottom of pipe trench at the exterior wall;
7.2.5.2 The height of an interior wall on the ground floor will be taken as that of the storey. This also
applies when there is any trench below, on the cover plate of which, however, concrete bedding is placed.
Otherwise the wall height will measure down to the bottom of the trench;
7.2.5.3 The height of the interior and exterior walls of a storey above the ground floor will be taken as
that of the storey;
7.2.5.4 For a building with pitched roof, the height of the top storey will be measured to the average
height of the gable;
7.2.5.5 The height of an exterior longitudinal wall of a single-storey building will be measured from the
seating surface of the roof beam (roof truss) to 500mm below outdoor ground or to the bottom of the pipe

                                                         35
trench;
7.2.5.6 When a prefabricated slab is placed in the direction of an exterior wall and the spacing S between
transverse walls is greater than u1u2 [] h with the values of u1,u2, [] and h being taken as specified in
chapter 5 of Code for Design of Masonry Structures GBJ 3-88, tie bars shall be provided at the side of the
slab in order to strengthen the tie between the exterior wall and the slab. In this case the height of the
exterior wall can be determined as specified in above 7.2.5.1 to 7.2.5.3.
7.2.6 When the basement floor or trench cover plate is used as the support of a basement wall or a trench
wall, backfilling can be done only after the basement floor slabs or trench cover plate are laid or grouted
otherwise the upper end of the basement or trench wall will be deemed as a free end.
7.2.7 In checking of static calculation of a brick wall pier, account shall be taken of the impact of
unfavorable conditions on the pier. When the pier is attenuated by a door or window head rail, inlaid brick
blocks and chiselling during construction, the calculated strength section shall be reduced by 300cm2. If
reduced section area A is smaller than 0.30m2, the strength of the brick masonry shall be multiplied by
adjustment factor a=0.7 + A (in m2). For checking calculation of the strength of a masonry unit partially
loaded, however, a will be taken as 1.
7.2.8 When a reinforced concrete girth acts as a lintel concurrently, the reinforcement for the lintel part
shall be separately arranged in calculated quantity.
7.2.9 In addition to the requirements indicated in this section, static calculation of a building and design
of walls shall comply with Code for Design of Masonry Structures.


7.3 Structural Requirements
7.3.1 Structure of walls shall meet the following requirements:
7.3.1.1 A wall must have a height to thickness ratio within the permissible range, which shall conform to
the requirement in Code for Design of Masonry Structures;
7.3.1.2 The breadth of a wall between window (or openings) shall be no less than 490mm when it bears
concentrated load and no less than 370mm when it bears no such load;
7.3.1.3 The distance between the verge of a door or window opening in a transverse bearing wall and the
inner edge of an exterior longitudinal wall shall be no less than 370mm. When a door or a window is
located in the wall on either side of a settlement or expansion joint, the verge of its opening shall be no less
than 1m apart from that of the joint and a reinforced concrete or reinforced brick lintel shall be provided at
the opening;
7.3.1.4 For a bearing wall having a horizontal channel reserved for a concealed pipe, the thickness of the
attenuated brick wall should be no less than 180mm and also no less than two thirds of the wall thickness,
and checking calculation of strength shall be conducted based on attenuated section;
7.3.1.5 A half brick wall shall be provided with wall posts or girths depending on the requirements for
stability. If it is higher than 3.6m, reinforced concrete or brick girth shall be located at a height no more
than 3.6m or at the top of the door or window. The girth is to be connected with the walls on both sides by
racking bond or reinforcement. Horizontal bars 2 6 shall be placed every 500mm along the height of the
wall and extended into the masonry on either side by no less than 500mm.
                                                      36
7.3.2 The girths shall be located by taking into consideration such factors as the layout of building, the
construction of structure, the load and geological conditions in a comprehensive way, and in accordance
with the requirements in relevant codes as well as the following stipulations.
7.3.2.1 For a single-storey building, a girth shall be placed along the exterior wall and the interior
longitudinal wall at the roof. Another girth shall be provided every 4 to 6m along the height of the wall
when it is 240mm thick and every 6m when it is 370mm thick;
7.3.2.2 For a building in which heavily vibrating equipment will be installed, a girth shall be provided
every 4m or so along the height of the wall;
7.3.2.3 Girths of an interior transverse wall shall be spaced by no more than 7m at the roof of a
multi-storey brick building and by no more than 15m at the floor. Where earthquake resistance is required,
Placement of girths shall comply with subclause 5.3.5 in Code for Seismic Design of Buildings (GBJ11-89).
All the interior transverse walls of a single storey building should be provided with girths, which can be
reduced in number appropriately when there are quite a few transverse walls. In the areas with
constructional columns, girths shall be located correspondingly;
7.3.2.4 For a building situated on weak soil, swelling and shrinking soil, collapsible loess or ground base
with varying soil layers, a girth shall be placed on the top of the foundation additionally. If the height of the
masonry under the lowest window is less than the window breadth, another reinforced brick girth should be
located below the lowest window sill elevation;
7.3.2.5 When cast in-situ reinforced concrete floor or roof is employed, stiffening measures can be taken
at the slab side without provision of girths;
7.3.2.6 In a structural unit plane, each course of girths should be placed on the same level in a continuous
way and possibly connected to form a closing ring;
When a girth is cut off by an opening, a supplementary reinforced concrete girth shall be placed in the
masonry over the opening. The section area of bars of the supplementary girth shall be no less than that of
the cut girth. These two girths shall be overlapping by a length no less than twice the distance between
them and also no less than 1.0m (See Fig. 7.3.2); When H is no more than 0.5m, the supplementary girth
can be turned upwards vertically and connected to the beam.
Where a girth is cut by other beam end, short bars no less than 410 in size can be embedded at
corresponding position of the beam end and overlapped with longitudinal bars of the girth. If a hole is
reserved at the beam end, the hole should be 20mm larger than the longitudinal bar of the girth in diameter
and filled with c20 fine stone concrete;
7.3.2.7 For a building designed based on rigid and elastic load plan or elastic load plan, the girths shall be
positively connected with members such as roof truss and girder;




                                                       37
                             Fig.7.3.2 Structural Illustration of a Cut Girth
7.3.2.8 For a cast in-situ reinforced concrete girth, the breadth of its section should be equal to the wall
thickness. When the latter is greater than or equal to 240mm, the former should be no less than two thirds
of the latter. The height of the girth shall be no less than 120mm and, in case of a spacious brick building,
no less than 180mm. The strength level of concrete to be used shall be no lower than c15. Normally Class I
bars will be used, with the longitudinal bars being no less than 410 in size for a general-purpose girth, no
less than 412 for a wind resisting girth and no less than 414 for a foundation girth. The stirrups to be
used will normally be of a diameter of 6 and a spacing of 250mm;
7.3.2.9 Reinforced concrete girth should not be exposed outdoors when they are used in an area where
the temperature varies greatly; which is liable to cause wall cracking.
7.3.3 A lintel should be made of reinforced concrete and it shall be constructed as specified below:
(1) The strength level of concrete shall be no lower than c20 for a prefabricated reinforced concrete lintel
and no lower than c15 for a cast in-situ one;
(2) Longitudinal stressed bars shall be of Class I or II while erection bars and stirrups of Class I;
(3) Shape of section and size: A lintel shall have a rectangular or L-Shaped section as required and a
height that suits the modulus of masonry;
(4) The bearing length of a lintel shall be no less than 240mm. In an area with a designed with stand
seismic intensity of 9, it shall be no less than 360mm. When a door and a window are close to each other,
caution shall be taken against collision between the lintel ends and resultant inadequate bearing length.
7.3.4 When the width of a door opening is greater than or equal to 3.0m, reinforced concrete door frame
should be provided and preferably cast in situ, with the concrete being of a strength level of c15. The cross
rail of the frame will be dealt with as an ordinary lintel or a rainshed beam. The longitudinal stressed bars
of the frame posts should be no smaller than 412 in size and overlapped with reserved joint bars of the
foundation (or foundation beam), which should be embedded in the foundation with an extension length no
less than 400mm. The posts shall be tied up with brick walls by bars 26 every 500mm.
7.3.5 If the roof truss and the beam bear on walls and wall posts, concrete pads shall be provided as
required by relevant current codes and checking calculation conducted for their local compressive strength.
The pads shall be constructed as specified below:
7.3.5.1 The concrete strength level shall be no lower than c15 and the pad thickness no less than 180mm;
7.3.5.2 Cast in-situ plain concrete pads can be used if they satisfy the requirement of rigid load transfer. If
they don’t, reinforcement shall be provided at the bottom;
7.3.5.3 When the span of a supporting beam is no less than 6m, the pads shall be provided with two
layers of reinforcement mesh with the total quantity of reinforcement used for each pad being no less than
0.05 percent of the volume of the pad;
7.3.5.4 If a bound skeleton is employed, closing stirrup shall be used as the pad reinforcement.
7.3.6 The walling material shall be selected as specified below:
7.3.6.1 The strength levels of bricks and mortar for common masonry shall be determined based on the
result of bearing calculation and no lower limit is set for it;
                                                      38
7.3.6.2 For exterior walls of a building with six or more stories, walls of a damp room or a room subject
to vibration or with a storey height over 6m, the strength level of the material shall be at minimum MU10
for bricks and M2.5 for mortar;
7.3.6.3 Mortar used for all walls on each floor should be of the same strength level or, if necessary, two
levels at most. Mortar used for each wall shall be of the same strength level. If a particular part of a wall
needs an higher strength level of mortar, the strength of mortar used for the entire wall should be enhanced
a level higher, or mesh reinforcement provided at this particular part;
7.3.6.4 A damp-proof course shall be laid in masonry under the indoor ground and over the top of
outdoor water table. Water-proof cement mortar should be used as the material of damp-proof course. In
such masonry where reinforced concrete girths are installed, the damp-proof course can be dispensed with.
7.3.7 The constructional columns of a building in a seismic area shall be provided in accordance with the
following stipulations in addition to the current Code for Seismic Design of Buildings, depending on the
designed withstand seismic intensity, number of stories of the building, type of structure and its lay-out:
7.3.7.1 If any canted brick walls are to be built as designed in the layout of any building, a constructional
column should be added at the cant location. The column should have a profiled section so that it can be
kept normal to the adjoining surface of the brick wall. Wall tie bars shall be furnished as specified;
7.3.7.2 For a single-storey building with a designed withstand seismic intensity of 8 or 9, constructional
columns should be installed at the corners of exterior walls and the intersections of interior and exterior
walls;
7.3.7.3 A constructional column can be built with a separate foundation, but it shall extend 500mm below
the outdoor ground or into the foundation girth and, where there is any trench, to the bottom of the trench;
7.3.7.4 The walls on both sides of aseismatic, expansion and settlement joints should be deemed as the
exterior walls of a building and constructional columns shall be installed at the corners;
7.3.7.5 The constructional columns shall be aligned and linked up vertically through the whole building
and must not be staggered among different stories. If there is any penthouse such as water tank and
staircase that projects locally over the main building roof and the constructional columns could not easily
run from the lower part of the building all the way through to the top of the penthouse, the constructional
columns at the corners of the water tank or staircase can be made extend into the walls on the top floor of
the building below by a length equal to the height of the top storey. The inserted constructional columns
shall be connected with the top girth and the next lower girth. Girths should be placed at the top and bottom
of the locally projecting penthouse;
7.3.7.6 For a wall with reinforced concrete constructional columns, the strength level of bricks should be
no lower than MU7.5 and that of mortar no lower than M2.5;
7.3.7.7 Generally bars of Class I and concrete of a strength level no lower than c15 should be used for
constructional columns.




                                                     39
8.   Semi-Underground Pumphouse

8.1 General Regulations
8.1.1 A semi-underground pumphouse shall be designed taking into consideration the effect of surface
water and variation in ground water level after the plant is put into operation in addition to the effect of
ground water.
8.1.2 The structure of a semi-ground pumphouse shall be selected in accordance with the following
requirements:
8.1.2.1 When the design maximum ground water level is lower than the floor level of the semi-ground
pumphouse, reinforced concrete bent structure shall be employed in one of the following conditions:
(1) a bridge crane to be installed;
(2) the pumphouse span >12;
(3) the height of the underground part of the pumphouse=2~3m;

(4) the total height of the pumphouse > 6m;
(5) the designed withstand seismic intensity  6.
8.1.2.2 When the design maximum ground water level is higher than the floor level of the semi-ground
pumphouse or the height of the underground part of the pumphouse is over 3m, the underground part shall
be of a cast in-situ reinforced concrete structure;
8.1.2.3 When the design maximum ground water level is higher than the floor level of the semi-ground
pumphouse, which is of locally semi-underground type with a buried depth no more than 1.5m, a cast
in-situ reinforced concrete pump pond separated from the pumphouse can be used.


8.2 Rules for Calculation
8.2.1 Calculation for a semi-underground pumphouse shall include that of bearing capacity of structural
members, that of anti-floating stability and check calculation of crack resistance and crack width.
8.2.2 The load of the above-ground structure of a semi-underground pumphouse and the effect of
earthquake shall be calculated in accordance with relevant stipulations in Code for Load of Building
Structures and Code for Seismic Design of Buildings.
8.2.3 Design load shall be used in calculation of strength of the underground structure while standard
load used in the remaining calculation.
8.2.4 The sub-element coefficient of load shall be taken as 1.3~1.4 for ground water load, 1.4 for live
load and 1.2 for remaining load.
8.2.5 In check calculation of float resistant stability, only permanent effect shall be taken into account for
resistance whereas variable effect and friction on side walls shall not. Stability safety factor is 1.05.
8.2.6 The maximum permissible crack width of the underground structure of the pumphouse shall be
0.25mm and appropriately reduced if the ground water is erosive.
                                                     40
8.2.7 The effective breadth B of an underground reinforced concrete wall bearing the above column load
shall be calculated based on a diffusion angle of 45 (See Fig. 8.2.7).




                                                  Column spacing

                         Fig. 8.2.7 Calculated Section Breadth of Reinforced
                                Concrete Wall Bearing above column load


8.3 Structural Requirements
8.3.1 Concrete used for the underground structure of the pumphouse should be of a strength level no
lower than c25 and an anti-seepage level as listed in Table 8.3.1.

                 Table 8.3.1 Allowable Value for Concrete Anti-Seepage Level (Si)

      Ratio of maximum acting head to thickness                    Anti-seepage level
              of concrete wall or slab (i)
                                                                          (Si)

                         < 10                                             S4

                        10~30                                             S6

                         > 30                                             S8

8.3.2 Construction joints of the underground structure of the pumphouse shall be arranged as specified
below:
8.3.2.1 The concrete of the baseplate shall be placed in a continuous way without any construction joint
made;
8.3.2.2 No vertical construction joint shall be made;
8.3.2.3 A construction joint should be located 500mm or more over the baseplate and not at the
intersection of the baseplate with the side wall;
8.3.2.4 A construction joint shall be kept away from any reserved hole and no less than 300mm apart
from the verge of the hole;
8.3.2.5 Reliable means shall be provided at a construction joint to ensure good binding the concrete
placed successively. Water stop construction should be added if necessary.
8.3.3 Movement joints of the underground structure of the pumphouse shall be arranged as specified

                                                    41
below:
8.3.3.1 The maximum spacing between the movement joints of a cast in-situ reinforced concrete structure
is 30m. If movement joints cannot be made as specified, post grouting zone can be provided;
8.3.3.2 The width of a movement joint should be no less than 20mm and the thickness of a slab (or a
locally thickened slab) at a movement joint no less than 250mm;
8.3.3.3 Settlement difference at a movement joint shall be no more than 30mm.




                                                  42
                          Annex A Value of Dynamic Coefficient 
                                    Table A     Value of Dynamic Coefficient 

Serial                                                     Weight of               Speed           Dynamic
 no.           Description of equipment                    equipment              (r/min)         coefficient
                                                               (t)                                    

1        Shaft rotating or motor              driven                                        no less
         light-duty machinery
                                                                                            than 1.2

2                                                      Weight or motor     300-400          1.2
                                                       Weight or motor     500              1.25
         Motor                                         Weight or motor     750              1.6
                                                       Weight or motor     1000             2
                                                       Weight or motor     1250             2.5
                                                       Weight or motor     1500             3

3                                                      Weight of machine 300-500            1.2
                                                       Weight of machine 750                1.35
         Centrifugal ventilator                        Weight of machine 1000               1.6
                                                       Weight of machine 1250               2
                                                       Weight of machine 1500               2.25

4        Extraction fan                                                                     1.5

5                              HP                      Weight of machine                    3

         Blower                MP                      Weight of machine                    2

                               LP                      Weight of machine                    1.2

6                                                      Machine+material    300-400          1.2
                                                       Machine+material    500              1.25
         Centrifugal pump                              Machine+material    750              1.6
                                                       Machine+material    1000             2
                                                       Machine+material    1250             2.6
                                                       Machine+material    1500             3

7        Caustic soda evaporator                       Machine+material                     1.5

8        Boiling bed reactor                                                                1.3-1.5
         (for water treatment)

                                                           43
Serial                                                Weight of        Speed           Dynamic
 no.              Description of equipment            equipment       (r/min)         coefficient
                                                          (t)                             

9        Screw conveyor                           Machine+material              1.5

10       Cyclone dust extractor                                                 1.2

11       Reaction drum                                                          1.5

12       Air filter and air drum                                                1.2

13       Rotary screen                            Machine+material              1.5

14       Suspension screen                        Machine+material              2

15       Rotating packer                                                        1.2

16       Vacuum unit                                                            4

17       Caustic filter                                                         1.5

18       Agitator                                 Machine+material              1.5

19                      Driving unit and          Machine+material              1.4
         Bucket         Head section

         lifter         Middle        and    lower Machine+material             1.2
                        supports

20       Gantry crane                             Machine+lifted                1.3
                                                  load

21       Vibration screen                         Machine+material              4

22       Electric winch                           machine                       1.1

23       Ball mill      Static weight  40kN                                    5

                        Static weight < 40kN                                    4

24       Crusher        Jaw type                  Machine+material              5

                        Cone type                 Machine+material              5

                        Hammer type               Machine+material              4

                        Roller type               Machine+material              3




                                                       44
                   Annex B      Common Column Section Dimensions

When column spacing of a building is 6m, buried foundation depth no more than 2m and normal wind load
value no more than 0.70kN/m2, rectangular column section dimensions can be taken from Table B-1-2
while I-shaped column section taken by referring to the table.

       Table B-1 Column Section Dimensions of a Building with a Light-or Medium-Duty Crane

                  Rail top       Column Section b×h (mm×mm)

Crane load        height         Side column                       Middle column

(t)               (m)            Upper column     Lower column     Upper column     Lower column

2-5               6-8            350×350          350×600          350×400          350×600

10                8              400×400          400×700          400×500          400×800

                  10             400×400          400×800          400×500          400×800

15-20             8              400×400          400×800          400×500          400×800

                  10             400×400          400×900          400×600          400×1000

                  12             500×400          500×1000         500×600          500×1200

30                8              400×400          400×1000         400×600          400×1000

                  10             400×500          400×1000         500×600          500×1200

                  12             500×500          500×1000         500×600          500×1200

                  14             600×500          600×1200         600×600          600×1200



                 Table B-2 Column Section Dimensions of Buildings without Cranes

Column height                    Column section b×h (mm×mm)

(m)                              Single-span column                Multi-span column

6-8                              350×350                           350×500

8-10                             400×600                           400×600

10-12                            400×800                           400×800




                                                 45
                  Annex C       Notes of Wording for the Standard

The wordings used to express the degrees of strictness shall be dealt with in accordance with
the following statements of wordings:
C.0.1 Wordings used to express requirements that must be very strictly followed without any
deviation therefrom.
Wording in positive form to be used is "shall", and wording in negative form to be used is
"shall not".
C.0.2 Wordings used to express something shall be done in this way under normal conditions.
Wording in positive form to be used is "shall", and wording in negative form to be used is
"shall not".
C.0.3 Wordings used to express the action steps are allowed with possibilities for selection or
when the conditions are permissible it should be done first:
Wording in positive form to be used is "should" or "may", and wording in negative form to be
used is "should not".




                                              46

				
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