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Compaction Grouting In SAND

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					                          COMPACTION GROUTING IN SAND


Gehan E. Abdelrahman: Lecturer, Civil Eng. Dep., Faculty of Eng., Cairo University, Fayoum Branch.
Mahmoud S. Abdelbaki: Lecturer, Civil Eng. Dep., Faculty of Eng., Cairo University, Fayoum Branch.
Fatma A. Baligh: Professor, Civil Engineering Department, Faculty of Engineering, Helwan University.



ABSTRACT
Compaction grouting is a relatively new technique; it is defined as the injection of fluidized
materials into voids of the ground or spaces between the ground and adjacent structures, generally
through boreholes and under pressure. The main objective of this study is to produce the
Compaction Grouting using different procedure techniques, theories of design, and at the end, an
evaluation is presented. In Egypt, Compaction Grouting was first introduced in 1997, this case is
presented in this study. For many engineers, grouting is still considered an art rather than a
science. Its successful application requires a great deal of experience, thorough knowledge of
geotechnical conditions, and an awareness of equipment capabilities and limitations.


1. INTRODUCTION
The main objective of grouting is to produce a stronger, denser, and/or less permeable soil or
rock; it may also simply serve to fill voids which are otherwise inaccessible and may prevent
adequate stress transfer within the ground or from a structure to the ground, [1].
Grouting techniques are classified according to the method used to introduce the grout into the
ground. However, other criteria could be used to differentiate grouting methods, such as the type
of grout material injected, the typical application, the layout of injection points and the sequence
of construction. Distinguished by the mode of entry into the soil or rock, the basic categories of
grouting; penetration grouting (intrusion, permeation), displacement grouting, compaction
grouting (including slab-jacking), jet grouting (replacement), and special grouting applications and
techniques, including electro-grouting.
In compaction grouting a very stiff (one inch-slump) mortar is injected into loose soils, forming
grout bulbs which displace and densify the surrounding ground, without penetrating the soil pores.
With slightly more fluid grout, thick fissures rather than bulbs may form; this is sometimes referred


                                                     1
 to as squeeze grouting. Compaction grouting may be employed for lifting and leveling of heavy
structures, [2].

2. COMPARISION BETWEEN COMPACTION AND CONVENTIONAL GROUTING
It is important to distinguish between compaction grouting and penetration grouting. Penetration
grouting involves filling joints or fractures in rocks or pore spaces in soil with a fluid grout. The
intention is to reduce permeability, although in many cases strengthening is also desired and
achieved. In contrast, compaction grouting does not depend on the grout entering openings and
voids in the soil, although it may do so in large openings. It consists of intruding a mass of very
thick consistency grout into the soil, thus both displacing and compacting it. In contrast to
permeation (chemical) grouting, the influence of the grout extends well beyond the grout mass,
involving soil volumes up to 20 times the grout volume, which makes its use nearly always limited
to soils and soils of low compaction. (Compaction grouting is actually more effective in fine-
grained soils, formerly considered ungroutable.) Injecting an expanding bulb of highly viscous
grout with high internal friction into a compactable soil so that, acting as a radial hydraulic jack, it
can physically displace the soil particles and move them into a closer spacing, thus achieving
controlled densification.
Because of this basic difference in mechanism, the types of soils that can be improved by
compaction grouting are substantially different and often quite opposite of those for which
penetration grouting would apply. Also, because of this fundamental difference, equipment, grout
material, techniques of injection and grouting specifications differ substantially from those for
penetration grouting.


3. COMPACTION GROUTING AND ITS SUITABILITY FOR VARIOUS SOILS
Compaction grouting is most commonly used to stabilize the soil under residences and light
commercial buildings. However, it has also been extensively used to stabilize foundations of large
structures, including even bridges, culverts, and the ground under the tips of piles. All types of
soils can be improved by compaction grouting, but the effectiveness for a given amount of effort
will vary according to soil type and density. Although densification can be achieved in clean sands,
in practice, compaction grouting is seldom used in such deposits. Compaction grouting of
saturated clays is also less efficient than silts or solids of a heterogeneous composition and they are
not so commonly treated, [3].

                                                   2
 4. MECHANISM OF COMPACTION GROUTING
When a quantity of grout is injected into a compressible layer between two zones of competent
soil, the following effects have been noted, [4-6]:
   a) The grout pressure causes a complex system of radial and tangential stresses in the soil,
       which are greatest near the grout mass and decrease outward. For a given soil, the soil
       stress and maximum distance of influence will vary with the injection pressure.
   b) For a given pressure, the diameter of the grout column will vary not only with
       different relative compactions, but also for different soil types and moisture
       contents.
   c) As the pressure increases, the grout column will increase in diameter, effecting
       compaction to a greater distance. Close to the grout column, major displacement
       and shearing or plastic deformation of the soil will take place. At the same distance,
       where the stress is low in relation to the soil strength, the deformation will be
       largely elastic. In-between, a major zone of elastic and plastic deformation will
       occur.
   d) As the grout column increases in diameter, the compacted soil offers more and
       more resistance. The total upward pressure increases in proportion to the square of
       the diameter. Therefore, if pumping is continued, a pressure (grout column
       diameter) is ultimately reached at which the uplift pressure becomes large enough
       to cause upward movement of the ground surface. At this point, the pressure
       decreases and continued compaction diminishes.
   e) The total quantity injected will be a function of pumping rate; slower rates result in
       greater quantities.
   f) The degree of compaction achieved will be a function of the amount of grout
       injected (reduced by the amount of any ground surface displacement). The average
       increase in relative compaction as a percentage of any soil mass treated is given:

                                     100W         1          1
                             ∆RC =                         − 
                                      γ max V0 − (Vg − Vs ) V0 
                                                               
Which: ΔRC = change (increase) in relative compaction, W = weight of soil mass considered;
Vo = original volume of the soil mass; γ   max   = maximum density; Vg = volume of grout injection
and Vs = volume correction for any rise of the ground surface. Recently, Wong [7] established the


                                                   3
 basic factors which would affect the performance of compaction grouting. Compaction grouting
would cause three different modes of soil deformation as shown in Fig. (1).




               Figure 1: Modes of deformation of the soil mass (after Wong, 1996)


5. THEORY OF COMPACTION GROUTING
A simple theory evolved, based on a model that agrees with the observations of Graf [8], on
compaction grouting, which to a first-order approximation predicts the correct grouting pressures
for the process. Wong, [9] considered the simplest case Fig. (2) of a spherical grout mass of radius
"r", with its center at a distance "h" vertically below a horizontal free ground surface. Assuming
that the grout pipe has been firmly sealed in the surrounding ground of loose sand, the upper
limiting pressure will coincide with the onset of ground heave. From the observations of Graf [6],
it follows that in the limiting case a truncated cone of soil above the grout source will be inclined
at an angle, θ, of about 60o to the horizontal, which is equivalent to the application of the Mohr-
Coulomb failure criterion to any point along this conical surface. This is because the angle of
internal friction,φ, for a loose sand is usually about 30o, and the maximum and minimum principal
stresses should be along the vertical and horizontal directions respectively, thus giving θ = 45o + φ
/2, a value of about 60o. This too is in agreement with Graf's observations [8]. Wong, [9] has
further assumed that the grouting pressure is essentially uniform throughout the grout mass,
whose radius "r" will increase with the increase in grouting pressure. The maximum allowable
grouting pressure, Po ,at a certain equivalent radius of the grouted mass can then be obtained by
equating the upward force exerted by the grouted mass to the total weight of the truncated cone
of soil plus the downward shearing resistance (calculated from Mohr-Coulomb criterion) of soil
along the potential failure surface (see Fig. 2). This gives:

                                                   4
        Figure 2: Ground stress conditions under compaction grouting (after Wong, 1974)


                               2
                           D      D
                            r  + 3 r  tan θ + 3 tan θ
                                                       2

                                                         2(1 − sin φ ) cos(180 − θ + φ ) 
                   Po = γh                                  1 +                              
                                     3 tan 2 θ                         cos φ cos θ           

Where: γ = total soil bulk density.




                                                      5
           Figure 3: Maximum allowable grouting pressure under compaction grouting
                                        (after Wong, 1974)
It can be seen that design curves, such as those in Fig. (3), offer a very convenient means of
predicting the order of magnitude of the maximum allowable grouting pressure in actual
compaction grouting since the φ and D values are normally available. As for the diameter of the
grouted mass, 2r, this can be estimated by measuring the volume of grout that has been pumped
in, [6].
5.1 Recent Studies
Wong et al., [7] found that the mechanism for causing the conical shearing surface is quite
complicated since the friction between the cone and the surrounding soil is difficult to assess.
Assuming that at critical conditions the friction could be neglected, the conical failure conditions
illustrated in Fig. (2) would occur when:
U- W > 0                                                          (1)
U = π r2 Pc                                                       (2)
W = πγ [(D + k r)3 – k3 r3 ] / 3 k2                               (3)
In which: U: uplifting force, W: weight of the conical soil mass, Pc: cavity pressure, k: gradient of
the conical surface.



                                                 6
 It can be deduced from the inclinometer readings that in sandy materials the inclination of the
shearing surface is around 30o from the vertical and equivalent k value is about 1.7. These
observations agree with those reported by Graf, [6].
5.2 Effects of Foundation Load
In order to interpret the results of compaction grouting to control foundation settlements, column
load L should be included in equation (1) such that:
U- (W+L) > 0                                                       (4)
Re-arranging equation (2) to (4) gives critical depth:
D < r k [(3 / r k γ) (Pc – (L/ π r2)) +1)]1/3 – 1                  (5)
5.3 A New Theory and Rational Design
Schmertmann et al., [10] developed this theory, using shear enhancement along grout columns,
due to lateral stress and density increase, to support the soil above and between the grout
columns. Makura et al., [11] explained with section across treated area as shown in Fig. (4).




                   Figure 4: Section across treated area (after Makura et al., 1999)
Consider that high injections of low slump grout form a geometric pattern of columns each of a
height h. Each column helps to displace and compact the soil in an area s2 between adjacent
columns and increases the lateral pressure σh and soil friction τ at the column/ soil boundary. The
resultant density and stress increases result in a potential columns/soil shear force T and a top
bearing pressure R. By varying suitable combinations of column spacing s, height h and average
diameter d until the overburden soils can be verified. Any surcharge q generated additional ∆T and
∆R in the soil. The design analysis aims at achieving a certain factor of safety F, using only
effective forces and stresses. Depending on the critical conditions, total forces and stresses may
also be used. The weight requiring support is expressed according to following equation:
Fv ↓ = (γ z + q) s2                                              (6)


                                                    7
 The forces for supporting Fv↑, which consist of T and R plus ∆T and ∆R
T=τπ dh                                                         (7)
τ = σh tan φg                                                   (8)
where φg = soil/grout column friction angle
σh = [ Ko + 0.5(Kg – Ko)] (σv )                               (9)
Where Ko and Kg denote the earth pressure coefficients before and after grouting respectively
∆T = Ko q tan φg π d h                                          (10)
R = σv ∆ d2 /4                                                  (11)
(Where σv = grouting pressure at top of columns)
∆R = θ q π d2 /4                                                (12)
Where θ = stress concentration factor on top of columns (after Boussinesq theory)
The support for the imposed weight is given by
Fv↑ = T + ∆T + R + ∆R                                            (13)
The factor of safety is:
F = Fv ↑ / Fv↓ = (T + ∆T + R + ∆R) / ((γ z + q) s2)             (14)
This design concept provides a rational basis for the design of grouted soils that support the
overlying materials between and above the soil columns. The method is best suited for uniform
materials such as wad where near cylindrical shaped grout bulbs will be formed on grouting, [3].


6. GROUT MATERIALS
Most compaction grout work has been carried out using the portland cement-silty sand mix that
the Kochring mudjack is suited to handle, [6].
6.1 Classification of Grouting Materials
Two c1asses of grouting materials are generally recognized:
    1. Suspension (particulate)-type grouts (Binghamian fluids), which include soil, cement-lime,
        asphalt,…
    2. Solution (non-particulate)-type grouts (Newtonian fluids), which include a wide variety of
        chemicals.
Cambefort, [12] summarized the principal types of grouts as shown in table (1). Particulate grouts
may consist of cement-water, clay-water, cement-clay-water mixes, cement-bentonite-water with


                                                 8
 and without admixtures, and cement-sand with and without admixtures. In order that grouting
result is successful, it is evident that the injector has to choose the grout most suitable to the
problem (viscosity, setting time, strength).




                      Table 1: Principal types of grouts (after Cambefort,1987)
6.2 Basic Rheological Properties of Grouts
Rheology is the study of flowage of materials. The most important basic characteristics of grouts
are viscosity, stability, and setting time.
       6.2.1 Viscosity
        Turbulent flow is important as far as maintaining the stability of the grout during pumping
is concerned. Viscosity of a fluid can be measured directly or indirectly. A direct measurement is
obtained by a concentric-cylinder viscometer. On a construction site, viscosity of a grout can be
obtained by the Marsh cone.
        6.2.2 Stability
        A grout is referred to as stable, if its particles remain in suspension of solution until they
have reached the destination in the ground. The separation of solids from the liquid is referred to
as bleeding. An indication of the stability of a suspension can be gained from bleeding value that
can be determined by a simple laboratory test. It is the percentage of the height of the column of
sediment clear water found after the particles have settled, to the original sample height of the
suspension grout. In compaction grouting, bleeding is deliberately induce in grout to give it shear
strength by keeping the particles in place immediately after injection, [13].


        6.2.3 Setting Time




                                                  9
        Setting time is the time required for the grout to harden. Cement-based grouts normally
set within 4 to 24 hours, depending on the additives used, [14]. Bentonite grout does not develop
a stable gel without the assistance of additives such as cement or silicates. In normal circumstances
gel times of 45-90 minute give adequate time for mixing, pumping, and placement.
6.3 Engineering Properties of Grouts
Engineering properties of grouts include density, modulus of elasticity, and ultimate strength. The
strength of the grout has two aspects: strength of the raw grout and strength of the grouted mass,
[15]. The strength or stiffness of the raw gel can be measured by; needle penetration resistance
test, vane shear test, or unconfined compression test. Most research work dealing with engineering
properties concentrated on the grout properties instead of those of the grout formation.


7. GROUT INJECTION PLANNING
7.1 Grout Hole Layout
A compaction grouting densification program is carried out in a planned grid pattern of grout
pipes, injected in phases at closer and closer spacing. The pattern is either square, triangular or
shifted rows. Baker, [16] mentioned that the ideal distance between the grout pipes depends on
the soil conditions, maximum acceptable pumping pressure (related to overburden depth and
acceptable heave), and required density. Actual final grout pipe spacing varies from as close as
1.25 x 1.25 m square grids to as wide as 7.5 x 7.5 m square grids. Typical final grid spacing is
1.8 to 3 m. Initial grout holes are termed "primary holes" and are done on wide grid spacing.
After all primary holes are grouted in an area; "secondary" holes are located and grouted at the
centers of the primary grid squares. After completion of primary and secondary holes, "tertiary"
holes are located and grouted at the centers of the resulting primary- secondary squares. After
tertiary holes, the final grid size is one-half the width of the initial primary hole grid spacing.
Fig. (5), shows a typical layout plan and sequence.




                                                 10
Figure 5: (a) Soil cross section and sequences; (b) Layout plan of a square treatment point pattern
                                       (after Boulanger, 1995)
7.2 Grout Quantities
An initial estimate of the volume of required grout is made based on the anticipated necessary
change in density within the target treatment zone. The required grout quantities can be as low as
a few percent to as high as 20 % or more of the total target zone. This is represented by the mean
net grout take i.e., ratio of the "injected grout volume not resulting in surface heave" to the
"treatment zone volume". Determination of in-place density and approximate maximum density for
the target treatment soils will give an indication of the maximum practical net displacement
volume that can be expected from the compaction grouting efforts. Maximum relative density is
only useful for very clean sands. In classical foundation rehabilitation compaction grouting where
the goal is to stop on-going footing or floor slab settlements, grouting at a particular location
usually continues until pressure refusal or slight surface heave is noted, regardless of the grout
quantities involved In foundation densification work, the probable total grout quantities should be
predicted and the target grout volumes should be established and assigned in a rational way to the
primary, secondary and tertiary grout holes.
Larger target quantities are usually specified for the primary and secondary holes, with reduced
quantities anticipated for the tertiary holes. Boulanger et al., [17] suggested that the primary and
secondary grout holes might be limited to 1/3 of the total anticipated grout take each, and the
tertiary holes limited to not more than 1/4 of the total target grout take each. Such a target grout
quantity distribution is shown in table 2.



                                                 11
                                   Table 2 Grout quantity distribution
                     Hole Type               Grout Holes         Target Grout Take
                       Primary                    25%               1 x 33% = 33%
                      Secondary                   25%               1 x 33% = 33%
                       Tertiary                   50%               2 x 25% = 50%
                      All Holes                  100%                    116 %


    If all holes in the above example take the maximum target values, the total results in a maximum
    take of 116 %. Actual grout takes may vary considerably from the target grout takes.
    7.3 Injection Termination Criteria
    In practice, the target grout take criteria are usually coordinated with maximum pressure and
    heave criteria. Maximum injection pressures criteria are usually initially established using past
    experience rules-of-thumb, and then adjusted during early grouting stages at a specific site.
    Injection pressures have generally been set relative to:
•      The vertical overburden pressure existing along with other factors such as imposed loading and
    cementing in the ground.
•      The desire to cause surface heave.
•      Specific site feed back from the monitoring systems.


    Compaction grouting is to continue at each hole stage until one of the following criteria occurs:
       1. Target grout volume for the stage has been met.
       2. The maximum surge pressure or greater occurs consistently at the current stage.
       3. Maximum backpressure or greater occurs at the current stage.
       4. Casing is forced out of ground by back pressure.
       5. Surface heave caused by the current grouting stage exceeds a certain value or when
           cumulative heave of a point located within a certain distance of the grout hole exceeds a
           certain value. "Cumulative heave" is only that for the current grout hole.
       6. Grout breaks out around the casing perimeter.
       7. Grout breaks out elsewhere at ground level.
    The above injection criteria are project specific.


                                                         12
8. QUALITY CONTROL TESTS (SLUMP TEST)
In Egypt plate load tests and SPT and PMT are more in use. But in the case of jobs under
structures where blow count tests or any sounding tests, such as static cone penetrations can
not be performed, other sounding tests such as ultrasound and cross hole geophysical tests
should be performed. The importance of maximum penetration of grouts is reflected in field
control testing during injection. This tends to concentrate on consistent rheological properties
and mixture concentration. For particulate grout, testing at the pump (or preferably at the point
of injection) is primarily in the form of checks on apparent viscosity (shear strength and plastic
viscosity). The most common tests are empirical and as such must be performed precisely
according to the test instructions. In the UK the Concrete flow trough measures the distance
traveled by a standard height from a conical container along a horizontal trough. Grouts with
identical apparent viscosities will travel consistently to the same distance. United States practice
is to use a Marsh cone, timing the efflux of a standard grout quantity from a standard cone.
Variations in mixing time or agglomerations of particles affect the results and consistent mixing
control can thus be assured. In hot climates temperatures can be high enough to affect the result
and adjustments must be made to the mix to achieve consistent properties at injection. Density
checks in a mud balance confirm concentration.


9. APPLICATION EXAMPLES
Compaction grouting has been undertaken to solve two basic problems, settlement prevention and
settlement correction. Ground improvement by compaction grouting has been commonly
employed to prepare the ground in readiness for the application of heavy or highly variable loaded
foundations or to eliminate possible weather zones beneath proposed foundations. Foundation
remedial works can also be achieved by controlled ground displacement with compaction grout
bulbs as shown in Fig. (6, a, b).




                                                  13
            Figure 6: (a) Ground improvement; (b) Foundation remedial works by compaction
                                  grouting (after Crockford, 1996).
In the case of pile supported structures, the soil underlying the pile tips can be densified by grout
injection, when the problem has been determined as bearing failure. Where a lack of friction is the
main deficiency, grout injection is often done starting at the surface and extending to underlying
competent soil or rock, Fig (7, a, b).




       Figure 7: (a) Compaction grouting near piles; (b) To increase friction(after Warner, 1982)
The technique has also been used to compensate for lost ground in soft ground tunneling. In such
cases, one or more lines of grout casing are placed longitudinally over the tunnel, to an elevation
1.8 to 2.4 m above its crown. As the tunnel shield passes, an injection is made, Fig. (8, a, b),
replacing any soil lost by the tunneling disturbance or in the shield tail void as it occurs reducing
surface settlements.




    Figure 8: (a) Grouting around pipe or culvert; (b) Grouting over tunnel(afterWarner,1982)

                                                 14
 10. COMPACTION GROUTING APPLICATIONS IN EGYPT
Compaction grouting was first introduced in 1997. Only one project was carried out under that
name but adopting a technique modified from that described above. That case and another close
one are presented below:
Golden Pyramid Plaza-Heliopolis Project
This job was carried out for the construction of a hotel and shopping center over an area of
126,000 m2 at El-Nasr City. Piles were first suggested for the foundation. But isolated footings
were preferred with soil improvement to increase the bearing capacity and reduce differential
settlements and absolute settlements. The method chosen for site improvement was called
“Reinforced Computerized Compaction Grouting Method” or “Reinforced Compaction Grouting
Columns” (RCGC).
1. Site Conditions:
The site was medium to fine sand, poorly graded, slightly cemented with traces of silt or clay. This
soil with different combinations extended to a depth 45 m. There were no signs of ground water
over that depth. The average dry density was 1.7 t/m3. Four types of preliminary tests were
performed; pressuremeter tests, collapsibility test, two load tests, and five pull out tests.
2. Grout Mix Properties:
•   The mix per m3 was: 1200 kg of sulfate resistant cement (SRC) and 600 kg water (i.e.
    Water/Cement = 0.5). The grout density ranged between 1.79 and 1.87 t/m3 and the viscosity
    ranged from 40 to 45 sec/ lit.
•   Compressive strength at 3 days, 7 days and 28 days had an average of 165, 227 and 357
    kg/cm2, respectively.
•   Young's modulus of elasticity was increased by 50%
3. Acceptance Criteria
Acceptance criteria were both bearing and settlement criteria:
•   Net safe bearing capacity of 7 or 8 kg/cm2.
•   Maximum allowable settlement of 12 mm.
•   A differential settlement of 0.05% of the distance between loads.




                                                   15
11. EVALUATION OF COMPACTION GROUTING METHOD
Compaction grouting has some major advantages but also some distinct limitations.
Advantages
•   Minimum disturbance to the structure and the surrounding ground during repair:
•   Minimum risk during construction
•   Supports all portions of a structure
•   Loose or problem soil can be treated irrespective of their depth or thickness
•   Compaction grouting can be combined with other ground modification techniques to increase
    in density, shear strength and bearing capacity of the soil.
•   High production rates, 10 times faster than convention grouting.
•   No harmful vibrations to nearby structures/ utilities.
•   Significant reduction in soil permeability greater economy. Although compaction grouting is
    expensive, it frequently is the most economical method.
•   Increasing the liquefaction resistance of layers of loose granular soils at depth.
•   Re-compacts soils within vicinity of the problem.
Disadvantages
Disadvantages include the need for more technical understanding of the treatment mechanisms,
and empirical guidelines to predict treatment effectiveness.
•   Relative ineffectiveness in stabilizing near-surface soils: where the overlying restraint is small.
•   Prohibitive cost for some structures if the faulty soil is excessively deep.
•   Grouting adjacent to unsupported slopes may be ineffective.
•   Difficulty of analyzing results.
•   Not valid in decomposable material.
•   Danger of filling underground pipes with grout.
•   Questionable effectiveness in saturated clays.
•   It is still a relatively more expensive option for most conventional ground densification
    treatments.




                                                   16
 14. CONCLUTIONS
•   As the effectiveness of the grout injection depends greatly on the properties and condition of
    the grout, it is of major importance to establish how to determine the suitable grout. Until
    now, the appropriate range of particle size distribution, slump value, has been selected based
    on experience.
•   A more effective method of determining a grout that will give grouting effectiveness and
    workability as well as the establishment of monitoring methods, need to be considered.
•   As for the fracturing risk, research today is not sufficiently advanced to directly predict the
    behavior of a grout in connection with soil.
•   More research is still needed to give a range or a critical shear strength for which sand
    blocking would occur.


15. REFERENCES
1. Hausmann, M.R. (1990). Text book. "Engineering Principles of Ground Modifications."
    McGraw-Hill Publishing Company.
2. King, J.C. and Bindoff, E.W. (1982). "Lifting and Leveling of Heavy Concrete Structures."
    Proc. Conf. Grouting in Geotech. Eng., New Orleans, Louisiana, United States, Published by
    ASCE, pp. 722-737. Quoted from Ref. 1
3. Brown, D.R. and Warner, J. (1973) "Compaction Grouting." Journal of S.M.F.E. Division,
    ASCE, Vol. 99, No. 8, pp.589-601.
4. Mitchell, J.F. (1970). "In-Place Treatment of Foundation Soils." Proc. ASCE Jour. Of SMFE,
    87 (SM-1), paper 7035, pp.73-110.
5. Warner, J. (1972) "Compaction Grouting Rheology vs. Effectiveness." ASCE Conference on
    Grouting, Soil Improvement and Geosynthetics, ASCE Geotechnical Special Publication
    No.30, pp.229-239.
6. Graf, E. D. (1969) "Compaction Grouting Technique." Journal of Soil Mechanics and
    Foundation Division, ASCE, Vol. 95.
7. Wong, L.W., Shau, M.C. and Chen, H.T. (1996)."Compaction Grouting for Correcting
    Building Settlement." Proceedings of the 2nd Int. Conf. on Ground Improvement Geosystems.
    Tokyo, Vol. 1, pp.231-236.




                                                   17
 8. Graf, E. D. (1984) Personal communication concerning Kaiser Hospital Site Improvement
   Grouting. Quoted from Ref. [17].
9. Wong, L.W. (1974) "Discussion of Compaction Grouting." By Douglas R. Brown and James
   Warner, Journal of Soil Mechanics and Foundation Division, ASCE, Vol. 100, pp.556-559.
10. Schmertmann J. H. and Henry (1992). "A Design Theory for Compaction Grouting." Grouting
   Soil Improvement and Geot-Synthetics, RH Borden ed. , ASCE, Geotechnical Special
   Publication No. 30 pp. 275-287. Quoted from Ref. [13].
11. Makura, S. and Schulze A. (1999). "Compaction Grouting-Application on Dolomite".
   Proceedings of the 12th African Regional Conf. on Geotechnics for Developing Africa.
   Durban, South Africa. Oct. 1999. pp. 571-577.
12. Cambefort, H. (1987). "Grouts and Grouting", Chapter (32) in Bell, F.G. (ed.): Ground
   Engineer's Reference Book. Quoted from Ref. [1]
13. Henry, F.D.C. (1985). Text book. "The Design and Construction of Engineering Foundation".
   Chapman and Hill.
14. Moseley, M.P. (1993). "Ground Improvement." Text Book. Published by Blackie Academic &
   Professional, an imprint of Chapman & Hall Wester Cleddens Road, Bishopbriggs, Glasgow,
   G 64 NZ.
15. Arvind V. Shroff and Dhanajay L. Shah (1993). "Grouting Technology in Tunneling and Dam
   Construction". Text book. A.A. Balkima/ Rotterdam/ Brookfield. (ch. 10)
16. Baker, W.H. (1985). "Embankment Foundation Densification by Compaction Grouting."
   Proceedings of the Session Sponsored by the Geotechnical Engineering, Div. of the ASCE on
   Issues in Dam Grouting, Denver, Colorado.
17. Boulanger, R.W. and R.F. Hayden (1995). "Aspects of Compaction Grouting of Liquefiable
    Soil." Journal of Geotech. and Geoenviromental Engineering, Vol. 121, No. 12, pp. 844-855.




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                                                                                                                   ‫ﻣﻠﺨﺺ ﺍﻟﺒﺤﺚ‬

    ‫ﻣﻔﺼﻞ ﻟﻜﻴﻔﻴﺔ ﺍﺳﺘﺨﺪﺍﻡ ﻫﺬﺓ ﻳﻘﺪﻡ ﻫﺬﺍ ﺍﻟﺒﺤﺚ ﺷﺮﺣﺎ ﻋﺎﻣﺎ ﻋﻦ ﻋﻤﻠﻴﺔ ﺍﻟﺪﻣﻚ ﺑﺎﳊﻘﻦ ﻟﻠﺘﺮﺑﺔ ﺍﻟﺮﻣﻠﻴﺔ ﻟﺰﻳﺎﺩﺓ ﻗﻮﺓ ﲢﻤﻞ ﺍﻟﺘﺮﺑﺔ. ﻭ ﻗﺪ ﺃﺣﺘﻮﻯ ﻋﻠﻰ ﺷﺮﺡ‬

      ‫ﺍﻟﻄﺮﻳﻘﺔ ﺍﳋﺎﺻﺔ ﺑﺘﺤﺴﲔ ﻣﻘﺎﻭﻣﺔ ﺍﻟﺘﺮﺑﺔ ﻣﻊ ﺑﻴﺎﻥ ﲨﻴﻊ ﻣﺮﺍﺣﻞ ﺍﻟﺘﻨﻔﻴﺬ ﻭ ﺍﻟﺘﺮﻛﻴﺰ ﻋﻠﻰ ﺍﳌﺸﺎﻛﻞ ﺍﻟﻮﺛﻴﻘﺔ ﺍﻟﺼﻠﺔ ﲟﻮﺿﻮﻉ ﺍﻟﺒﺤﺚ. ﻛﻤﺎ ﻳﻘﺪﻡ ﺃﻳﻀﺎ ﻃﺮﻕ‬

‫ﺍﻟﺘﺼﻤﻴﻢ ﺍﳌﺨﺘﻠﻔﺔ ﻛﻤﺎ ﻳﺴﺘﻌﺮﺽ ﺃﻳﻀﺎ ﺍﻷﺳﺘﺨﺪﺍﻣﺎﺕ ﺍﳌﺨﺘﻠﻔﺔ ﻭ ﳑﻴﺰﺍﺕ ﻭ ﻋﻴﻮﺏ ﻫﺬﺓ ﺍﻟﻄﺮﻳﻘﺔ. ﻭ ﺣﻴﺚ ﺃﻥ ﻃﺮﻳﻘﺔ ﺍﻟﺪﻣﻚ ﺑﺎﳊﻘﻦ ﻣﻦ ﺍﻟﻄﺮﻕ ﺍﳊﺪﻳﺜﺔ ﻓﻘﺪ‬

                                             ‫ﺑﺪﺃ ﺃﺳﺘﺨﺪﺍﻣﻬﺎ ﰱ ﻣﺼﺮ ﻣﻨﺬ ﻋﺎﻡ ٧٩٩١ ﰱ ﻣﺸﺮﻭﻋﲔ ﻭ ﻗﺪ ﰎ ﺃﺳﺘﻌﺮﺍﺽ ﺃﺣﺪﳘﺎ ﰱ ﻫﺬﺍ ﺍﻟﺒﺤﺚ.‬




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