30 Years of NISHIMATSU Tunnel Construction Experience Record

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					International Symposium on Underground Excavation and Tunnelling
2-4 February 2006, Bangkok, Thailand




30 Years of NISHIMATSU Tunnel Construction Experiences in
Bangkok and the Surrounding Metropolitan Region

Somsak Wongwishakorn1, Nopporn Rattanachayabun1, Sirisin Janrungautai1
1
    Nishimatsu Construction Co., Ltd., Bangkok, Thailand



ABSTRACT

NISHIMATSU CONSTRUCTION Co., Ltd. has been constructing tunnels and associated structures
within the Bangkok Metropolitan area since 1976. During this period NISHIMATSU has completed a
significant number of projects for many clients employing a wide range of tunneling and associated
works. Some of NISHIMATSU’s major clients being: Metropolitan Waterworks Authority (MWA),
Bangkok Metropolitan Administration (BMA), Pollution Control Department (PCD) and Mass Rapid
Transit Authority of Thailand (MRTA). Since 1976 the utilization of tunnels and tunnel construction
techniques in Bangkok has developed rapidly and NISHIMATSU has embraced such technological
changes permitting the successful completion of many challenging projects. Due to this extensive
experience NISHIMATSU lays claim to being the leading tunneling contractor within the region,
having completed more kilometers of tunnel construction than any other contractor. The intent of this
paper is to illustrate NISHIMATSU’s extensive tunneling experience in the Bangkok region with an
overview of some of the various tunnel projects completed and techniques employed since 1976.


1. INTRODUCTION

In the past many questions had arisen regarding the possibility of tunnel construction in soft ground,
not only in Bangkok, but worldwide – with such concerns appearing justified by the many difficulties
encountered during the construction of the Bangkok Municipal Administration Rama IV Road
Drainage Tunnel. However, due to increasing demand for tunnel usage, especially for potable water
transmission networks, technologies were developed to tackle such difficulties and in 1976 the very
first deep level, non cut-and-cover, tunnel in Bangkok was initiated by the Metropolitan Waterworks
Authority to supply potable water from Bang Khen Water Treatment Plant to the Thonburi area, with
NISHIMATSU as the tunnel construction contractor.
         Since 1976 tunnel construction techniques in Bangkok, as well as tunneling machine
technology has developed considerably, as summarized in Figure 1.
         From this first tunnel in 1976 to today, NISHIMATSU has completed a number of tunnel
projects that can be classified according to the tunnel’s application as follows:
     1) Potable Water Transmission Tunnels.
         Client: Metropolitan Waterworks Authority (MWA).
     2) Wastewater Transmission Tunnels.
         Client: Bangkok Metropolitan Administration (BMA) and Pollution Control Department (PCD)
     3) Subway Tunnels.
         Client: Mass Rapid Transit Authority of Thailand (MRTA)
     4) Water Drainage Tunnel for Flood Protection.
         Client: Bangkok Metropolitan Administration (BMA).




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Figure 1. Development of tunnel construction in Bangkok since 1976

       A summary of NISHIMATSU’s tunnel construction experience in Bangkok and the
surrounding Metropolitan region is shown in Figure 2 and described in the following sections.


2. POTABLE WATER TRANSMISSION TUNNEL PROJECTS

Since 1976 the MWA has commissioned an extensive and ongoing network of potable water
transmission tunnels; completing to date, approximately 96 km of tunnels, with diameters ranging
from φ3400 ID to φ2000 ID and let under 17 separate Contracts. NISHIMATSU were engaged for 7 of
these Contracts, completing approximately 24 km of the tunneling network. Details of these Contracts
are illustrated in the following sections.




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Figure 2. NISHIMATSU tunnel construction works

2.1 MWA Water Transmission Tunnel Project Stage 1

The MWA Water Transmission Tunnel
Project Stage 1 was constructed from
1976 to 1979 and comprised 3 contracts
entitled: G-TN-1A, G-TN-2 and G-TN-
4BR, all of which were carried out by
NISHIMATSU. The outline of the tunnel
route is shown in Figure 3.
         Contract numbers G-TN-2 and G-
TN-1A had a combined tunnel length 10.2
km with an outside shield diameter of
φ4560 and a final inside diameter of
φ3400. The original working plan for
these two contracts envisaged three sets of
semi-mechanical shields (blind type, as
shown in Figure 4) and two temporary
working shafts to be provided between the
Surge Tower and the Phahonyothin Valve
Chamber. Two shield machines were to
be launched from working shaft No.1 in
opposing directions; one towards the
Surge tower and the other towards
working shaft No.2. Working shaft No.1
was located approximately 4.0 km from
the Surge Tower and 3.3 km from shaft
No.2. The third shield machine was
planned to excavate from working shaft
                                              Figure 3. MWA Water Transmission Tunnel Project
No.2 to the Phahonyothin Valve Chamber,
                                              Stage 1
a distance of approximately 2.9 km.




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        Upon works commence-
ment extremely poor soil
conditions, loose brown fine
sand     with     water,    were
encountered in the tunnel drive
from working shaft No.1 to the
Surge Tower (refer soil profile in
Figure 5) and it became
necessary to modify the shield
machine to a slurry type,
consequently delaying the works
schedule. To complete these
modification works an additional
working shaft (No.3) was
constructed 1 km from the Surge
Tower. The soil conditions along
tunnel route from working shaft
No.1 to the Phahonyothin Valve
Chamber were as expected, stiff
to very stiff clays, allowing an     Figure 4. Semi-mechanical shield (blind type) used in the MWA
average tunneling progress rate      Water Transmission Tunnel Project Stage 1
of 8 m/day.




Figure 5. Soil profile along the MWA Water Transmission Tunnel Project Stage 1




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         Contract G-TN-4BR had a tunnel length of 3.7 km, with an outside shield diameter of φ3000
and a final inside diameter of φ2000. Two sets of semi-mechanical shields (blind type) and one
temporary shaft were used. The working shaft was located at the center of contract (Wongwien Yai
Circle) and the shield machines were launched from this shaft in opposing directions, one towards the
Tha Phra Riser Structure, and the other towards Ladya. No difficulties were encountered in these
drives thus allowing the shield machines to maintain an average tunneling progress rate of 8 m/day.

2.2 MWA Water Transmission Tunnel Project Stage 2

Under the stage 2 project NISHIMATSU
were awarded contract No. G-TN-5C which
had a construction period of 2 years, from
1981 to 1983. The total tunnel length was 2.9
km, consisting of; 2.66 km of outside
diameter φ3380 main tunnel, using a semi
mechanical shield (backhoe type, as shown in
Figure 6); and 0.24 km of outside diameter
φ2866 branch tunnel, constructed with a
conventional (manual) shield machine. For
the main tunnel two shield machines were
launched from a temporary working shaft.
One drive was along the Rama IV road to
Yannawa Valve Chamber and the second
drive was in the opposite direction along the
Rama IV road to the Klong Toey Valve
Chamber at Soi Sukhumvit 40. The average
tunneling progress rate was 9 m/day. For
branch tunnel excavation was from the Riser
                                                Figure 6. Semi-mechanical shield (backhoe type)
Structure in Soi Ban Kluay Tai to Klong
                                                used in the MWA Water Transmission Tunnel
Toey Valve Chamber, maintaining an
                                                Project Stage 2
average tunneling progress rate of 2.5 m/day.

2.3 MWA Water Transmission Tunnel Project Stage 3

Under the stage 3 project NISHIMATSU were awarded contract No. G-TN-6. The construction period
was from 1990 to 1991. The tunnel length was 2.2 km with an outside shield diameter of φ2780 and a
final inside diameter of φ2000. The tunneling was carried out using a semi-mechanical backhoe type
shield machine from the Ratchada Suthisarn Drop Structure to the Phahonyothin Riser Structure at the
Phahonyothin Pump Station. The soil conditions encountered along the tunnel route were stiff and
brown silty clays. The average tunneling progress was 10 m/day.

2.4 MWA Water Transmission Tunnel Project Stage 4

Under the stage 4 project NISHIMATSU were awarded two contracts: No.G-MC-7A and G-TN-7.
The construction period for these contracts was from 2001 to 2003. In contract G-MC-7A, the tunnel
length was 6.7 km with an inside diameter of φ3776 for the primary lining and φ3400 for the
secondary lining. In contract G-TN-7, the tunnel length was 2.4 km with an inside diameter of φ2900
for the primary lining and φ2500 for the secondary lining. Two EPB shield machines, φ4206 OD, (as
shown in Figure 7) were provided for contract G-MC-7A and one EPB shield machine, φ3330 OD,
was provided for contract G-TN-7. The average tunneling progress was 15.6 m/day in contract G-MC-
7A and 12 m/day in contract G-TN-7.




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Figure 7. EPB shield machine used in the MWA Water Transmission Tunnel Project Stage 4


3. WASTEWATER TRANSMISSION TUNNEL PROJECT

3.1 BMA Wastewater Transmission Tunnel Project Stage 1

NISHIMATSU was awarded the tunneling contract for the main water collection system tunnels by
NOSS consortium, the main contractor for the BMA Wastewater Treatment Project Stage 1. The water
collection system was planned to be constructed using shield machines for water gravity flow tunnels
of various sizes and elevations. Details of the tunnel system layout and soil conditions are shown in
Figure 8 and Figure 9.




Figure 8. BMA Wastewater Transmission Tunnel Project Stage 1



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Figure 9. Soil profile along the BMA Wastewater Transmission Tunnel Project Stage 1

         The works required three sizes of tunnel, φ3200, φ2500 and φ1700 ID to be driven in soft,
medium and stiff clays under roads and also under canals. The construction period was from 1994 to
1997. Prior to this project, EPB shield machines had never been used for tunneling in Bangkok,
NISHIMATSU was the first company to select and use EPB shield machine for tunneling in Bangkok
soils.
         For the φ3200 ID tunnel an
EPB shield machine with a φ3730 OD
(as shown in Figure 10) was provided.
This tunnel was excavated for 4.1 km
in stiff clay at an elevation of 20 m,
maintaining an average tunneling
progress rate of 12 m/day.
         For the φ2500 ID tunnel two
EPB shield machines with a φ2980 OD
were used to complete a total driven
length of 5.8 km. This tunnel was
excavated in soft and medium clays at
elevations of 19 and 11 m, maintaining
an average tunneling progress rate of
12 m/day.
         For the φ1700 ID tunnel an
EPB shield machine with a φ2120 OD
was used. This tunnel had a length of
2.1 km and was excavated in soft and       Figure 10. EPB shield machine used in the BMA
medium clays at an elevation of 10 m       Wastewater Tunnel Project Stage 1
and an average tunneling rate of 11
m/day.




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3.2 PCD Outfall Tunnel for Samut Prakarn Wastewater Project SC-41

NISHIMATSU was subcontracted by Italian-Thai Development Public Company Ltd. (ITD) to
construct the Outfall Tunnel from the On-shore Treatment Plant to the Outfall Shaft in the sea. This
tunnel was constructed under the seabed for the discharge of treated water from the Wastewater
Treatment Plant into the sea. Main contract details are:
    - The construction period was from 2000 to 2001;
    - The tunnel length was 2.6 km with a finished φ2600 ID;
    - Driving was carried out using an EPB shield machine with a φ3080 OD;
    - The average tunneling progress rate was 14.5 m/day.


4. SUBWAY TUNNEL PROJECT

NISHIMATSU was a partner in the ION Joint Venture, which was awarded the North Contract of
MRT Chaloem Ratchamongkhon Line (Blue Line) Civil Works by the MRTA. The scope of
NISHIMATSU works allocated from the ION Joint Venture is described as follows:
   1) Three underground stations along Ratchadaphisek Road consisting of:
         - Thailand Cultural Centre Station (S12);
         - Huai Khwang Station (S13); and
         - Sutthisan Station (S14).
   2) Twin tunnels from Rama 9 Station to Ratchadaphisek Station (S15);
   3) The depot approach tunnel constructed:
         - Part by an EPB shield machine; and
         - Part by diaphragm wall cut and cover construction.
   4) Two underpasses for vehicles at Station S13 and S14; and
   5) Three intervention shafts (IVS);
         - IVS1 between Rama 9 Station and Station S12;
         - IVS2 between Station S12 and Station S13; and
         - IVS3 between Station S13 and Station S14.
      The outline of the tunnel route and associated station works is shown in Figure 11.




Figure 11. MRTA Initial Subway Project



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        The     construction
period was from 1999 to
2001. The total combined
tunnel length was 8.75 km
with a φ5700 ID. Tunnel
driving was completed by
two EPB shield machines
with a φ6430 OD (as shown
in Figure 12). The tunnel
was excavated through stiff
clays and sand layers, as
shown in Figure 13. The
tunnel was excavated in stiff
clay and sand layer as
shown in Figure 13. The
average tunneling progress
rate was 9.5 m/day.             Figure 12. EPS shield machine used in the MRTA Subway Tunnel
                                Project




Figure 13. Soil profile along the MRTA Subway Tunnel Project


5. WATER DRAINAGE TUNNEL PROJECT FOR FLOOD PROTECTION

NISHIMATSU and ITD, as the IN Joint Venture, were awarded a flooding protection tunnel contract
by the BMA. This contract commenced in 2003 and now is still under construction. It consists of the
following works:
- An Intake Structure at Klong Ladprao and an Outfall Structure at Prakanong linked by the 5.2 km
    flood protection tunnel passing under Klong San Saeb, Klong Ton and Sukhumvit Road;
- A Pumping Station at Prakanong with a pumping capacity of 60 m3/s;
- The tunnel drive is being undertaken by an EPB shield machine with a φ5700 OD and a φ5000 ID;
- The soil conditions encountered being fine sands and dense to very dense sands.




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6. CONCLUSIONS

NISHIMATSU CONSTRUCTION Co., Ltd. lays claim to be the leading, and most experienced,
tunneling contractor in Bangkok and its surrounding Metropolitan region, with an impressive track
record in the many forms of tunnel construction completed in the area to date.
        The benchmarks set by NISHIMATSU for tunneling in Bangkok are as follows:
    1) Constructed the first tunnel in Bangkok utilizing a tunneling machine (1976 MWA Stage 1);
    2) The first company to use an EPB shield machine (1994 BMA Wastewater Stage 1);
    3) The first company to succeed in MWA Tunnel Rehabilitation (10.3 km);
    4) Completed the smallest shield tunneling drive: φ1700 ID (BMA Wastewater Stage 1);
    5) Carried out the sharpest shield tunneling curve: radius of 25 m (BMA Wastewater Stage 1);
    6) Completed the widest variety of shield tunneling projects (MWA, BMA, PCD and MRTA);
    7) Constructed more kilometers of tunnel than any other contractor: length 47 km (see Figure 14).




Figure 14. Status of shield tunneling activities in Bangkok since 1976

         During the last 30 years of tunnel construction in Bangkok and the surrounding Metropolitan
region, NISHIMATSU has encountered a wide variety of construction difficulties, all of which have
been successfully overcome. The introduction of new tunneling technologies and techniques by
NISHIMATSU has brought improved construction rates, and safer and better working conditions to
tunnel construction in Bangkok. Since the successful introduction of the EPB shield machine in the
Bangkok Wastewater Stage 1 Project in 1994-1997 by NISHIMATSU, the use of mechanical shield
construction with compressed air has become redundant and the specification of EPB shield tunneling
has become the preferred technique for tunnel construction e.g. MRTA, BMA, MWA and MEA
tunnels.
         Recently, local contractors have begun to enter into the Bangkok tunneling construction arena,
aided by the improvements in tunneling technologies and providing increased competition in the
market. However, it must be remembered that the difference in specified workmanship and quality
between, for example a Water Transmission Tunnel and a Mass Rapid Transit Tunnel, is very
significant. Consequently the consideration of a Contractor’s experience is still a necessary factor for
tunnel project qualification, especially for projects requiring the expeditious construction of high
quality tunnels.



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