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Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Figure 6. The relationship between modulus and shear strain level of
soft and stiff Bangkok clay (Teparaksa, 1999b).
Figure 7. Deformed mesh of FEM analysis at the final stage excavation
at -15.6m.
The measurement of the lateral diaphragm wall movement at
all steps of excavation and basement floor casting at
inclinometer no. I-3 next to Tewavej Palace is shown in Fig. 8
together with the predicted maximum envelope of diaphragm
wall movement estimated by FEM.
It can be seen that the predicted wall movement by FEM
agrees well with field performance. The tiltmeter measured at
the Tewavej Palace is also less than the trigger level. The
basement construction of the new head office of Bank of
Thailand was completed without any disturbance to both
Bangkhunphrom Palace and Tewavej Palace.
Figure 8. The inclinometer I-3 monitoring results with the predicted
maximum movement by FEM analysis.
7 CONCLUSIONS
The basement of 15.6 m. deep excavation was constructed at the
new head office of Bank of Thailand. The deep basement
consists of 5 basement floors at -1.20 m., -4.70 m., -7.70 m., -
10.70 m. and -13.70 m. depth. The basement constructed area is
closed to two palaces; Bangkhunphrom Palace and Tewavej
Palace, which are the historical buildings and also located close
to the Chao Phraya river bank. The top down construction
method was used for basement construction. The prediction of
diaphragm wall movement and its effect to the palaces were
carried out by FEM analysis. The instrumentation was installed
in D-wall, ground surface and the palaces in order to measure
the wall behavior and their effect. The lateral movement of D-
wall by means of inclinometer at all stages of construction is
compared with FEM prediction. The FEM prediction agrees
well with measured values. The deep basement was completed
without any disturbance to both palaces.
8 REFERENCES
Mair R.J. 1993. Unwin Memorial Lecture 1992 Developments in
geotechnical engineering research: application totunnels and deep
excavations.
Proceeding of the Institution of Civil Engineers. Civil
Engineering.
Vol. 97, No. 1, 27-41.
Teparaksa W. 1992. Deep basement construction in Bangkok soft clay
by sheet pile braced cut system. Journal of Engineering of Thailand.
97-106. (in Thai)
Teparaksa W., Thassananipan N. And Tanseng P. 1999a. Analysis of
lateral movement for deep braced excavation in Bangkok subsoil.
Civil and Environmental Engineering Conference-New Frontier &
Challengers, AIT, Bangkok.
Teparaksa W. 1999b. Principal and application of instrument for the
first MRTA Subway Project in Bangkok.
The 5
th
Int. Symposium on
Field Measurement in Geomechanics.
Singapore. 411-416.
Teparaksa W. 2007. Deformation of subway tunnel induced by deep
basement excavation in MRT Protection Zone, Bangkok.
Theme
Speaker. 13
th
Asian Regional Conference in Soil Mechanics and
Geotechnical Engineering
, Decrmber, Kalkate, India.
