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| DEFORMATION CHARACTERISTICS ANALYSIS OF DIAPHRAGM WALL FOR FOUNDATION PIT SUPPORT IN SOFT SOIL |
| LIU Nianwu1，2，GONG Xiaonan1，2，LOU Chunhui1，2 |
(1. Research Center of Coastal and Urban Geotechnical Engineering，Zhejiang University，Hangzhou，Zhejiang 310058，China；
2. Key Laboratory of Soft Soils and Geoenvironmental Engineering，Zhejiang University，Hangzhou，Zhejiang 310058，China) |
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Abstract The deformation characteristic of diaphragm wall in combination with brace differs from the flexible support structure because of its higher system stiffness. In order to investigate the deformation characteristics of the diaphragm walls，a series of field data including diaphragm wall deflections，soil settlements，axial forces of supports were obtained. Based on the field data，the following major findings were obtained. The location of the maximum lateral displacement occurs between He－3 and He+1 m，the values of dhm/He scatter but have a tendency to decrease with the increase of system stiffness. The settlement behind the diaphragm wall increases first and then decreases as the distance from the diaphragm wall increases. The settlement reaches the maximum when the value of x/He is 0.67. As the value of L/He(L is the distance of the measuring point to the excavation end along the longitudinal direction) increases，the plane strain ratio(PSR) increases first and then maintains stable. The value of PSR is 0.71 in the corner of the excavation，and reaches 1.0 as the value of PSR approaches 3.0. The axial forces of concrete support of the first and second support of rock-socketed diaphragm decrease with the installation of the third and fourth steel pipe support and increase with the dismantlement of the third and fourth steel pipe support.
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Received: 31 May 2013
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2014, Vol. 33 
