Discussions on elastic parameters of soil for land subsidence caused by decompression of confined aquifer in deep excavation

The relationships among the soil shear modulusobtained by oedometer tests, by pumping tests and the initial shear modulusof hardening soil small (HSS) model for soft soil under sensitive circumstance in Shanghai and Tianjin are studied. The HSS model is used to fit the relationship between shear modulus ratio and shear strain. It is found that the soil strain caused by excavation dewatering under sensitive circumstance is about 0.1%~0.5%. The shear modulus of can be adopted to estimate soil deformation. Taking the deep foundation pit dewatering projects of Hangzhong Road Station of Shanghai Metro Line No. 10 and Pengyuepu Pumping Station as examples, the deformation calculated by adopting the elastic modulus determined by the proposed method is close to that by adopting the parameter obtained from in-suit pumping tests, and thus the rationality of the proposed method is verified.