Three Dimensional Performance Observed in an Irregular Deep Excavation in Shanghai Soft Clay

Pudong first excavation region of Shanghai South Xizang Road River-crossing Tunnel, which is the transportation hub of 2010 Shanghai World Expo, is irregular shaped and located in soft clay. Diaphragm wall deflection, ground surface settlement and strut axial force during excavation have been monitored. The results show that except general recognized factors, such as excavation depth and width, wall stiffness, strut spacing, and soil characteristics, the joint angel of two adjacent diaphragm walls also has a significant impact on diaphragm wall deflection and ground surface settlement of irregular shaped deep excavation; Three dimensional effect and corner effect in the researched irregular excavation can’t be neglected.