Numerical analysis of effect of friction between diaphragm wall and soil on braced excavation

A plane strain finite element model was established to investigate the effect of friction between diaphragm wall and soil on braced excavation. The behavior of interface between diaphragm wall and soil was simulated with the interface model of ABAQUS. Parametric studies were conducted with different diaphragm wall external friction angles delta. The results show that deflection of diaphragm wall and ground surface settlement decrease with the decrease of delta. However, the reduction effect on diaphragm wall deflection is the most significant at the depth where the maximum wall deflection occurs and can be neglected at the wall base. The ratio between wall deep inward component and wall cantilever component reaches its peak value 2.7 when delta=5 degrees. The ratio of the maximum ground surface settlement to the maximum wall lateral deflection decreases at a reduced rate with the increase of delta. For excavation with braced diaphragm wall, the effect of friction between diaphragm and soil on the deflection of diaphragm wall and ground settlement, especially the distribution of ground surface settlement behind diaphragm, should be taken into account.