Time-dependent solution for ground settlement induced by excavation in soft clay

Upon comparing the theoretical and measured results, it was observed that the current methods need to be revised in predicting ground settlement induced by excavation in soft clay with significant creep effect. With Lame equation and three-parameter viscoelastic foundation model, the time-dependent semi-analytical solution for ground settlement induced by arbitrary displacement of flexible retaining wall was derived. The solution was implemented in two excavations in Hangzhou soft clay, analyzing both the developments of ground settlement from excavation to basement construction and the influences of various factors. The results indicate that: (1) ground settlement induced by soft soil creep does not depend on extra lateral displacement of retaining wall. Soft soil creep not only leads to a much greater δvm/δhm during excavation compared to excavation in non-soft clay, but also causes continuous ground settlement during basement construction. (2) Ground settlement induced by soft soil creep increases with lateral displacement of retaining wall, showing a concave settlement mode. (3) δvm/δhm of deep excavation in soft clay is primarily affected by creep characteristics of soft soil and construction time, and seems independent of lateral displacement of retaining wall.