A Semi-analytical Solution of Time-Dependent Ground Settlement Induced by Excavation in Soft Clay

Using the Lame equation and the three-parameter viscoelastic foundation model, the solution of time-dependent ground settlement induced by displacement of the retaining wall was derived. Based on a 30.2 m ultra-deep foundation pit in Hangzhou soft clay, the solution was validated. The results indicate that (1) The creep will induce ground settlement that does not depend on the extra displacement of the retaining wall, which not only causes the ratio of the maximum ground settlement (wm) to the maximum displacement of retaining wall (dm) during excavation to be much greater than that of non-soft clay foundation pit, but also causes the continuous ground settlement during basement construction. (2) The ground settlement induced by creep increases with the displacement of a multi-strutted wall, showing a concave settlement mode. (3) wm/dm is primarily affected by the creep characteristics of soft clay and the construction time, and seems independent of the displacement of the retaining wall.