Wall Deflection and Ground Surface Settlement due to Excavation Width and Foundation Pit Classification

Abstract

Foundation pits have obvious spatial effect, and the lateral wall deflection, ground movement and basal heave stability are closely related with the excavation width. A database of 92 case histories with extensive excavation widths in soft soil in China are collected and analyzed. The maximum lateral wall deflections and maximum ground surface settlements measured are smaller than the case histories there before. With the increase of excavation width, the maximum lateral wall deflections and the maximum ground surface settlements increase firstly and then tend to stable. The database indicates that the type of retaining structure has little relevance to the excavation width of the foundation pit. There are two types of basal heave according to the excavation width, single-peak and double-peak. Three types of foundation pit considering excavation width, named wide foundation pit, normal foundation pit and narrow foundation pit, are proposed based on the slip circle basal heave analysis approach. The classification method is consistent with the measured data and the simulated results.