Three-dimensional finite element analysis of impact of utility tunnel construction on overlying deep excavations

A shielding method utility tunnel is constructed underneath the foundation pit using the cover-excavation method in Shenyang. Based on the analysis and comparison of the measured data of this project, a three-dimensional finite element model is established using the HSS constitutive model. The deformation of the retaining structures, the strut settlement and the deformation of the finished structures in the pit caused by tunnelling are analyzed. The research shows that the characteristics of the tunnelling underneath the foundation pit can be described appropriately using the HSS model. The underneath tunnelling will induce differential settlement at the top of the retaining structures. The settlement of the finished structures and struts in the foundation pit increases gradually from the middle part to the two sides near the retaining structures. The reasonablely designed columns can control the settlement of the struts effectively.