The Interactional Deformation Behavior Of Synchronized Excavation Of Adjacent Deep Foundation Pits

With the development of large-scale urban areas, underground space is becoming cramped, the problem of synchronously excavating adjacent foundation pit is increasingly prominent. Specification of foundation pit does not give a clear instructions of the deformation of control for adjacent foundation pits, and the traditional analysis methods and software of shoring design for foundation pit mainly target single foundation ditch, which is difficult to consider the impact caused by the adjacent excavation. As the current study of deep adjacent foundation pits is still immature, it is insufficient to satisfy the growing needs of engineering practice, so strengthening depth study for the same period of deep adjacent foundation pit excavation is imminent. Design calculation results are large deviations with the actual situation. when Adjacent excavation, due to the soil between the pit is narrow, making the soil excavation sidewall pressure side pressure is limited earth pressure generated by the more traditional small earth pressure theory calculated, while the side wall displacement is small, so in such a pit design, whether in the adjacent side of the support program for proper optimization. Therefore, strengthening the study of the interaction of excavation of adjacent foundation pit is very essential.this thesis use the finite element analysis software named Z_SOIL, based on the HSS small strain hardening soil constitutive model and combined with the measured data of engineering, explored the deformation behavior of the soil between neighboring pit and retaining structure under the synchronously excavating adjacent foundation pits, provided a reference for the future such projects. The main conclusions are as follows:(1) When the distance of the adjacent pit is less than twice excavation depth, the interaction between the adjacent pit are greater; more than twice of the depth of the excavation, the impact of waning; more than three times the depth of the excavation, the impact is very small.(2) when the condition of excavation is parallel, the distortion of the excavation of adjacent foundation pits is least.(3) When not parallel excavation, the later excavation pit making the first excavation pit secondary deformation; it should be strengthened to monitor deformation excavation pit.