A Three Dimensional Analysis Of The Deformation Of Retaining Structures For Foundation Pits Based On Additional Earth Pressures

The deformation of retaining structures is actually a 3D problem.Existing 2D analysis methods failed to consider the spatial effects of foundation pits,the interaction between piles and soil,and so on.When calculating the foundation pits engineering with complicated structure and more working conditions,the result was slightly worse.To solve these problems,the following works had been done.1.The 3D analysis program,which could be used for piles retaining structures,was made.The program,which put together the actual earth pressure theory and the additional earth pressure theory,could analyze the internal force and deformation of retaining structures under different conditions,different soil and different excavation depth by modifying the data files and program codes.2.The indoor model tests of the internal force and deformation of piles retaining structures was conducted.The retaining structures' material and size,and parameters of the backfill soil were preliminarily selected.Then according to the program analysis,the depth of the excavation and the arrangement of measuring points were determined.The excavation tests of sand pits were repeated,by which the displacements and bending moments of retaining piles were measured.By comparing the calculations of retaining piles under two kinds of calculation methods of earth pressures with the experimental data,the study on numerical value and distribution of piles' displacements and bending moments was conduct.Finally,the correctness of the program and the applicability of the additional earth pressure theory were verified.3.3D analysis of retaining structures of foundation pits based on additional earth pressure was made.A basic example was made.Detailed researches of the effects of excavation depth,embedded depth of piles and plane size of foundation pits on the inner force and deformation of retaining structures were done.The laws of research significance were get,which provided a reference for the optimization of retaining structures' design.