The Study Of A Deep Foundation Pit Row Pile-Ring Internal Support System In East Chengdu Stability

In recent years,with the contraction of urban land use and the development of engineering technology,the number of deep foundation pit projects has increased explosively,and the safety problem brought by this has become increasingly prominent.Deformation of support system in deep foundation pit engineering plays a crucial role in engineering safety.Taking Xinhe yulongshan deep foundation pit project in Chengdu city as the research background,this paper simulates and analyzes the stress and deformation of the support system of this project.The main contents are as follows:1.The development status and existing problems of deep foundation pit engineering are briefly introduced.This paper introduces the development status,characteristics and calculation method of internal support system.The advantages and disadvantages of several supporting systems for deep foundation pit are summarized and compared.The key points of construction and quality control of pile-row internal support system are briefly summarized.2.Midas/GTS NX was used to simulate and analyze each construction stage of the foundation pit,and the accuracy and reliability of the established numerical model were verified through the analysis and comparison with the actual monitoring data on site.The variation rules of internal force and horizontal displacement of the pile-row internal support system at different excavation depths were studied.3.Midas/GTS NX was used to analyze the influence of three factors on the force and deformation of the pile-internal support support system: the embedded depth,the pile diameter and the section size of the internal support.Through analysis,the following conclusions are drawn:(1)The axial force on the inner ring of annular inner support is mainly compression.With the continuous increase of excavation depth,the axial force on the inner ring of three inner supports presents an obvious growth trend,and the force on the inner ring of each inner support is approximately symmetrical structure.(2)As the excavation depth continues to increase,the horizontal displacement of the support pile continues to increase,and the displacement curve shows a parabolic shape.Moreover,as the excavation depth increases,the position where the maximum horizontal displacement occurs gradually moves downward.(3)Increasing the embedded depth of the supporting pile can effectively reduce the horizontal displacement of the supporting pile,but has little impact on the internal support force;(4)The larger the diameter of the supporting pile,the greater the maximum and minimum stress of the inner ring of the inner support;The larger the diameter of the supporting pile,the smaller the horizontal displacement of the pile.This simulation analysis of xinhe yulongshan deep foundation pit project provides a reference for the continuation of the following project,and provides a reference for the design and construction of similar projects in the future.