Study On The Effect Of Deep Foundation Pit Excavation On The Underground Pipeline In Soft Soils

Underground pipeline is the lifeline of the city, it’s particularly important on protection of the city underground pipeline in excavation. It will seriously affect people’s production activities and daily life once the failure such as pipeline fracture accidents. Therefore, People pay more attention to the research on protection of the underground pipeline during the process of excavation. We could solve the complex space problem by the finite element numerical analysis method. It provides a very good reference value for checking the safety on engineering structure,while the application on the field of geotechnical engineering becoming more and more widely. In this paper, we have a three-dimensional numerical simulation analysis to the Hangzhou Zhong-Da Shen-Ma square foundation pit construction by the ABAQUS software to simulate the excavation of the basic conditions. Analyzed the deformation rate of the underground pipeline parts, which is1.5meters nearly by the foundation pit during the process of excavation. Comparing with the actual monitoring data, put forward the weak position of the underground pipelines and reinforced the protection measures. It provides a very important reference value for the protection on the underground pipeline during the future foundation pit engineering. There’s less research on deformation rate of the underground pipeline during the process of excavation. The research will also be relevant for the future analysis of the numerical simulation and provide the reference value for other research. In this paper, the main research content includes the following four aspects:(1) Through the finite element software ABAQUS, we set up a3D model of excavation construction process based on Hangzhou Zhong-Da Shen-Ma square. During the process of foundation pit construction, analyzed the displacement of the adjacent pipeline settlement changes in each excavation step. Research the pipeline along the length direction of the horizontal displacement rate and settlement rate. And compared with the actual monitoring data, analyzed the reliability of the numerical simulation results.(2) On the basis of the excavation of the basic conditions, the line on one side of the passive area soil foundation pit reinforcement. During the process of foundation pit construction, analyzed the displacement of the adjacent pipeline settlement changes in each excavation step. And compared with the basic conditions, analyzed the passive area soil consolidation effect of pipeline.(3) On the basis of the basic excavation conditions, the pipeline foundation pit lateral to reinforce the active zone of soil. During the process of foundation pit construction, analyzed the displacement of the adjacent pipeline settlement changes in each excavation step. And compared with the basic conditions, analyzed the pipeline foundation pit lateral soil consolidation effects on the line.(4) On the basis of the basic excavation conditions, reinforced the horizontal displacement of foundation pit pipeline maximize rate or sedimentation rate for pipeline lateral local. During the process of foundation pit construction, analyzed the displacement of the adjacent pipeline settlement changes in each excavation step. And compared with the basic conditions, analyzed the pipeline of pipeline foundation pit lateral local soil consolidation effect.