Study On The Influence Of Shallow Excavation On Municipal Underground Pipeline

With the increasingly fast urbanisation process in China, city size has been expanding. In order to ease the traffic pressure and improve traffic safety, at present,they have started construction of the underpass in many cities of the country. The underpass is shallow burial and close to the underground municipal pipelines in space.Therefore, it is easy to cause the deformation of underground pipeline in underground tunnel construction, or even destroy, which lead to engineering accident.This paper summarizes the research results of the current safety control standard at home and abroad, put forward the safety evaluation method of rigid and flexible pipeline during the construction of the tunnel. In order to study influence of shallow excavation construction on surrounding underground pipeline of more accurate,considering the characteristics of small strain of soil, analysing the influence of underground pipeline in shallow tunneling conditions by numerical simulation. The main research contents are as follows:(1) The relevant parameters to small strain hardening soil model is obtained through the three axle shear test and consolidation test of undisturbed clay, then analysis of the impact of underground tunnel construction on undergound pipelines which considering the small strain behavior of soil by using the finite element software PLAXIS;(2) The impact of pipeline buried depth, material, tunnel construction method of underground pipeline deformation and stress is analysed in the process of tunnel construction;(3) Compared with the results of numerical calculation of numerical calculation of small strain hardening soil model and Mohr-Coulomb model,to verify the results of numerical simulation more accurate about considering the small strain behavior of soil.