Research Of Surface Subsidence Caused By The Large Rectangular Pipe Jacking Tunnel Excavation

With the rapid development of urbanization,people pay more and more attention to the development and utilization of urban underground space.Pipe jacking method as a kind of tunnel non excavation technology,mainly is the relay and the top of the cylinder and pipe jacking force,the tool pipe from the originating within the shaft is pushed into soil and has been the top to receive and hoisted out well,with the tool tubes behind the tube section of natural laying in two as well in the middle of the tunnel construction method.Although the method of pipe jacking construction excavation quantity is small,fast and convenient,but in the construction process to avoid the disturbance of soil,cause the stratum movement;Compared to those of circular pipe jacking,especially large section rectangular pipe jacking on soil disturbance greater,on the surrounding environmental hazards will be greater.This paper to Zhengzhou City Wear Zhongzhou Avenue rectangular pipe jacking tunnel project as the background,using the finite element analysis software MIDAS/GTS simulate pipe jacking tunnel excavation process,in-depth and systematic analysis and Research on the deformation of the surface in rectangular pipe jacking tunnel construction and draw some conclusions useful for engineering.The main research contents include:(1)Study on the mechanism of surface subsidence caused by pipe jacking construction,analysis of the disturbance on the deformation of soil.(2)Based on the in-situ monitoring of surface deformation caused by rectangular pipe jacking construction,and carries on the analysis and Research on monitoring results.(3)Influence of pipe jacking tunnel surface subsidence on the thickness and study the upper soil grouting,driving pressure and other factors.(4)Based on on the basis of above research,in-depth analysis of the rectangular pipe jacking construction caused ground deformation and deformation mechanism.Furthermore,to how to deal with the ground surface settlement control in the reasonable scope proposed the practical control measures;to achieve environmental protection type underground jacking construction,for the design and construction of similar projects.(5)On the basis of the above research content,and then put forward the control measures for how to control the surface settlement in a reasonable range.