Excavation Simulation Analysis Of Shallow Buried Parallel Tunnel

With the continuous development in urban economy and Midwestern regionexploitation, the communication industry has stepped to a peak period. The roadtraffic becomes more and more saturated，many cars appear on the road. Developingthe underground traffic has been a necessary part of communication industry. Shallowburied small spacing parallel tunnel is one type of tunnel in division of trafficconstruction. However, because Shallow-buried small spacing tunnel is morecomplicated than the ordinary tunnel, we must guarantee the safety in the constructionand decrease the effect of the tunnel to environment. This paper relies on1#tunneland southern substation tunnel of the Chongqing urban rail transit sixth line inZhongliangshan. The principal research contents and theoretical achievement are asfollows:①We do detail analysis of the ground settlement mechanics which was causedby the excavation of shallow buried sub-surface excavated tunnel, enumerating theaffecting factors of ground settlement caused by excavation and domestic and foreignresearch status.②We summarize basic construction Mechanics fundamentals and constructionmethods systematically and describe the basic fundamentals of finite element,meaning of finite element discretization, the change of surrounding rocks field andhow to simulating method in the process of tunnel excavation.③Doing research on stability of surrounding rocks and instability mechanism ofsurrounding rocks, some work were done to analyze the yield criterion in weak planeand the most unfavorable position.④We do partition of Shallow-buried and deep-buried tunnel systematically anddo theoretical analysis of formation of loosen pressure cause by tunnel construction.We briefly describe the ground damage patterns in tunnel construction.⑤According to the design data of the construction characteristics of1#tunneland southern substation tunnel of the Chongqing urban rail transit sixth line inZhongliangshan, ensuring precondition of the safety in the process of construction, wemust decrease of the tunnel’s effect on environment. By controlling the buried depth,we use the large finite element software ANSYS in solving2D finite elementnumerical simulation. By doing research on ground settlement, structure stress andstrain and internal force of lining, some basic laws are gotten and we get the optimal burial depth. What we have done can provided reference to the similar engineering indesign and construction.