Study On The Influence Of The Construction Of New Tunnel On The Existing Overlapped Tunnel

With the rapid development of urban traffic construction,underground traffic tunnels have emerged,especially in the transportation hubs.During the construction process,the tunnel causes disturbance of the soil,which causes deformation of adjacent structures and,in severe cases,the structure cannot be used normally.Therefore,it is necessary to study the impact on surrounding buildings during tunnel construction.Based on the actual engineering,this paper studies the influence of new tunnel construction on existing overlapping tunnels by finite element method,and discusses the influencing factors such as the positional relationship of overlapping tunnels,different surrounding rock conditions and different tunnel spacing.The main contents are as follows:(1)Study the influence of new tunnel construction on the existing tunnel below,change the mechanical parameters of the soil by numerical simulation,analyze the influence of different surrounding rock grades on the tunnel construction and the existing tunnel structure;establish different numerical values of tunnel spacing and calculate the calculation results.Displacement and internal force analysis explores the range of spacing in which tunnel construction affects the normal use of existing tunnels under different soil conditions.(2)The influence of the new tunnel construction on the existing tunnel is studied,the numerical model soil material and the tunnel spacing are changed,and the influence trend of the soil material and the tunnel clearance on the existing tunnel under different parameters is analyzed.Compare the conclusions obtained in the previous chapter and discuss the influence of different tunnel positional relationships on tunnel construction and existing tunnel displacement and internal forces.(3)Selecting a tunnel project in Zhuhai City,Guangdong Province,which leads to the research project section of this paper,reasonably assumes that the construction conditions are simplified,and establishes a numerical model for practical engineering case analysis.Compare the calculation results with the conclusions obtained in the previous chapter,verify the accuracy of the conclusions and propose construction suggestions for the actual project.