Studying The Extension Tunnel Construction Based On The Monitorins And Numerical Simulation

With the rapid development of national economy, highway trafficvolume increase substantially, original highway can’t meet the increasingtraffic demand, so the expansion projects become more and more, inhighway construction played a part. The tunnel in the expansion projectsmust be extension. Because by geological conditions and constructioncondition terrain restrictions, we can’t build the new tunnel, we need buildthe new tunnel on the existing tunnel, in order to increase traffic lanes,wemust expand the tunnel clearance sections. Now studying the originaltunnel extension construction method is rare, so we study it is important.This paper use the oretical research, numerical analysis andmonitoring, rely on a municipal chongqing road tunnel expanding to studythe extension tunnel constrion method, though this method we can get thesurrounding rock and the lining of supporting stress, the strain rule and theconstruction mechanics form, for similar tunnel engineering design andconstruction to provide the reference.In this paper, basing on the actual situation of the tunnel, we have thefollowing some studies:First of all, we use the analytic method to solve the surrounding rockdisplacement and rock stress; Secondly, according to the particularity of thetunnel, we compare the suitable for expansion tunnel construction method,and choose a suitable construction methods for YuZhou tunnel; Again, according to compare the division extension and the full section extensionto decide the method of YuZhou tennel, and analysis the structural stressunder this construction method; Finally, analysising the monitoring datatoget the rock displacement, stress characteristics and so on.Though anlysis the results to obtain the reasonable results. Theresults is the drilling and blasting is effective and the full section extensionis best. And putting forward to the support of the time and optimize thelength of the scheme.The study may be used for both the design and construction of thetunnel expansion, in hopes of the expansion project of the tunnel play apositive role.