The Study Of The Excavation By Blasting Of The Reconstruction And Extension Tunnel And The Technology Of Monitoring And Measurement

With the rapid development of national economy in our country and the increasing amount of traffic, some old tunnel has been unable to meet the growing traffic because of the lower design standards. And the tunnel disease such as: the lining cracking,leaking of water has been occurred,Due to the topographic and geological conditions, constructions,many tunnel can’t build multiple track,there is only one way to expand excavation on the basis of the existing tunnel.From what has been discussed above, we know it is very necessary to expand excavation based on the existing tunnel.In this paper,theory research, numerical analysis and monitoring and measurement is adopted,based on the engineering background of the reconstruction and extension project of Dong Chang Yu tunnel(Xing Fu Tunnel),we studied the tunnel expansion type,construction method,and we get some conclusion that the rule of the stress and strain between the surrounding rock of tunnel and the supporting structure during the construction process.It can provide some reference for the similar reconstruction of tunnel engineering.In this paper, according to the actual situation of the tunnel, some specific research are studied.(1)The expansion type of the tunnel are analyzed,based on the background,reasonable supporting structure is researched;(2)In view of the special of reconstruction and extension of tunnel,the different construction methods of tunnel is compared,and a suitable construction method for Xing Fu Tunnel is put forward to, and a detail study of construction method of the collapse of cavity section(K3+557~K3+586);(3)Different blasting design is raised for different construction methods and construction environment based on the excavation of Xing Fu Tunnel(the extension section and the bifurcation section);(4) Numerical analysis is adopted by the finite element software-MIDAS-GTS,the collapse of cavity section(K3+557~K3+586) is selected to analyze the tunnel excavation process and blasting vibration,the bifurcation section(K3+810~K3+840) is selected to analyze the tunnel excavation process,then the rules of the stress and strain between the surrounding rock of tunnel and the supporting structure during the construction process we get from the numerical simulation is met to the results of monitoring and measurement at the construction site,the guidance the construction of Xing Fu Tunnel.