Study On The Applicable Construction Method Of Multi-arch Tunnel

Since the Reforming and open up,along with the rapid development of traffic project in our country, According to the incomplete statistic , there are more than 200 double-arch tunnels builded or being builded. Construction in group of double-arch tunnel has become a trend in our country. The decision of the construction project during the design of the double-arch will effect straight the force-suffered correctly or not of the structure,the length of construction period,the high efficiency or not and the economy benefit. Before the desicion of construction project, we shoud consider the factor such as: ground condition of the rock,tunnel section structure and area .Referring to former experience only,using indiscriminately will easily cause the waste of a great lot of material and inconsequence on design. So, it has very important practical meaning to project that we analyze the rock transmutation course and breakage rule along with tunnel excavation rightly,study the force-suffered character and rule of timbering structure, and find out the practical construction project and economical safe timbering measure. This article plans that based on the double-arch tunnels with different construction condition, we will study rock transmutation and distribution rule of timbering internal force during dynamic construction for double-arch tunnels with geotechnical engineering software MIDAS-GTS. Considering the economics,force-suffered rationality and construction advantage, we will choose the best construction project for different rock grade, we will also validate rationalit and feasibility of the numerical value analysis project combining spot measure data of hypostatic project item. Then, thereout it will give pertinence suggestions and opinions aim at desingn and constrution so that the tunnel will be excavated and operated successfully. Through numerical value analysis for rock stress,strain,ground surface settlement and middle internal force, it will summarize the excavation project within different rock grade and penetration condition. Based on anterior analysis it will give recommended project to study the force-suffered condition for each timbering structure, thereby give the conclusion on optimized parameter of each timbering struture on different rock grade and penetration condition. At the same time, according to PengJia Garden,JiangGai Road Tunnel, through comparing the spot measure data of hypostatic project item and numerical value result, we will come to a conclusion that ground surface settlement,rock transmutation,timbering structue and so on accord with numerical value result along with the construction, thereinto excavation to top half section is the most dangerous period. This article will give a referrence for choice to construction project of double-arch tunnel.