Research On Numerical Simulation Of The Construction Process Of Double-Arch Tunnel In The Sotf Surrounding Rock

When constructing senior highways in China,the project of double-arch tunnel is often adopted in special geologic and limited topography districts in order to meet the need of road type and outspreading road, to get better technological and economical purpose.At present considerable amount double-arch tunnels have been constructed in our country. But there are many problems in the construction and mobilization of the double-arch tunnels such as construction method is single,construction mechanics not definitude and the theory of design and construction that we can make for reference is scarce.Based on the Xiaojinkou double-arch tunnel engineering of the Guanghui highway,the thesis discusses the distibution of the stess field and displacement field of the surrounding rock , of the stress field of the supporting structure and the central wall by using the plane elastic and plastic FEM to simulate the constructing process and analyzing data of the field.The result is that the three heading construction method is prior to the central heading full cross method on controlling the settlement of the arch top and the stress of the supporting structure and central wall.Then the thesis studies the changing law of the settlement of the arch top, of the stress of the supporting structure and the central wall under the same and differ stress leasing rate of the surrounding rock in the construction of three heading construction method. The thesis studies the distribution law of the plastical region in the three heading construction process also.At last the thesis analyses data of the field and discusses changing law of the supporting structure by comparing its result with result of numerical simulation.So the thesis has the guiding significance to the design and construction of the similar tunnel engineering.