Model Test And Numerical Analysis On Surrounding Rocks Stability Of Dayaogou 2^nd Tunnel

With the fast development of national economy of our country, the construction of the highway is developing quickly, too. More and more tunnels are under construction. The construction of highway tunnels are not only highly cost, but also very impotant for the control of the construction period of the hignway project. In the course of the highway tunnel construction, faults and karst cavernrns are encountered commonly. It is very difficult to make certain the mechanism of surrounding rocks unstability and destruct when tunnel constructd.. So, it is increasingly important for the study of how faults and karst cavernrns affect the stability of tunnel surrounding rock.In this thesis, by taking the Dayaoggou 2nd tunnel project as an example. From the construction field investigation, fault and kast caverns are discoved and they are the key difficult problems during the process of tunnel construction. In present day, more and more researchers and engineers pay much attention to the study of faults and karst caverns on the stability of surrounding rock is very few, and most of studies are carried out with the method of numerical simulation. Model test studies in these fields are rarely seen. Therefore, in review of the advantages of model test, such as authentic visual and comprehensive, on the base of the presently laboratory conditions of NEU, this thesis want to take model test study as the main method, and numerical simulation as the assistant method in the research of the mechanical behavior in the failure and destruction process of the surrounding rock.A set of model tests are carried out in laboratory. Takes the geometric scale and gravity scale as the main scale, the comparability that controls all physical and mechanical parameters in elastic condition is realized. Then proportioning test is proceeded. Tunnel models are also manufactured.And models with faults and karst caverns in different positions are carried out to study the influnce of faults and caverns to the stability of the surrouding rocks.On the basis of the results of model test, the thesis makes the 3D FEM numerical simulation analysis. The numerical simulation results are adopted to verify with the test results. From the research in this thesis we can get some useful results, the conclusions can play a directive role in tunneling construction and many valuable advices have been given.