Research On The Slop Stability And Control Technique At The Tunnel Entrance

With the development of social economic, the investment of infrastructure construction is greatly enlarged. As an important part of infrastructural construction of traffic, the application of tunnel is more and more popular. Also, the tunnel has intense relation with slope, especially the twin tunnel. Landform disaster, such as coast, peeling off and dilapidation, is extremely easy induced at the entrance of twin tunnel, as the result of the wide span and complex techniques. Therefore, it is very important to do some researches on the stability of tunnel slope. At present, there is not a uniform quantization standard for the warning index in the tunnel monitor project. The warning system is still immature in monitoring projects. So, it appears very important to research the monitoring control technique.The paper depends on the project of "Some Key Technologies Research during Construction of Tunnels", Construction Project Office of Jiangxi Provincial Communications Department of JingWuHuang(Chang) highway. On the basis of large amount of reality measures data, the basic factor of the slope stability is summarized. Also, the destroying mechanism of the slope is analyzed in the paper. Then the basic destroying patterns of the tunnel slop are presented.Owing to a great quantity monitoring data, five destroyed stages of the tunnel slope are suggested, and the methods for determining the slope stability are discussed. And the influence on the tunnel slope in different excavating mode is analysisd by using the 2-D elastic-plastic model in the GEOFBA^?, a finite element package developed in Tongji University. Also, the protecting measure to the tunnel slope is concluded in the paper.Also, some reseaches on monitoring techniques for the tunnel slope is carried out in the paper. And the monitor warning index for the tunnel slope is presented by consulting some monitor criterions, reality data and numerical computation results. Finally, dynamical simulation has carried out by the 2-D back analysis and 3-D FEM analysis, based on the 1# of BaiYangChong tunnel in JiangXi Province.