Highway High Rock Slope Stability Study

With the rapid development of economic construction in China, the constructions of superhighway become more and more urgent. For the complexity and particularity of the geological conditions, scale and efforts of engineering construction, the geologic hazard of slope is more serious. Moreover the questions of slope extend from the simple slight slope to the high complicated rock slope. Therefore, the research on slope stability becomes more important. Most rocks slopes are made up of anisotropism, inhomogenize and discontinuous medium. Under erosion, down-cutting and excavation, the direction and value of the stress of rock slope is adjusting and changing constantly. And the distribution law of the initial geostress in each area is also different, so the distribution and change law of the stress is quite complicated.This paper is based on the scientific and technological project of the traffic of Hunan Province: The stability study of bank slope in bridge foundation and abrupt slope in road bed at superhighway in the mountain area. At first, the qualitative and quantitative analyze methods in rock soil projects are synthetically summed up, and the numerical analysis principle is explained. Based on the basic idea of elastic - plastic FEM of rock mass materials, the rock mass materials'parameters have been rationally assumed, and then the general relationship on Elastic-plastic constitutive equation is set up by using various yield conditions and criterions. And the loading methods and slope safety factors are studied at the same time. Considering the fact of anchoring in engineering, the function of the anchor is added into the constitutive relationship of rock and joint, then the constitutive relationship which have considered the effect of anchor and joint of elastic-plastic is set up. Finally, this method for jointed rock high slope is applied in a bank slope of superhighway. Using the compiled FEM program and the current software ANSYS to contrastively analyze the canyon base bank slope stability, the character of stress and displacement of bank slope in the natural state and the bridge's setting up state, the character of the local stress and displacement of the enhance bridge base are contrastively studied. At last, the effect of anchor rod is considered in the numerical simulation. The numerical examples illustrate that this method can easily and accurately analyze the problem of slope stability, and analysis shows that the calculated results accord with the reality of the project. The analysis method and results can be used to settle the correspond problems of practical project, and the special examples used in this paper contain a lot of previously known results.