高速公路岩质高边坡稳定性研究

【作者】 王浩；

【导师】 熊渊博；

【作者基本信息】 湖南大学 ， 工程力学， 2007， 硕士

【摘要】 随着我国经济建设的高速发展,对高等级道路的建设需求也不断地扩大。由于中西部地区地质条件的特殊性和复杂性,工程建设规模和力度越来越大,边坡地质灾害也更为突出,边坡问题从简单的土坡延伸到复杂的岩质高大边坡,因此岩质边坡稳定性研究将变得更加重要。大多数边坡岩土体是由非匀质,各向异性的不连续介质组成,自然边坡在受侵蚀、下切和人工边坡开挖过程中,边坡岩体的应力方向和大小,在不断地发生调整和变化,加上各地区初始地应力的分布规律亦各不相同,因而边坡岩土体中应力的分布、变化规律是相当复杂的。本文基于湖南省交通科技项目——山区高速公路桥基岸坡及陡坡路基稳定试验研究,研究高速公路岩质高边坡稳定性问题。首先综合归纳了岩土工程分析的定性、定量的方法,阐述了数值分析原理;从岩体材料的弹塑性有限元的基本思想着手,对岩体材料参数进行合理的假设,并且利用各种屈服条件和准则建立起了弹塑性本构方程的一般表达式,同时对加载方法和边坡安全系数进行了研究;考虑到工程锚固的实际,将锚杆的作用加入到岩体及节理的本构关系式中一起进行考虑,建立起加锚节理岩体的弹粘塑性本构关系式。最后以某高速公路上一处大桥岸坡为例,利用编写的桥基岸坡稳定性分析程序,进行峡谷岸坡稳定性有限元数值模拟分析。使用有限元程序ANSYS及自行编写的有限元程序对两岸坡作为整体进行了对比模拟研究。通过天然状态下岸坡应力位移特征与设桥后岸坡应力位移特征以及两桥基局部应力位移特征进行对比分析,最后再考虑锚杆的作用,得出相应的结论。计算结果表明该法实用可靠,符合工程实际。本文的解答结果不仅可应用于工程实际的相应问题。而且作为本文特例包含了以往文献的若干结果。更多还原

【Abstract】 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.更多还原