【作者】 殷苗苗；

【导师】 付宏渊；

【作者基本信息】 长沙理工大学 ， 岩土工程， 2011， 硕士

【摘要】 岩溶分布非常广泛,且地质环境复杂多变,存在很多不确定的危险性因素,岩溶塌陷灾害日益频繁,且通常具有突然性,易造成巨大的损失和严重危害。在修筑高速公路时,由于岩溶塌陷造成路基破坏的情况时有发生,如何对其进行有效处治并减小其造成的危害是一个极大的难题,对其进行研究有很大的必要性。本文通过在路堤中铺设土工织物加筋体来防止这种突然性塌陷,从而减小岩溶塌陷带来的损失。将塌陷坑上方水平加筋体分为临空段、过渡段和锚固段三部分,对其各部分的受力和传力特性进行了分析推算,对锚固段采用比较符合实际情况的线弹塑性模型进行分析模拟,由基本方程导得锚固段水平加筋体弹塑性解答,并结合边界条件建立锚固段端点拔出量及传力长度的解算流程。通过具体的工程实例对弹塑性模型和全塑型模型下的分析结果进行了比较,得到了两种模型结果的误差分析,探讨不同临空段宽度、加筋体刚度、上覆土体高度、界面摩擦角等因素对临空段端部拔出量计算误差的影响,并分析上覆土体高度与锚固段传力长度之间的关系。利用离散元程序对土工织物加筋体处理含溶洞路基塌陷的情况进行了模拟,并对由不同的设计参数所引起的加筋体变形过程进行了数值模拟,然后将模拟分析结果与理论计算结果进行了对比,由于在模型中对加筋体周围的土体考虑有限,使得两者之间存在一定的误差,但是两者之间的趋势基本保持一致,验证了理论计算结果的正确性。更多还原

【Abstract】 The distribution of karst is wide, and geological environment is complex and changeable. The collapse disaster of karst area increases frequently and usually is sudden, causes huge of loss and serious harm. Expressway often encountering karst development area, the subgrade damage caused by karst collapse occurred from time to time. It is a great of challenges to effectively treat and reduce harm.This paper lays the geo-synthetics reinforced body in the embankment to prevent the sudden collapse, thereby reducing the losses caused by karst collapse. The geo-synthetics reinforced body above collapse is divided into overhead, transition and anchor segment, and analyzed its force and force characteristics of each part. The realistic elastic-plastic models is used to simulate anchor section, guided elastic-plastic answers of anchor section by the basic equations and establish calculating process of the pull-out of endpoint in anchor section and the length of the transmission combined with the boundary conditions. The analysis results of the elastic-plastic model and the plastic model is compared through specific projects examples, and obtained error analysis of two models, then explore the impact of the different width of overhead section, the different reinforcement stiffness, the different height of the over soil, the different interface friction angle and other factors on the calculation errors of pull-out of the endpoint in the overhead section, and analysis the relationship between the length of force transfer during anchor section and the height of the over soil.It progresses numerical simulation for the situation of geo-synthetics reinforced body treating subgrade containing cave by discrete element, and simulates the deformation process caused by different design parameter. Then compares the analysis results with theory calculation analysis, because taking the surrounding soil of the reinforcement into account in the model is limited, so there are some errors between the two results. But the trend between the two results remained the same. It validates the correctness of theory calculation results.更多还原