路堑高边坡稳定性分析与锚固支护研究

【作者】 李怀珍；

【导师】 朱文孝； 王伍军；

【作者基本信息】 贵州大学 ， 岩土工程， 2007， 硕士

【副题名】以三凯高速K113+137～274路堑高边坡为例

【摘要】 国家进行西部大开发以来，随着大量铁路、公路工程向山区的挺进，人类工程活动中开挖切坡形成了大量的路堑高边坡，且高度越来越大。加上我国南方多为丘陵和山区，地层风化深度大，覆盖层较厚，岩体结构破碎，路堑高边坡工程问题更加突出。本文通过对二十多处路堑高边坡的的现场调研、分析，总结归纳出路堑高边坡的特点、影响因素、变形破坏模式。对坡体推力计算常用方法进行介绍的同时，指出目前坡体推力计算中存在的问题，提出了坡体推力计算的原则，并将常见的各种类型边坡按破坏滑动面形式分为5种类型；通过对路堑边坡开挖处老滑坡状态复原和路堑高边坡分步开挖的极限平衡分析、稳定性状态模拟，结合施工前地质勘查资料，得出降雨、地下水和分步开挖对边坡稳定性的影响。近年来，预应力锚索抗滑桩和预应力锚索框架梁新型抗滑支挡结构在路堑高边坡整治中发挥了重要作用，但是其锚固理论的研究还远落后于工程实践。本文对预应力锚索框架梁的坡体加固机理作了总结，将其工作过程分三个阶段进行详细分析。通过分析预应力锚索与岩土体、抗滑桩与岩土体、预应力锚索与抗滑桩之间的相互作用，总结出了预应力锚索抗滑桩的坡体加固机理以及桩、锚两者之间的协调变形关系。对抗滑桩是否需要设置锚索、锚索是否需要施加初始预应力、根据什么条件确定锚索初始预应力值等问题进行了分析。最后本文提出锚固效果的影响因素和评价参数。对工程实例的锚固支护进行了数值模拟，从支护后堑坡的位移大小、安全系数、塑性区分布、抗滑支挡结构的内力分布合理性等几个方面分析、评价坡体的加固效果。在实际工程支护参数的基础上，结合数值模拟，对支护结构参数进行优化设计，提出了既能满足安全要求又有良好锚固效果的优化方案，得出一些既有理论指导意义又有实际应用价值的有益结论。更多还原

【Abstract】 Along with the west development of economic, high cut slopes come forth more and more in traffic construction engineering fields, especially the slopes high becoming higher and higher. Because of high stratums efflorescence level, thick overlay and fragmental rock configuration in mountainous and hill area, high cut slopes engineering problem is more severe and complex.The cut slopes deformation form, affect factors and deformation model are discussed at first. On this base, two quantitative analysis methods were used to analysis the high cut slope stability .at the same time, the state of high cut slope was simulate with FLAC soft in this paper. The paper elicit the characters, affect factors and deformation model of high cut slopes. We indicate the problems when the calculation method of slope down-slip force introduced. At the same time, we suggest the principle of the account about down-slip force. The paper divides the slip model into 5 kinds. Based on limit equilibrium analysis, numerical simulation and geologic datum, we draw some conclusions about the influents of rainfall, groundwater and step excavate to slope.In recent years, the anti-slide piles and frame beam with pre-stressed anchor cables are widely applied to the reinforcement of high cut slopes. But the theory is far below the engineering practice. The paper makes a summary of reinforcement mechanism of frame beam with pre-stressed anchor cables. According to the condition of prestressed anchor cable, three phases such as tension phase, working phase and ultimate working phase are divided. By analysis the reciprocity of prestressed anchor cable between rock and soil, piles between rock and soil, prestressed anchor cable between piles, the paper makes a summary of reinforcement mechanism of anti-slide piles with pre-stressed anchor cables. Weather the anti-pile need pre-stressed anchor cable and pre-stressed, what is the number of pre-stressed anchor cable were analysis in this paper, too.At last, the paper brings forward the effect factors and estimate parameter about reinforcement effect. Across engineering instance numerical simulation, the slope displacement, safety factor, figure area, structure internal force were analysis, the reinforcement effect was evaluated. In the base of engineering instance reinforcement parameters, a superior project was designed. The research of superior project gives a lot of significative and economical conclusion.更多还原