预应力锚索抗滑桩治理滑坡应用研究

A study on applications of stabilizing piles with pre-stressed anchor cables in landslides remediation works

预应力锚索抗滑桩与普通抗滑桩相比,其受力状态更加合理。从将预应力锚索抗滑桩作为支程支挡结构的地质与物理模型出发,建立了力学与数学模型,得到该模型的内力分布的解析解,为其结构设计奠定了基础。将双参数法引入到土抗力模数或地基系数的计算并贯穿到整个结构计算中。分别按刚性桩和弹性桩两种物理模式,将锚索视为弹性绞支座,利用抗滑桩和锚索位移变形协调条件,计算出锚索的设计拉力及桩身的内力分布。结合三峡工程库区地质灾害治理的一个工程进行了应用,并将其与采用普通抗滑桩进行了技术与经济对比分析后,体现出这种抗滑结构的优越性。

The technique of anti-sliding piles of pre-stressed cables is an effective measure in landslide control works, which nowadays has wide application in the fields of infrastructure such as transportation construction projects and geo-hazard control in the reservoir area of Three Gorges Project (TGP) in China. However, the design and calculating method concerned need more attention and urgent studies. The piles of this kind are the development on the basis of stabilizing piles. Compared with common anti-sliding piles, they result in a more reasonable force bearing state. In this paper, on the basis of the geological and physical model of this anti-sliding system, the mechanical and mathematical model of piles with pre-stressed cables have been set up, which establishes the foundation of the calculation for the structure design of the system. The analytical and numerical solutions of the established mathematical model have been obtained. in the whole paper, two-parameter method is employed to calculate the coefficient of subgrade reaction or subgrade modulus. The two models of rigid and elastic piles have been discussed respectively, and the former is emphatically discussed, in which the cable will be regarded as an elastic hinge. In consideration of compatibility conditions between piles and cables, the tensile force of cables and the solutions of the internal force distribution along piles shafts are obtained. A case study in the reservoir areas of TGP is presented finally, in which the application of this technique in landslides control works is analyzed and discussed in details.