预应力锚索抗滑桩结构计算方法

预应力锚索抗滑桩作为一种实用有效的支挡工程措施已在地质灾害治理中得到广泛的应用.然而, 其设计与计算方法仍然是一个亟待深入研究的课题.这种技术是在抗滑桩的基础上发展起来的.相对于普通抗滑桩, 其受力状态更加合理. 从这种治理措施的地质与物理模型出发, 建立了其力学与数学模型, 并最终得到其内力分布的解析解, 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中, 并贯穿到整个结构计算中.分别按刚性桩和弹性桩2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.结合三峡库区秭归县水田坝乡下土地岭滑坡治理工程介绍了这种滑坡治理措施的应用, 并与原普通抗滑桩设计方案进行了技术与经济对比分析, 体现出这种抗滑结构的优越性. 

Design Method for Using Stabilizing Piles with Pre-stressed Anchored Cables in Landslide Remediation Works

The technique of stabilizing piles with pre-stressed anchored cables is an effective measure in landslide remediation works, which nowadays has a wide application in many fields. However, the design and calculating methods of this technique need more attention and urgent research work. Stabilizing piles with pre-stressed anchored cables are a development of the technique of using stabilizing piles. Compared to the use of stabilizing piles alone, anchored cables make the state of the forces on piles more reasonable. A mechanical and mathematical model of piles with pre-stressed anchored cables has been set up, based on a geological and physical model of this landslide stabilizing system. This model establishes the foundation of the calculations for the structural design of the system. The analytical and numerical solutions of the established mathematical model have been achieved. The "two-parameter method" is employed to calculate the coefficient of subgrade reactions or subgrade modulus. The two models, of rigid and elastic piles respectively, are discussed, in which the anchored cable is regarded as an elastic hinge. Under the consideration of deformation harmony between anchored cables and the pile body, the tensile force of anchored cables has been obtained, as well as a solution for internal force distribution along the pile body. A case study in the reservoir areas of the Three Gorges Project is presented in the last part of the paper, in which the application of this technique in landslide remediation works is analyzed and discussed in detail.