基于滑坡稳定性的锚索微型桩组合抗滑结构分析

Analysis of the Anchor-micro-pile Composite Anti-slide Structure Based on Stability of Landslide

为了给锚索微型桩组合抗滑结构的设计提供技术支持,对其开展理论研究非常必要.讨论了组合抗滑结构的工作机理,建立了锚索-微型桩-岩土体协同工作的计算模型,采用有限元法进行了求解.基于MATLAB平台开发了面向对象的分析软件,通过微型桩试验验证了分析方法和计算程序的有效性.最后结合算例,采用提出的计算方法对无锚索和不同直径锚索的微型桩抗滑结构进行了分析,并与数值模拟进行了对比,两者吻合较好.结果表明:锚索微型桩结构具有良好的承载性能,桩体弯矩、剪力和水平位移分布趋势相似,其值均为后桩最大、前桩最小,而轴力为后桩最大、中桩最小;随着锚索直径增大,锚拉力增大,边坡水平位移明显减小;滑坡推力作用下组合结构发生压弯变形,设计时前桩和中桩按拉弯验算,而后桩按压弯.提出的计算方法可为抗滑结构的设计提供理论依据.

In order to provide technical support for the design of anchor-micro-pile anti-slide structure,it is of great significance to study its calculation theory.The working mechanism of the anti-slide structure is discussed.The calculation model of the structure under the cooperative work of anchor,micro-pile and soil is established,and it is solved by finite element method.Furthermore,the analysis software for the object-oriented is developed based on MATLAB,and the analysis method and program are verified by the micro-pile model test.In the end,the micro-pile anti-slide structures without anchor and with different diameter of anchor are analyzed through an example.By comparing the calculation and the numerical simulation results,it is known that the two agrees well.The results show that there is a good bearing capacity for the anchor-micro-pile structure.The distributions of the moment,shear force and horizontal displacement in the pile are similar,these values in the rear pile are the maximum while they are minimum in the front pile.The axial force in the rear pile are the maximum while it is the minimum in the middle pile.The force of anchor increases but the horizontal displacement of slope decreases obviously with the increase of anchor diameter.There occurs compression deformation for the combined structure under the action of landslide thrust,which means the front pile and the middle pile should be designed according to stretch bending,while the rear pile should be designed by compression bending.The calculation method proposed in the paper can provide a theoretical basis for the design of anti-slide structure.