微型桩群加固土坡稳定性分析

发布时间：2018-05-25 11:10

本文选题：微型桩群 + 边坡　；参考：《岩土工程学报》2014年12期

【摘要】：微型桩是一种边坡快速加固技术,多大面积成群布置。基于强度折减技术研究了微型桩群加固边坡安全系数的数值计算方法,并对微型桩群加固均质土坡和含软弱夹层土坡的稳定性进行了对比分析。结果表明,微型桩群加固均质土坡的破坏模式与其布设位置关系密切,采用传统非耦合方法假定滑动面位置不变进行微型桩群的工程设计值得商榷;对于均质土坡,微型桩群锚固深度较小时,桩身变形以刚性旋转为主,随着锚固深度的增加,微型桩群的变形由刚性倾斜转化为柔性弯曲变形,对于含软弱夹层边坡,微型桩群的变形主要是弯曲变形;微型桩群最优锚固长度约为滑面以上自由段长度的1.5~2.0倍。削剪作用能够改善微型桩群受力并降低成本;对于均质土坡,当削剪长度小于自由段长度1/4时,不会降低加固边坡的安全系数,对于含软弱夹层边坡,最大削剪长度约为自由段长度的1/2;实际工程中对于可削剪的微型桩部分,无需设计加筋体,仅将钻孔回填压实即可,能够在确保加固效果的同时降低成本。
[Abstract]:Micro pile is a kind of quick reinforcement technique for slope. Based on the strength reduction technique, the numerical calculation method of the safety factor of the slope strengthened by the micro-pile group is studied, and the stability of the homogeneous soil slope strengthened by the micro-pile group is compared with that of the soil slope with weak intercalation. The results show that the failure mode of homogeneous soil slope strengthened by micro-pile group is closely related to the location of the soil slope, and the traditional non-coupling method is used to assume that the sliding plane position is invariable for the engineering design of the micro-pile group. With the increase of anchoring depth, the deformation of micro-pile group is changed from rigid tilt to flexible bending deformation, and for the slope with weak intercalation, the deformation of the pile body is mainly rigid rotation when the anchoring depth is small, and the deformation of the micro-pile group changes from rigid inclination to flexible bending deformation with the increase of anchor depth. The deformation of micro-pile group is mainly flexural deformation, and the optimal anchoring length of micro-pile group is about 1.5 or 2.0 times of the length of free section above the sliding surface. For homogeneous soil slope, when the shearing length is less than 1 / 4 of the free section length, the safety factor of the reinforced slope will not be reduced, but for the slope with weak intercalation, the shear action can improve the force and reduce the cost of the pile group. The maximum shearing length is about 1 / 2 of the length of the free section. In the practical engineering, the reinforcement body is not needed to be designed for the shearing micro-pile, and the drilling hole can be compacted only, which can ensure the reinforcement effect and reduce the cost at the same time.
【作者单位】：中国矿业大学(北京)资源与安全工程学院;中国水利水电第七工程局有限公司;
【基金】：国家自然科学基金项目(41002090) 中央高校基本科研业务费专项资金项目(2011QZ05)
【分类号】：TU473.1

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