预应力锚索对微型桩结构抗滑性能影响的试验研究
发布时间：2019-07-04 10:04
【摘要】：在传统微型桩顶部联系梁上加设斜向预应力锚索,构成新型复合挡锚结构的锚索微型桩。采用分级加载方式进行双排传统微型桩和锚索微型桩加固土质边坡的室内模型试验,并结合相同条件的FLAC3D数值计算,对比分析锚索微型桩和传统微型桩以及采用两者加固后边坡的变形和受力特征,进而探讨锚索微型桩的抗滑机理。结果表明:相比传统微型桩,经锚索微型桩加固后边坡的变形和联系梁的位移明显减小;锚索微型桩周围产生应力集中区,形成结构—土体的复合骨架体系,阻滞了致滑应力和变形沿滑坡方向的传递;预应力锚索有效增强了微型桩结构的侧向刚度,结构侧向倾斜变形减小;微型桩的内力和外力分布趋于均匀,有利于及时和充分地发挥桩体的力学性能;随着堆载的逐级增加,微型桩结构的变形过程分为小变形、大变形和极限破坏3个阶段,对应的桩—锚荷载分担比呈先增大、后减小和再增大的变化规律,极限破坏阶段的分担比稳定在1.3~1.5之间。
[Abstract]:Oblique prestressed anchor cable is added to the connection beam at the top of the traditional micro pile to form a new type of anchor cable micro pile with composite anchor structure. The laboratory model test of double row traditional micro pile and anchor cable micro pile is carried out in this paper. Combined with the FLAC3D numerical calculation under the same conditions, the deformation and stress characteristics of anchor cable micro pile and traditional micro pile, as well as the deformation and stress characteristics of the slope strengthened by the two methods are compared and analyzed, and then the anti-skid mechanism of anchor cable micro pile is discussed. The results show that compared with the traditional micro-pile, the deformation of the slope and the displacement of the connecting beam are obviously reduced, the stress concentration area around the anchor cable micro-pile is formed, and the composite skeleton system of structure-soil is formed, which blocks the transfer of sliding stress and deformation along the direction of landslide, and the prestressed anchor cable effectively enhances the lateral stiffness of the micro-pile structure and reduces the lateral inclined deformation of the structure. The distribution of internal force and external force of micro pile tends to be uniform, which is beneficial to give full play to the mechanical properties of pile body in time and fully. With the increase of stacking load step by step, the deformation process of micro pile structure can be divided into three stages: small deformation, large deformation and ultimate failure. The corresponding pile anchor load sharing ratio increases at first, then decreases and then increases, and the sharing ratio in ultimate failure stage is stable between 1.3 鈮，
本文编号：2509839
[Abstract]:Oblique prestressed anchor cable is added to the connection beam at the top of the traditional micro pile to form a new type of anchor cable micro pile with composite anchor structure. The laboratory model test of double row traditional micro pile and anchor cable micro pile is carried out in this paper. Combined with the FLAC3D numerical calculation under the same conditions, the deformation and stress characteristics of anchor cable micro pile and traditional micro pile, as well as the deformation and stress characteristics of the slope strengthened by the two methods are compared and analyzed, and then the anti-skid mechanism of anchor cable micro pile is discussed. The results show that compared with the traditional micro-pile, the deformation of the slope and the displacement of the connecting beam are obviously reduced, the stress concentration area around the anchor cable micro-pile is formed, and the composite skeleton system of structure-soil is formed, which blocks the transfer of sliding stress and deformation along the direction of landslide, and the prestressed anchor cable effectively enhances the lateral stiffness of the micro-pile structure and reduces the lateral inclined deformation of the structure. The distribution of internal force and external force of micro pile tends to be uniform, which is beneficial to give full play to the mechanical properties of pile body in time and fully. With the increase of stacking load step by step, the deformation process of micro pile structure can be divided into three stages: small deformation, large deformation and ultimate failure. The corresponding pile anchor load sharing ratio increases at first, then decreases and then increases, and the sharing ratio in ultimate failure stage is stable between 1.3 鈮，
本文编号：2509839
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