基于H-B准则点安全系数的岩质边坡锚索锚固长度优化

锚索锚固是岩质边坡常见的锚固手段,合理确定锚索长度对边坡支护设计至关重要。基于Hoek-Brown准则的点安全系数法,对锚索锚固长度的优化确定进行研究。以均质边坡为例,采用FLAC3D内嵌fish语言计算得到边坡内部的点安全系数分布图,据此判断边坡稳定区和非稳定区。再分别假设点安全系数0.85、0.9、0.95、1等值线为潜在滑动面,在此基础上提出4种不同自由段长度的锚固方案,根据各方案下的点安全系数云图讨论锚固效果及边坡稳定性情况,从而确定最佳的自由段长度。结果表明,以点安全系数等于0.95的等值线为潜在滑动面确定锚固长度的方案最优。并以石柱县西沱镇马尿溪桥一侧高边坡某剖面为例,运用该方法对其支护设计方案中锚索长度进行优化,证明了该优化方法的可行性。

Optimal anchorage length of rock slope based on point safety factor of H-B criterion

Anchor cable anchoring is a common means of anchoring for rock slope. In this paper, based on hoek-brown criterion, the optimization of anchorage length of anchor cable is studied. Taking homogeneous slope as an example, FLAC3D embedded fish language was used to calculate the distribution diagram of the point safety factor inside the slope, so as to judge the stable and unstable areas of the slope. On the basis of assuming that the point safety factor of 0.85,0.9,0.95 and 1 isolines are potential sliding surfaces, four anchoring schemes with different free segment lengths are proposed, and the anchorage effect and slope stability are discussed according to the cloud map of the point safety factor of each scheme, so as to determine the optimal length of the free segment. The results show that the optimal scheme is to determine the anchorage length with the isoline with the point safety factor equal to 0.95 as the potential sliding surface. Taking a section of a high slope on the side of MaNiaoXi bridge in XiTuo town, ShiZhu county as an example, this method is applied to optimize the anchor cable length in the support design scheme, and the feasibility of this optimization method is proved.