锚固力作用下的边坡临界滑动场法研究与应用

Critical sliding field method for slope under anchorage force and its application

极限平衡方法计算锚固力作用下边坡稳定性时,通常将锚固力作为集中力处理,得到的滑面正应力和条间力分布曲线极不合理。除此之外,若按常规方法处理锚固力的作用,采用临界滑动场法分析锚固边坡稳定性时,搜索的滑动面会产生突变。为克服以上固有缺点,将半无限体受法向力作用的弹性力学解答近似作为锚固力在边坡体内产生的附加应力等效模型,并在此基础上建立了锚固力作用下的边坡临界滑动场计算方法,且通过算例分析表明了这种集中力近似等效处理方式的合理性,进一步丰富了锚固边坡稳定性分析方法。算例分析与工程应用表明,锚固力的作用会改变边坡临界滑动面位置,该方法能够搜索到锚固力作用下的合理临界滑动面,且滑面正应力和条间力分布曲线也较合理,相应的安全系数也较可靠。同时,该法能够全面评价边坡的整体和局部稳定性,可为实际边坡工程提供欠稳定区域的空间分布情况,使其得到有效的治理。

When calculating slope stability under anchorage force by limit equilibrium method, anchorage force is usually treated as a concentrated force, and the distribution curves of normal stress on slip surface and inter-slice forces are very unreasonable. In addition, if the effect of anchorage force is treated by conventional method and the stability of anchored slope is analyzed by critical sliding field method, the sliding surface searched will change abruptly. In order to overcome the above inherent defects, the elastic solution of semi-infinite body subjected to normal force is approximated as the equivalent model of additional stress generated by anchoring force in slope body. On this basis, the calculation method of critical sliding field of slope under anchoring force is established. The analysis of examples shows that the approximate equivalent treatment method of concentrated force is reasonable, which further enriches the stability analysis method of anchored slope. The method has also successfully applied to evaluate the stability of a practical complex slope engineering. The results show that the anchorage force can change the location of the potential slip surface. The proposed approach can search the real potential slip surface with reasonable distribution of normal stresses and inter-slice forces under the action of anchorage force and the corresponding safety factor is more reliable. Meanwhile, the method can comprehensively evaluate the overall and local stability of the slope, and provide the spatial distribution of the unstable region for the actual slope engineering, so as to effectively control it.