基于临界压脚体的某滑坡体削坡压脚土方量平衡研究

Study on Earthwork Balance of Slope Cutting and Pressing Foot for a Landslide Based on Critical Pressing Foot

针对某滑坡体治理时压脚土方量大于削坡土方量的问题,通过敏感性分析不同压脚体下滑坡体的安全系数发现,当压脚体的体积增大到一定程度后,滑坡体的抗滑稳定安全系数不再变化,由此提出基于临界压脚体进行滑坡体治理方案。分别对滑坡体高压脚少卸荷、低压脚多卸荷2种治理方案进行不同压脚体下的稳定性分析和土方量计算。分析结果表明,随着导流缺口占河床的比例逐渐减小,2种方案的全局搜索最小安全系数先增大,然后渐趋稳定;临界压脚体对应的导流缺口占河床比例均约1/2。基于临界压脚体进行滑坡体治理,可以较好地解决压脚土方量和削坡土方量的不平衡问题。

For solving the prohlem of the earthwork amount of pressing foot being greater than that of slope cutting in the treatment of a landslide, the sensitivity of safety factor of landslide under different pressing foot body is analyzed. It is found that the safety factor of stability against sliding of landslide does not change when the earthwork of pressing foot increases to a certain extent. So the idea that the landslide is controlled based on critical pressiug toot is proposed. The stabilities of two control schemes of high pressing foot and less unloading, and low pressing foot and more unloading are analyzed and the earthworks are also calculated. The results show that, （a） with the proportion of diversion gap to river bed decreases gradually, the minimum safety faetors of global search for two schemes first decrease and then are almost unchanged; and （b） the proportion of diversion gap to river bed under critical pressing foot is about 1/2. The unbalance phenomenon of earthwork between slope cutting and pressing foot can be better solved for landslide treatment based on critical pressing foot.