蠕滑型边坡动态稳定性系数实时监测及其位移预警判据研究

Real-time monitoring of dynamic stability coefficient and displacement criterion of the creep slope

滑坡的蠕滑位移过程本质上就是滑坡岩土体的损伤变形演化过程。因此,在系统分析蠕滑型边坡不同蠕滑变形阶段的变形演化特征与损伤破坏机制基础上,运用损伤力学基本原理,探索和揭示边坡蠕滑变形与其稳定性系数的相互内在联系,确定边坡的蠕滑位移与其坡体损伤变量及其稳定性系数的定量关系,并依此建立基于边坡蠕滑位移参数确定其动态稳定性系数的方法;同时,依据位移–时序曲线切线角速率和加速率参数变化规律,研究和确定基于安全系数的边坡稳定性位移监测预警判据crS和边坡安全稳定预警时间crt。最后,以典型鸡鸣寺滑坡为例,运用蠕滑型边坡动态稳定性系数与位移监测预警判据,对该滑坡的稳定性演化过程进行后验分析与评价,并同时与斋藤迪孝法预测结果进行对比,其分析评价结果与该滑坡实际稳定演化规律基本吻合,表明所提出和确定的有关位移监测预警判据参数,在蠕滑型边坡的稳定性评价与预测中具有一定的实用性和有效性。

The process of creep displacement of landslide is essentially a damage process of rock mass of slope. The interaction between the creep deformation and the stability coefficient and the quantitative relationships of the creep displacement,the damage parameters and the stability coefficient were therefore investigated based on the systematic analysis on the deformation characteristics and the failure mechanisms of different deformation stages of creep landslide. The method of determining the dynamic stability coefficient of slope based on the creep displacement parameter was established. According to the safety factor of slope from the limit equilibrium method and the variation of the tangent angular rate and acceleration rate parameters of displacement curve,the displacement monitoring and early warning criterion crS and the early warning time points crt before sliding based on the safety factor of slope stability were determined. The typical landslide at Jimingsi was studied as an example and the results were compared with the ones from the method of Saito Michitakanori. It was found that the results of the analysis were basically consistent with the measured variation of the landslide.