基于滑带完整性指标的三峡库区堆积层滑坡失稳破坏判据

滑坡稳定性评价是滑坡防治中关键问题之一, 滑坡失稳破坏判据研究可为滑坡稳定性评价提供支持。为了提高滑坡稳定性评价的精度, 以滑坡深部位移监测数据为基础的滑坡失稳破坏判据不失为一种有效方法。基于滑坡深部位移监测数据, 引入滑带完整性指标, 推导得到了滑带完整性指标与滑坡抗剪强度参数之间呈正比例关系; 运用滑坡稳定性计算方法和三峡库区堆积层滑坡简化模型, 获得了滑带完整性指标与滑坡的稳定性系数之间呈正比例关系。建立了考虑滑带完整性指标的三峡库区堆积层滑坡失稳破坏判据, 即: 当滑坡滑带土完整性指标大于滑坡滑带土完整性指标的临界值时, 滑坡处于稳定状态; 当滑坡滑带土完整性指标小于滑坡滑带土完整性指标的临界值时, 滑坡发生失稳破坏。以三峡库区典型堆积层滑坡——五尺坝滑坡为例, 通过实例分析发现该判据具备可靠性, 对堆积层滑坡适用性好。研究成果表明, 滑带完整性指标失稳破坏判据可以用于评价滑坡的稳定状态, 为滑坡失稳破坏判据研究提供了一种新思路。 

Instability failure criterion of debris landslide in the Three Gorges Reservoir Area based on the sliding zone integrity index

The stability evaluation of landslide is one of the key issues in the field of landslide prevention and control. The research on the landslide failure criterion can provide the support for the stability evaluation of landslides. In order to enhance the accuracy of landslide stability evaluation, the landslide failure criterion based on the monitoring data of deep displacement is an effective approach. Therefore, based on the deep displacement monitoring data of landslide, the sliding zone integrity index is introduced, and a directly proportional relationship between the integrity index of the sliding zone and the shear strength parameters of the landslide is deduced. By using the calculation method of landslide stability and the simplified model of debris landslide, a directly proportional relationship between the integrity index of the sliding zone and the stability coefficient of the landslide can be obtained. The instability failure criterion of the debris landslide in the Three Gorges Reservoir Area considering the integrity index of the sliding zone is established accordingly. In the case of the integrity index of the sliding zone is greater than the critical value, the landslide is in a stable state. Otherwise, in the case of the integrity index of the sliding zone is less than the critical value, the landslide is unstable. A typical debris landslide e.g. Wuchiba landslide in the Three Gorges Reservoir Area is analyzed in detailed as an example.It is found that the failure criterion is reliable and applicable for the Wuchiba landslide. The results show that the failure criterion of slip zone integrity index can be used to evaluate the stability of landslide, which can provide a new approach for the study of landslide failure criterion.