地震扰动区碎石土滑坡滑动能力分析及预测

Landslide sliding ability analysis and forecast of gravel soil landslide in seismic zone

滑坡规模、形态及地形地貌条件是影响滑坡滑动能力的重要因素。在对汶川地震极震区滑坡详细调查编目的基础上,对都江堰地区51个不同形态地震滑坡的滑动能力影响因素进行了相关性分析,依据相关系数的大小识别出了影响滑坡滑动能力的主要因素。基于最小二乘法原理,采用多元线性回归方法对主要因素进行拟合,获得了研究区地震滑坡的滑动距离预测关系式。研究结果表明:影响该地区地震滑坡滑动能力的主控因素有滑坡体积、滑坡平面形态和滑坡前后缘高差;斜坡原始坡度、坡面摩擦系数和滑坡厚度与滑坡滑动距离的相关性较弱,故认为这些因素对滑坡远程滑动的贡献较少;不同几何形态滑坡的滑动能力主控因素有所差别,对不同形态地震滑坡建立了有针对性的滑动距离预测关系式。

Landslide scale, shape and topography are important factors affecting landslide sliding ability. On the basis of detailed field investigation and inventory for 51 landslides of Dujiangyan area in seismic zone of Wenchuan Earthquake, the correlation of main factors affecting the landslide sliding ability were analyzed. According to the correlation coefficients, the controlling factors for sliding ability were identified. Based on the principle of ordinary least squares, the controlling factors were fitted through multiple linear regression method and the estimation formula of runout distance was obtained. The results show that the controlling factors include landslide volume, sliding surface shape, elevation difference between the front and rear edges; the correlations between the runout distance and the original slope gradient, slope friction coefficient, landslide thickness are week, which means that these factors contribute little to the distant runout. The controlling factors on sliding of geometrically different landslides are different, so specifically targeted runout distance estimation formulas for landslides of different shapes are established.