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针对2008年初南方罕见的极端冰雪气候,为研究其与地质灾害的相关性,探讨了极端冰雪灾害条件下均质松散堆积体边坡的演化特征。比较了融雪与降雨触发滑坡的异同点,通过具体事例分析了融雪触发滑坡灾害的一般规律。引入度日因子与雪雨当量两个物理量,根据南方极端冰雪气候特征建立了简化的有效融雪模型,并从渗流场、稳定性及变形3个方面模拟计算在不同雨雪当量下均质松散堆积体坡体的演化特征。结果表明,一定的融雪速率与融雪量对松散堆积体边坡渗流场无影响。随着融雪的持续,非饱和区基质吸力逐渐减小,坡体整体稳定性逐渐降低。坡面上水平位移与竖向位移逐渐增大,表现为水平方向上前缘变形大于后缘,竖直方向上后缘下错与前缘隆起。在融雪持续一段时间后,坡体失稳破坏。
In order to study the correlation between the extreme ice and snow weather rare in the south of China in early 2008 and the geological disasters, the evolution characteristics of the slope of homogeneous loose sediments under extreme ice and snow disasters were discussed. The similarities and differences between snowmelt and rainfall triggered landslide are compared, and the general law of snowmelt triggering landslide disaster is analyzed through concrete examples. By introducing two physical quantities, such as degree-day factor and snow-rain equivalent, a simplified and effective snowmelt model was established according to the extreme ice-snow climate in southern China. From the three aspects of seepage field, stability and deformation, Body slope evolution characteristics. The results show that certain snowmelt rate and snowmelt volume have no effect on seepage field of loosely packed slope. With the continued snowmelt, the suction in the unsaturated zone gradually decreases and the overall stability of the slope gradually decreases. The horizontal displacements and vertical displacements on the slope gradually increase, showing that the deformation of the front edge in the horizontal direction is greater than the rear edge and that of the rear edge in the vertical direction is uplifted. After the snow melt lasted for a period of time, the slope instability destroyed.