中文摘要：

被触发碎片流动的机制在使用人工的降雨的地里被探索在二试验溪谷， Dawazi 溪谷和 Aizi 溪谷，在里面云南和四川省，中国分别地。在两个地点的土壤赤裸、松开、连贯石子主导。结果一直接砍测试，使用团稳定性计算显示的土壤的 rheological 测试和背分析负责触发碎片流动的机制在静电干扰和土壤的动态抵抗包含了减少。被触发的过程能被划分成 7 阶段：降雨渗入，过量流量的产生，高毛孔浇压力，表面侵蚀，土壤爬，滑倒的土壤，被触发的碎片流动和碎片流动增长。另外，二关键步是明显的：(i) 在土壤的过程期间质量从静电干扰变化一活动州，它的结合严厉地减少了(例如，在 Dawazi 的土壤团的结合溪谷从 0.520 ～ 0.090 kPa 减少了， 83% 的减少) 。这将在滑倒期间减少土壤力量和动能，最后触发了碎片流动。(ii ) 当土壤团开始滑倒时，速度和体积碎片增加流动由于土壤的相互作用波动抵抗和滑动力量。来自斜坡的来源区域的代替的土壤团导致了土壤的体积的免职超过 7 - 比那大 8 倍在里面来源区域。

英文摘要：

The triggering mechanisms of debris flows were explored in the field using artificial rainfall experiments in two gullies, Dawazi Gully and Aizi Gully, in Yunnan and Sichuan Provinces, China, respectively. The soils at both sites are bare, loose and cohesive gravel-dominated. The results of a direct shear test, rheological test and back-analysis using soil mass stability calculations indicate that the mechanisms responsible for triggering debris flows involved the decreases in static and dynamic resistance of the soil. The triggering processes can be divided into 7 stages： rainfall infiltration, generation of excess runoff, high pore water pressure, surface erosion, soil creep, soil slipping, debris flow triggering and debris flow increment. In addition, two critical steps are evident： （i） During the process of the soil mass changing from a static to a mobile state, its cohesion decreased sharply （e.g., the cohesion of the soil mass in Dawazi Gully decreased from 0.520 to 0.090 kPa, a decrease of 83%）. This would have reduced the soil strength and the kinetic energy during slipping, eventually triggered the debris flow. （ii） When the soil mass began to slip, the velocity and the volume increment of the debris flow fluctuated as a result of the interaction of soil resistance and the sliding force. The displaced soil mass from the source area of the slope resulted in the deposition of a volume of soil more than 7 - 8 times greater than that in the source area.