中文摘要：

发生在西藏波密县易贡藏布扎木弄沟的易贡滑坡可称为国内规模最大的超高速远程滑坡，引起广大学者的广泛关注。针对易贡滑坡的高速、长距离运动等特点，通过不同剪切速率下的环剪试验以及排水和不排水条件下的对比环剪试验分析易贡高速滑坡的形成原因。结果表明，高速剪切使孔隙水压力不能及时消散，剪切过程引发孔隙水向剪切面运移，剪切面土体含水率和细粒含量明显高于剪切面上下层土体，出现剪切面液化现象。不排水剪切条件下的有效内摩擦角比排水剪切大幅降低，初步揭示了剪切速度越高，土体强度越低，两者交互作用的滑坡加速促进原因。

英文摘要：

Tremendous Yigong landslide occurred in Yigong Riverin Bomi, Tibet. It can be called the largest and longest rapid landslide in China. A lot of researchers paid great attention to the huge rapid landslide and carried out research works on it. Aiming at the characters of high-speed slide and long distance movement, studies were conducted on the mechanism of the slide use of speed and consolidation undraining shear tests. Results show that the pore pressure cannot be dissipated punctually, and that the pore water migrates to the shear zone slowly during the shearing process. The water content and fine particle content in the shear zone are higher than the original ones and those in other layers obviously, the soil liquefaction appears in the shear zone in the consolidation shear tests. The effective internal friction angle of the consolidation undraining shear tests is much lower than that of the draining one. The higher the shear speed, the lower the strength of the soil. This can interprete the formation of tremendous Yigong landslide.