The upper reaches of the Minjiang River are located at the junction of the Qinghai-Tibet Plateau and Sichuan Basin, exhibiting a complex geological environment with high mountains and deep valleys. Many ancient dammed lake sedimentary strata are exposed along the valley in this area. The Tuanjie village landslide developed in the sediments of the Diexi ancient dammed lake. In this paper, the basic characteristics of this landslide and the physical and mechanical properties of the rock and soil of this landslide are determined by combining field drilling with laboratory testing. According to the geological environment characteristics and slope deformation characteristics of landslides, the movement mechanism of landslides is simulated by the numerical simulation software PFC2D, and the genetic mechanism of landslides that developed in large thick lacustrine sediments is discussed. The results show that (1) the sliding body, slip soil and slip bed of the Tuanjie village landslide are composed of lacustrine sedimentary soil; (2) the Tuanjie village landslide has undergone multiple reactivations at the front edge. The formation and revival of landslide are closely related to the water level change of Xiaohaizi reservoir, highway construction and operation, heavy rainfall and so on. (3) Additionally, the Tuanjie village landslide has the characteristics of backward traction failure.

岷江上游地处青藏高原与四川盆地交界处，山高谷深，地质环境复杂。该地区沿河谷出露许多古老的堰塞湖沉积地层。团街村滑坡发育于叠溪古堰塞湖沉积物中。本文通过野外钻探与室内试验相结合，确定了该滑坡的基本特征以及该滑坡岩土的物理力学性质。根据滑坡地质环境特征和边坡变形特征，采用数值模拟软件PFC2D模拟滑坡运动机理，并讨论了在大型厚湖沉积物中发育滑坡的成因机制。结果表明：（1）团街村滑坡的滑体、滑土和滑床由湖相沉积土组成；（2）团结村滑坡在前缘经历了多次重新激活。滑坡的形成和恢复与小海子水库水位变化、高速公路建设运营、强降雨等密切相关。（3）此外，团街村滑坡具有后向牵引失效的特点。（2）团结村滑坡在前缘经历了多次重新激活。滑坡的形成和恢复与小海子水库水位变化、高速公路建设运营、强降雨等密切相关。（3）此外，团街村滑坡具有后向牵引失效的特点。（2）团结村滑坡在前缘经历了多次重新激活。滑坡的形成和恢复与小海子水库水位变化、高速公路建设运营、强降雨等密切相关。（3）此外，团街村滑坡具有后向牵引失效的特点。