中文摘要：

蠕动型滑坡表现为长期缓慢的变形响应,其演化过程和稳定性受到滑坡滑带土蠕变性质的控制。选取三峡库区典型蠕动型滑坡马家沟滑坡为研究对象,针对该滑体滑带土原状试样开展大尺寸三轴蠕变试验,研究滑带土试样在不同围压和应力水平下的蠕变规律,并进一步采用等时曲线法确定滑带土长期强度与常规强度的差异。研究结果表明,马家沟滑坡滑带土具有典型的稳定蠕变材料特性,蠕变阶段可分为衰减蠕变和稳定蠕变2个变形过程,其变形趋势与滑坡宏观变形演化具有较好的一致性;滑带土绝对蠕变量和稳定蠕变阶段的变形速率均与轴向应力值呈正相关,而衰减蠕变阶段的持续时长随着剪应力水平增加基本呈线性增加。滑带土长期强度参数与常规强度参数比较,其长期黏聚力c值和长期内摩擦角？值分别下降24.8%和22.4%。

英文摘要：

A creeping landslide shows a deformation response of long-term and small-scale, the evolution and stability of which are controlled by the creep response of sliding-zone soil. The Majiagou landslide, a typical creeping landslide in Three Gorges reservoir region, is selected as a case. A series of large-scale triaxial compression tests is conducted on the undisturbed specimens of sliding-zone soil to reveal the creep laws of sliding-zone soil under different confining pressures and stress levels. On this basis, the difference between long-term strength and conventional strength of the soil is determined by the isochronous curves. The results show that the sliding-zone soil of Majiagou landslide has steady creep characteristic, and the creep process can be divided into attenuation creep stage and constant speed creep stage. And the deformation tendency of sliding-zone soil is similar to the macroscopic deformation of the landslide. The absolute creep displacement and the strain rate of constant speed creep stage are positively correlated with the axial stress. While the duration of the attenuation creep stage increases linearly with the shear stress level. The long-term cohesion and the long-term internal frictional angle decrease by 24.8% and 22.4% respectively comparing with the conventional strength parameters.