蠕动型滑坡滑带土蠕变特性研究  

Creep properties of sliding-zone soil from a creeping landslide

作　　者：孙淼军[1] 唐辉明[2] 王潇弘 胡新丽[2] 汪明元[1] 倪卫达 SUN Miao-jun TANG Hui-ming WANG Xiao-hong HU Xin-li WANG Ming-yuan NI Wei-da!(Engineering Exploration and Survey Department, Power China Huadong Engineering Corporation Limited, Hangzhou, Zhejiang 311122, China Faculty of Engineering, China University of Geoscienees （Wuhan）, Wuhan, Hubei 430074, China School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450045, China)

机构地区：[1]中国电建集团华东勘测设计研究院工程勘测处,浙江杭州311122 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]华北水利水电大学水利学院,河南郑州450045

出　　处：《岩土力学》2017年第2期385-391,399,共8页Rock and Soil Mechanics

基　　金：国家重点基础研究发展项目(973计划)(No.2011CB710604);国家自然科学基金项目(No.41272305)~~

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%。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.

关 键 词：蠕动滑坡 滑带土 三轴蠕变试验 蠕变特性 长期强度 

分 类 号：TU411[建筑科学—岩土工程]