临江Ⅱ号崩滑体土水特征曲线试验研究

Tests for Soil-Water Characteristic Curve of Riverside Slump-mass

三峡水库蓄水后导致许多滑坡失稳,使人们认识到研究非饱和土性质的重要性。为研究巴东黄土坡滑坡土的非饱和性质,选取临江Ⅱ号崩滑堆积体的滑带土及滑体土作为试验对象,按其天然状态配置成重塑样,分别进行了土水特征试验及变水头渗透试验,得到了滑体土和滑带土在不同基质吸力条件下所对应的体积含水率和渗透系数;并对其土水特征试验曲线进行拟合,Fredlund-Xing方程拟合效果优于Gardner方程和指数衰减方程。同时发现土水特征试验在施加第一级基质吸力时很重要,这将影响试验曲线的形状。研究成果将对水库蓄水作用下的库岸滑坡稳定性评价有指导意义。

Many landslides became unstable after the impoundment of the Three Gorges reservoir,raising awareness of the importance of research on unsaturated soil properties.The authors selected the slip-zone soil and slip-mass soil in riverside No.Ⅱ slump-mass as test objects to investigate the properties of unsaturated soil at Huangtupo landslide in Badong county.We reshaped the samples according to their natural states,and carried out tests on soil-water characteristics and tests on varying-waterhead permeability.The volumetric water content and permeability coefficient of both the soil samples under different matric suction conditions were obtained.Having fitted the soil-water characteristic test curves,we found that the fitted result by Fredlund-Xing’s equation was superior to that by Gardner’s equation and index attenuation equation.We also found that the characteristic curve could be influenced by the first-level suction during the test.The research result will serve as a guidance for the stability evaluation of reservoir bank during water storage.