白鹤滩水电站层间错动带的剪切特性  

SHEAR BEHAVIORS OF INTERLAYER STAGGERED ZONE AT BAIHETAN HYDROPOWER STATION

作　　者：徐鼎平[1] 冯夏庭[1] 崔玉军 江权[1] 江亚丽[3] 黄可[3] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]法国国立路桥大学,法国巴黎77455 [3]中国水电工程顾问集团公司华东勘测设计研究院,浙江杭州310014

出　　处：《岩石力学与工程学报》2012年第A01期2692-2703,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2010CB732006));中国科学院重点部署项(KZZD–EW–05);国家自然科学基金资助项目(40902090)

摘　　要：基于白鹤滩水电站层间错动带的室内和现场剪切试验结果,对层间材料、层间材料/母岩接触面(土/岩接触面)的剪切力学特性进行研究。试验结果表明,层间材料和土/岩接触面都表现出无剪胀行为的理想弹塑性力学特性;层间材料的蠕变特性不明显;土/岩接触面的抗剪强度与接触面形貌密切相关,接触面越粗糙,其抗剪强度就越高。比较层间材料的室内和现场直剪试验的抗剪强度可知,试样具有强烈的不均匀性。试样扰动对其抗剪强度的影响要比材料变异性的影响小。尺寸效应使得室内试验获得的内摩擦角要比现场试验获得的大。黏粒含量是影响层间材料抗剪强度的重要因素:随着黏粒含量的增加,内摩擦角减少,黏聚力增大。层间材料的抗剪强度对初始饱和度的变化不敏感。室内试验和现场试验结果在黏粒含量和初始饱和度影响上表现出良好的一致性,说明试样的尺寸效应和变异性只是影响其抗剪强度的次要因素。Based on the results of in-situ direct shear tests and laboratory shear tests on interlayer staggered zones at Baihetan hydropower station, the shear behaviors of interlayer material and interlayer material/host rock interface（soil/rock interface） were investigated. It is observed that both of interlayer material and soil/rock interface show an elastic perfect-plastic behavior without dilatancy. Creep of interlayer material is found to be insignificant. The interface roughness dependent of shear strength of soil/rock is identified, namely, the rougher the interface is, the higher the shear strength is. A comparative analysis was performed based on the shear strength parameters from in-situ and laboratory direct shear tests on the interlayer material. It is evidenced that the heterogeneity of samples is significant under both laboratory and field conditions. The sampling disturbance seems to be a factor less important compared to the sample heterogeneity. The size effect is evidenced by the larger internal friction angle obtained in laboratory on small samples than that obtained in the field on large samples. The clay fraction is found to be an important factor, and its increase reduces the internal friction angle and increases the cohesion. Despite the significant data scatter, the effect of initial degree of saturation is identified to be negligible. A good consistency is observed by the comparison of the results from the field tests with those from the laboratory tests in terms of effects of clay fraction and initial degree of saturation, indicating that sample size and sample variability are secondary factors that influence the shear strength of interlayer material.

关 键 词：水利工程 白鹤滩水电站 层间错动带 剪切特性 不均匀性 饱和度 黏粒含量 

分 类 号：TV62[水利工程—水利水电工程]