考虑岩块定向性的汶马高速公路千枚岩堆积体渗透特性试验研究  

Experimental study on permeability of phyllite talus in Whenchuan-Maerkang expressway considering fragment orientation

作　　者：曾彩云 赵晓彦[1] 万宇豪 李晋 ZENG Caiyun;ZHAO Xiaoyan;WAN Yuhao;LI Jing(Department of Geological Engineering at Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学地质工程系,四川成都610031

出　　处：《岩土工程学报》2023年第4期862-868,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41672295)。

摘　　要：汶马高速沿线千枚岩堆积体广泛发育,考虑到千枚岩具有明显的扁平状几何特征,其在堆积体中的空间分布大多具备一定程度的定向性,导致千枚岩堆积体的渗透特性与均质堆积体存在差异。将扁平状岩块的最大面积岩面与水平面的夹角定义为岩块定向角,将堆积体中具有定向性岩块的质量占岩块总质量的比率定义为岩块定向率,采用自制的大尺度渗透仪分别研究了定向角和定向率对千枚岩堆积体渗透特性的影响。试验结果表明:随着定向角的增大,其渗透系数增大,临界水力梯度减小,而破坏水力梯度呈现“减小—增大—缓慢减小”的阶段性演化趋势;随着定向率的增大,其渗透系数增大,临界、破坏水力梯度均减小。研究成果可为千枚岩堆积体的渗透变形研究及水力特性评价提供参考。The phyllite talus is widely distributed along the Wenchuan-Maerkang expressway.Considering that the phyllite has obvious flat geometric characteristics,most of its spatial distribution in the talus has a certain degree of directionality,so that the permeability of the phyllite talus will be different with that of the homogeneous talus.The angle between the maximum area of the flat fragment surface and the horizontal plane is defined as the fragment orientation angle,and the ratio of the directional fragments to the total ones in the talus is defined as the fragment orientation rate.The effects of the orientation angle and orientation rate on the permeability of the phyllite talus are investigated by using the customized large-scale permeameter.The test results show that with the increase of the orientation angle,the permeability coefficient increases,the critical hydraulic gradient decreases,and the failure hydraulic gradient presents a phased evolution trend of"decreasing-increasing-slowly decreasing".With the increase of the orientation rate,its permeability coefficient increases,and both the critical and the failure hydraulic gradients decrease.The research results may provide a reference for the researches on seepage deformation and the evaluation of hydraulic property of the phyllite talus.

关 键 词：千枚岩堆积体 定向角 定向率 渗透特性 

分 类 号：TU413[建筑科学—岩土工程]