岩性特征对混凝土坝体-基岩原位直剪试验力学特性影响分析  

Analysis of Influence of Lithological Characteristics on Mechanical Properties of Concrete Dam-Body-Bedrock In-situ Direct Shear Test

作　　者：张翌娜[1] 胡昊 张建伟 刘佳冰 王勇 ZHANG Yi-na;HU Hao;ZHANG Jian-wei;LIU Jia-bing;WANG Yong(Faculty of Civil and Transportation Engineering,Yellow River Conservancy Technical Institute,Kaifeng 475004,China;School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China;Water Conservancy and Hydropower Engineering Design Institute,Beijing Engineering Corporation Limited,Beijing 100024,China;Pearl River Water Resources Research Institute,Pearl River Water Resources Commission,Guangzhou 510635,China)

机构地区：[1]黄河水利职业技术学院土木与交通工程学院,河南开封475004 [2]华北水利水电大学水利学院,河南郑州450046 [3]中国电建集团北京勘测设计研究院有限公司水利水电工程设计院,北京100024 [4]珠江水利委员会珠江水利科学研究院,广东广州510635

出　　处：《水电能源科学》2024年第2期38-42,共5页Water Resources and Power

基　　金：广州市科技计划项目(2020-ky34)。

摘　　要：以广西巴马县坡月水库工程为研究对象,采用平推法开展不同法向应力(0.4、0.8、1.2、1.6、2.0 MPa)下混凝土坝体-基岩原位直剪试验,探究岩性特征对混凝土坝体-基岩力学特性的影响。结果表明,不同法向应力下试样的剪切应力-位移曲线均表现出试样内部初始缺陷受力微裂纹扩展的稳定扩展阶段、微裂缝逐渐扩展形成宏观裂缝的不稳定扩展阶段及混凝土与岩体分离的开裂阶段3个阶段;法向应力、岩体岩性对试样的断裂能均有显著影响。不同法向应力下,试样断裂能的范围为16.65~177.28 N/m,断裂能随着法向应力或灰色砂岩含量增大而增大,随泥质粉砂岩含量或风化程度增大而减小;混凝土坝体-基岩的抗剪强度随基岩中灰色砂岩含量增大而增大,随泥质粉砂岩含量或基岩风化程度增大而减小。研究结果可为类似研究提供试验参考。Taking the Poyue Reservoir Project in Bama County,Guangxi Province as the research object,the in-situ direct shear test of concrete dam body-bedrock under different normal stresses(0.4 MPa,0.8 MPa,1.2 MPa,1.6 MPa,2.0 MPa)was carried out by flat thrust method,and the influence of lithological characteristics on the mechanical characteristics of concrete dam-bedrock was explored.The results show that the shear stress-displacement curves of the specimen under different normal stresses show three stages:the stable expansion stage of microcrack propagation of the initial defect inside the specimen,the unstable propagation stage of microcrack gradually propagation to form macroscopic fracture,and the cracking stage of separation of concrete and rock mass;Normal stress and lithology of rock mass have significant effects on the fracture energy of the specimen.Under different normal stresses,the range of fracture energy of the specimen is 16.65 N/m-177.28 N/m,and the fracture energy increases with the increase of normal stress or gray sandstone content,and decreases with the increase of argillaceous siltstone content or weathering degree;The shear strength of concrete dam-bedrock increases with the increase of gray sandstone content in bedrock,and decreases with the increase of argillaceous siltstone content or weathering degree of bedrock.The research results can provide a reference for similar studies.

关 键 词：混凝土坝体-基岩 原位直剪试验 力学特性 岩性特征 影响因素 

分 类 号：TV223.1[水利工程—水工结构工程] TV321[建筑科学—建筑技术科学] TU528