不同温度条件下饱水风化花岗岩强度及变形特性分析  

The strength and deformation characteristics of saturated weathered granite under different temperature conditions

作　　者：李金明 李国玉 彭万林 陈敦 周宇 刘存福 LI Jinming;LI Guoyu;PENG Wanlin;CHEN Dun;ZHOU Yu;LIU Cunfu(State Key Laboratory of Frozen Soil Engineering.Northwest Instiute of Eco Environment and Resources,Chinese Academy of Sciences,Lanzhou 700000,China;Universiy of Chinese Academy of Sciences.Beijing 100049,China;No.3 Geological Team,Bureau of Geology and Mineral Resources of Xinjiang,Korla 841000,Xinjiang,China;Yalong River Hydropower Developmenr Company,LTD,Chengdu 610051.China)

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]新疆维吾尔自治区地质矿产勘查开发局第三地质大队,新疆库尔勒841000 [4]雅砻江流域水电开发有限公司,四川成都610051

出　　处：《冰川冻土》2020年第2期523-531,共9页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(U1703244,41672310,41630636);国家重点研发计划项目(2016YFC0802103);中国科学院战略性先导科技专项(XDA20030201);中科院国际合作局对外合作重点项目(131B62KYSB20170012);冻土工程国家重点实验室自主研究项目(SKLFSE-ZY-16);国家电网公司科技项目(SGQHDKYOSBJS201600077)资助。

摘　　要：为研究温度和围压对风化花岗岩抗压强度、剪切强度参数及变形特性的影响规律,以新疆天山某一矿区的风化花岗岩为研究对象,对不同温度(15、-5、-15℃)、不同围压(0、4、7、10MPa)条件下的饱水风化花岗岩进行单轴和三轴压缩试验。结果表明:相同温度条件下,围压在0~10MPa变化时,风化花岗岩三轴抗压强度随围压线性增大。在相同围压下,抗压强度随温度的降低而明显提高,风化花岗岩的黏聚力c随温度降低而增大,内摩擦角φ随温度的降低呈增长趋势。弹性模量随围压的增大不断提高,但随着温度的降低,增长幅度逐渐减小。泊松比也随温度降低和围压的增加呈增大趋势。温度和围压对风化花岗岩试样的破坏形态影响机制不同。温度降低使矿物颗粒及内部的微裂纹和间隙收缩,进而胶结强度增大;荷载和围压的增大会使岩石内部形成微裂隙并逐渐贯通,同时孔隙冰破碎裂隙充分接触,进一步增加摩擦力提高岩石强度。To investigate the influence of confining pressure and temperature on strength of rock,a series of uniaxial and triaxial compression tests were conducted on weathered granite at different temperatures(15,-5,-15℃)and confining pressures(0,4,7,10 MPa). Results show that:(1)When the confining pressures range from0 to10 MPa,the triaxial compressive strength of weathered granite increased linearly under the same temperature. Under the same confining pressure,the compressive strength of weathered granite increased obviously as the temperature decreases. Meanwhile,the cohesion increased with the temperature decreasing,the internal friction angle also increased with the temperature decreasing.(2)The modulus of elasticity increased with the increase of confining pressure. However,with the decrease of temperature,the increasing range decreases gradually. Poisson’s ratio increased with the decrease of temperature and the increase of confining pressure.(3)Temperature and confining pressure are important factors affecting failure modes of weathered granite samples.The shrinkage of microcracks and interstices in mineral particles leads to the increase of cementation strength when the temperature decreases. With the increase of confining pressure and loading,micro-cracks developed and penetrated gradually. At the same time,pore ice fractured cracks were fully contacted,the friction force was further increased and the rock strength was improved.

关 键 词：岩石力学 温度 风化花岗岩 强度 力学特性 

分 类 号：TU45[建筑科学—岩土工程]