高拱坝坝肩软弱结构面HM耦合效应试验研究

发布时间：2018-11-12 18:25

【摘要】：为定量揭示高拱坝工程蓄水运行后,坝肩岩体中软弱结构面在HM(Hydro-Mechanical)耦合作用下的弱化效应,结合锦屏一级高拱坝工程,现场采集该拱坝坝肩主要断层的原样,用重塑试样方法制备试件,在MTS岩石力学试验系统上开展不同水压(0,1,2,3,4 MPa)情况下的系列三轴压缩试验。结果表明:断层物质的强度参数具有显著的水压弱化效应,其中强度参数f随水压的升高弱化不大,各断层的平均弱化率不超过7%;强度参数c随水压的升高急剧减小,最大弱化率可达100%;考虑两者的综合效应抗剪强度τ,在3 MPa水压与10MPa正应力的工程条件下,各断层抗剪强度的平均弱化率约为25%。同时,建立了不同渗透水压力条件下结构面强度参数预测模型,并采用有效应力原理对结构面抗剪强度的弱化规律和机理进行初步分析。试验成果已应用于锦屏一级拱坝坝肩稳定性研究,研究方法可供多场耦合作用下软弱结构面的力学性能研究参考。
[Abstract]:In order to reveal quantitatively the weakening effect of weak structural plane in the abutment rock mass under the coupling action of HM (Hydro-Mechanical) after the water storage operation of the high arch dam project, the original samples of the main faults of the abutment of the arch dam are collected on the spot in combination with the Jinping first grade high arch dam project. A series of triaxial compression tests were carried out on MTS rock mechanics test system under different water pressure (0 1 ~ 2 ~ 2 ~ 3 ~ 3 ~ 4 MPa) by remolded specimen method, and a series of triaxial compression tests were carried out in this paper. The results show that the strength parameter of fault material has obvious water pressure weakening effect, in which the strength parameter f is not weakened with the increase of water pressure, and the average weakening rate of each fault is less than 7. The strength parameter c decreases sharply with the increase of water pressure, and the maximum weakening rate can reach 100. Considering the comprehensive effect of the two factors, the average weakening rate of shear strength of each fault is about 25 under the engineering condition of 3 MPa water pressure and 10MPa normal stress. At the same time, the prediction model of structural surface strength parameters under different permeable water pressure is established, and the weakening law and mechanism of shear strength of structural plane are analyzed with the effective stress principle. The experimental results have been applied to the study of dam abutment stability of Jinping first class arch dam. The research method can be used as a reference for the study of mechanical properties of weak structural plane under multi-field coupling.
【作者单位】：四川大学水力学与山区河流开发保护国家重点实验室水利水电学院;诺丁汉大学诺丁汉岩土力学中心工程学院;
【基金】：国家自然科学基金项目(51609163;51409179;51379139) 国家重点研发项目(2016YFC0401908)资助
【分类号】：TV642.4

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