细颗粒粘滑运动的能量耗散与释放试验

发布时间：2018-07-10 20:09

本文选题：钠钙玻璃珠 + 粘滑运动　；参考：《地球科学》2016年09期

【摘要】：近年来,利用断层产物以及其中的颗粒来研究断层或地震带的能量耗散与释放,已引起大家的重视.在围压分别为30kPa、60kPa、100kPa、200kPa、400kPa和600kPa的条件下,采用直径为0.6~0.8mm的玻璃珠以0.02mm/min的轴向应变速率进行干燥、松散细颗粒材料的固结不排水三轴压缩试验.为了减少轴向应变过大时主应力轴旋转产生的误差及其对做功的影响,试验只分析加载后轴向应变为10%时试样变形破坏过程中的能量耗散与能量释放特性.试验结果表明:随着围压的增大,主震频率减小、偏应力降幅增大,但偏应力降幅与最大偏应力的比值逐渐趋于稳定.粘滑运动过程中,在偏应力骤降瞬间,声发射强烈、试样体积收缩,说明能量控制着试样的变形与破坏特征,耗散结构能量越大,系统发生滑动的频率越小.粘滑运动过程可以表示为能量耗散与能量突然释放.最后,从热力学的角度分析滑动过程的3个阶段,得出粘滑运动为不可逆耗散能与可释放应变能共同作用的结果.
[Abstract]:In recent years, the energy dissipation and release of faults or seismic zones have been studied by using fault products and their particles. Under the confining pressure of 30kPa60kPa100kPa200kPa200kPa400kPa and 600kPa, the glass beads with diameter of 0.6~0.8mm were dried at the axial strain rate of 0.02mm/min, and the undrained triaxial compression test of loose fine granular materials was carried out. In order to reduce the error caused by the rotation of the principal stress axis and its influence on the work when the axial strain is too large, the energy dissipation and energy release characteristics during the deformation and failure of the specimen with the axial strain of 10 after loading are analyzed in the experiment. The experimental results show that with the increase of confining pressure, the frequency of the main shock decreases and the deviation stress decreases, but the ratio of the deviation stress to the maximum deflection stress tends to be stable. During the visco-slip movement, the acoustic emission is strong and the sample volume shrinks at the moment of the sudden drop of the deviant stress, which indicates that the energy controls the deformation and failure characteristics of the specimen, and the larger the dissipative structure energy, the smaller the frequency of the system sliding. The process of stick-slip motion can be expressed as energy dissipation and sudden release of energy. Finally, three stages of the sliding process are analyzed from the point of view of thermodynamics, and the result that the viscous slip motion is an irreversible dissipative energy combined with the released strain energy is obtained.
【作者单位】：中国地质大学工程学院;奥地利维也纳农业大学岩土工程所;中国地质大学教育部长江三峡库区地质灾害研究中心;
【基金】：国家自然科学基金项目(Nos.41002102,41272308)
【分类号】：P315

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