摘要
在边坡稳定性评价中,不同形态、连通率及排列方式的岩桥起决定性作用。本文通过开展室内直剪实验并结合声发射特征参数的研究,揭示了不同连通率岩桥和不同法向应力状态下断续节理岩体的破坏规律。结果表明:在直剪条件下,随法向应力及连通率的变化,岩体破坏面呈现"一"、"X"、"锯齿"、"Z"以及复合型破坏,破坏面起伏度较小,且贯通破坏无时间先后性。法向压力一定时,随着断续岩桥连通率的提高,声发射事件累计计数峰值呈线性增长,计数峰值不断趋于增长。在岩桥连通率一定的情况下,随法向应力的增大,声发射事件计数峰值与累计计数在中等法向应力下最大。对断续节理岩桥变形破坏特征的研究,有利于分析节理岩体的力学特性,有助于边坡工程的稳定性评价与预测。
Rock bridges with different shapes,connectivity rates and arrangements,play a decisive role during slope stability evaluation. Indoor direct shear test combined with the characteristic parameters of acoustic emission is carried out. The test results reveal the failure law of rock mass containing intermittent joints with different connectivity rates and different normal stress states.The results show that： under the condition of direct shear,with the changes of normal stress and connectivity rate,failure surfaces of rock mass appear as ＂A-line-shaped＂,＂Xshaped＂,＂serration-shaped＂,＂Z-shaped ＂ and their combinations, which are somewhat smooth. The crack coalescences of rock mass resulting in failure happen at the same time. When normal stress is constant,with the increase of connectivity rate in intermittent rock bridges,AE cumulative counts grow linearly,while the peak value of AE counts increases generally. When the connectivity rate is constant,with the improvement of normal stress,the peak values of AE counts and AE cumulative counts both reach their peaks under the middle normal stress.Study on the failure and deformation characteristics of rock bridges with intermittent joints is not only useful to theanalysis of the mechanical properties of rock mass,but also is good to the evaluation and prediction in slope engineering.
出处
《工程地质学报》
CSCD
北大核心
2017年第2期322-329,共8页
Journal of Engineering Geology
基金
国家重点基础研究发展计划(973)项目(2013CB733202)
国家自然科学基金项目(41130745
41272330
41572283)资助
关键词
断续节理
连通率
直剪试验
破坏特征
声发射
Intermittent joints
Connectivity rate
Direct shear test
Failure characteristics
Acoustic emission
