摘要
当前工程设计都是将边坡失稳破坏看成整体的剪切破坏即M—C剪切破坏，基本不考虑岩土体本身抗拉强度。而岩质边坡真实的破坏应该是张拉-剪切复合破坏，不应是传统不考虑抗拉强度的单一剪切破坏模式。利用FLAC^3D软件，基于张拉-剪切复合破坏准则对岩体和结构面强度参数同时进行强度折减，与只考虑抗剪强度的情况进行比较来研究抗拉强度对岩质边坡稳定性的影响。分析结果表明，考虑抗拉强度条件的边坡稳定系数大多比没考虑抗拉强度的稳定系数大，而后者的稳定性对结构面倾角的敏感性更高。复合破坏准则下，边坡破坏过程都是先从坡脚出现剪切滑移带并向上发展，此后坡项某深度范围内出现张拉塑性区，两者贯通时整个边坡将处于失稳破坏临界状态。
At present,it is always considered that unstable slopes are simply caused by shear failure （the failure of Mohr-Coulomb shear） ,but without the tensile strength of rock-soil mass. However ,the true failure mode is composed of both tension and shear failure. Based on the composite failure criterion of tension and shear, FLAC^3D software is used to analyze the strength reduction of tension and shear at the same time, and then the result is taken to research the effect on the rock slope stability by comparing with the one without considering shear strength. According to the conclusion, the slope stability with considering tension and shear strength is higher than the one without considering tensile strength, and the latter is more sensitive to the slope angle of joint. With the c-φ and tension reduction, the glide band would appear in the toe at first, then tension plastic zone develops on the top of slope, and when the two zones expand to connect with each other, the whole slope would be in critical phase of unstability.
出处
《后勤工程学院学报》
2011年第6期7-12,共6页
Journal of Logistical Engineering University
基金
重庆市自然科学基金资助项目(2010BC8002)
关键词
岩质边坡
张拉-剪切
破坏准则
塑性区
rock slope
tension and shear
failure criterion
plastic zone
