基于圆弧-平面组合滑动模式的路基土质边坡浅层稳定分析Stability analysis on subgrade soil-slope in accordance with arc-plane composite failure mode
连继峰,罗强,张文生,谢宏伟,古松
摘要(Abstract):
为了合理评估降雨诱发的路基土质边坡浅层稳定性,针对路基边坡浅层稳定分析简化法在滑体端部抗力计算方面存在的局限性,开展了由滑体上缘张拉区和下缘挤压区为异心圆弧面、中段主滑区为顺坡平面的"圆弧-平面"组合滑动模式分析。基于边坡"圆弧-平面"组合滑面几何方程和滑体静力平衡方程及刚体极限平衡条件,推导了饱和渗流条件下的路基土质边坡浅层安全系数积分表达式,并结合实例工点验证了该方法的可靠性。结果表明:路基边坡浅层"圆弧-平面"失稳模式下,土体抗剪强度参数的获取应与低应力水平相适应;若直接套用与应力水平不相符的常规压力段抗剪强度参数,结果将高估安全系数达2. 5倍以上。该方法有效地解决了传统分析方法力学上的弊端,与有限元法计算结果基本吻合,但较有限元法简单实用,能直观反映参数间变化对安全系数的影响规律,具有一定的工程应用价值。
关键词(KeyWords): 路基土质边坡;浅层失稳;破坏模式;渗流;稳定性分析;滑坡地质灾害;无限长斜坡法;交通运输安全隐患
基金项目(Foundation): 西南科技大学科研基金项目(17zx7152);; 国家自然科学基金项目(51878560);; 四川省科技计划项目(2017GZ0372)
作者(Author): 连继峰,罗强,张文生,谢宏伟,古松
DOI: 10.13928/j.cnki.wrahe.2019.01.003
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