考虑前期降雨的边坡稳定降雨阈值曲面

发布时间：2018-02-01 01:42

本文关键词： 降雨阈值力学模型非饱和土边坡前期降雨滑坡预警　出处：《岩土力学》2015年S1期 　论文类型：期刊论文

【摘要】：在经验性降雨阈值和边坡稳定性数值分析两大类研究的基础上,考虑了降雨入渗和非饱和土性质,使用岩土有限元软件Plaxis高级模式对滑坡预警降雨阈值进行研究分析。算例表明,将降雨量在降雨时间范围内分成2段后,得到的边坡稳定性变化与实际情况更接近,重新定义前期降雨为在给定初始条件下引起边坡最危险滑裂面到坡面之间土体吸力分布发生变化的降雨。前期降雨时长与潜在滑裂面最大深度成正比,与饱和渗透系数成反比。将前期降雨量引入到降雨强度—持时曲线中作为第三个空间坐标轴,将该曲线拓展为前期降雨量-降雨强度-持时曲面。通过一基岩型边坡算例展示了阈值曲面的建立方法,并通过与模型试验数据的对比验证了其可靠性。
[Abstract]:Based on empirical rainfall threshold and slope stability numerical analysis, rainfall infiltration and unsaturated soil properties are considered. Using the Plaxis advanced model of geotechnical finite element software, the rainfall threshold of landslide early warning is studied and analyzed. The example shows that the rainfall is divided into two sections in the rainfall time range. The obtained slope stability change is closer to the actual situation. Redefine the pre-rainfall as the rainfall that causes the change of soil suction distribution between the most dangerous slip surface and slope surface under the given initial conditions. The duration of the early rainfall is proportional to the maximum depth of the potential slip surface. It is inversely proportional to the saturation permeability coefficient. The rainfall of the previous period is introduced into the rainfall intensity-duration curve as the third spatial coordinate axis. The curve is extended to a surface of rainfall, rainfall intensity and duration of time. A calculation example of bedrock slope shows the method of establishing threshold surface, and the reliability of the curve is verified by comparison with model test data.
【作者单位】：清华大学土木工程安全与耐久教育部重点实验室;
【基金】：国家重点基础研究发展计划(No.2014CB047004)
【分类号】：TU43
【正文快照】： 1引言降雨是诱发滑坡灾害的主要因素之一,其对边坡稳定性的影响成为近些年来学者关注的热点话题。目前在这方面的研究主要分为两类,一类是根据历史上诱发滑坡的降雨数据建立经验性降雨阈值,作为滑坡预警的依据;另一类是通过试验方法或数值方法研究降雨对边坡稳定性的影响规律,

【参考文献】