摘要
降雨入渗对边坡稳定性具有重要影响。鉴于层状边坡在自然情况中广泛存在,因此,开展在降雨情况下的多层状边坡入渗模型及其稳定性研究具有重要意义。考虑各层土体的渗透性能差异,利用约束函数求得各层土体的有效渗透系数,并基于Green-Ampt模型建立层状边坡入渗模型。结合非饱和土强度经验公式,推导了考虑滑面抗剪强度动态变化的层状边坡稳定性方程。最后,对深圳某边坡在不同降雨强度和降雨历时下的稳定性系数进行了计算并对结果进行了分析。结果表明,当湿润锋未达到滑面处时,边坡稳定性系数与降雨历时和降雨强度呈线性关系。考虑边坡入渗能力,提出了降雨入渗临界时间概念。在任意降雨强度下,当降雨历时小于该时间时,边坡均不会失稳。本研究可以用于指导降雨情况下层状边坡的稳定性评价。
Rainfall infiltration has a significant effect on slope stability.It is meaningful to study the infiltration model and stability of layered slopes under rainfall in view of the wide distribution of layered slopes in nature environment.Because of the difference of permeability coefficient of soil layer,the effective permeability coefficient of each layer is obtained via constraint function and the infiltration model of layered slope is derived based on the Green-Ampt model.Based on the empirical formula of unsaturated soil strength,the equations for calculating the stability of layered slopes are proposed with consideration of variation of shear strength of slip surface.Finally,the stability coefficient of a slope in Shenzhen,China under different rainfall intensity and rainfall duration is illustrated and the results are analyzed.The analysis indicates that slope stability coefficient is linearly related to rainfall duration and rainfall intensity before the wetting front reaches the slip surface.Considering the infiltration capacity of soils,the concept of threshold time in rainfall infiltration is introduced.As long as the rainfall duration is shorter than this threshold time,the slope will not lose its stability in rainfall infiltration.The research can be used to guide the stability evaluation of layered slopes under rainfall.
作者
曾江波
付智勇
肖林超
吴飞飞
姚文敏
Zeng Jiangbo;Fu Zhiyong;Xiao Linchao;Wu Feifei;Yao Wenmin(Shenzhen Geotechnical Investigation ＆ Surveying Institute Co.,Ltd.,Shenzhen Guangdong 518028,China;Faculty of Engineering,China University of Geosciences（Wuhan）,Wuhan 430074,China)
出处
《地质科技情报》
CSCD
北大核心
2018年第4期225-231,共7页
Geological Science and Technology Information
基金
深圳市科技计划技术攻关项目(JSGG20160331154546471)
