摘要
为了解降雨过程中非饱和土质边坡结构的变化规律,基于有限元数值计算方法和非饱和土体力学特征关系理论,探讨了在不同降雨工况作用下某实际工程项目的边坡渗流过程与坡体内力分布的耦合特性,归纳了降雨过程中边坡内土体饱和度变化、孔隙水压力分布以及土体塑性区分布随降雨时长变化规律。结果表明,1)降雨初期边坡表面土体的饱和度和孔隙压力变化较为迅速,随着降雨过程的持续进行,坡体中非饱和土体的容重和饱和度不断增加;2)在土体饱和度和容重增加的同时,土体的渗透系数与渗流状态也发生显著改变,容易在坡脚渗出点位置造成局部塑性破坏区以及侵蚀破坏,从而降低结构的整体安全性;3)当降雨强度大于土体下渗速度时,会在坡体表面形成径流,从而引起表面侵蚀破坏,因此建议对于强降雨地区,应设计坡体表面排水通道。研究结果为强降雨地区的边坡结构加固以及排水设计提供了依据,可以为已有边坡工程的评估与改造提供参考。
In order to understand the change rules of unsaturated soil slope structure under rainfall conditions,based on the finite element numerical calculation method and the mechanical theory of the characteristics of unsaturated soil,the coupling characteristics of the slope seepage process and the internal force distribution of a practical project under different rainfall conditions were discussed.The change rules of the soil saturation,the pore water pressure distribution and the soil plastic zone distribution with the rainfall duration were summarized.The results show that:1)The saturation and pore pressure of the soil change rapidly at the initial stage of rainfall,and the bulk density and saturation of the unsaturated soil in the slope increase with the continuous rainfall process;2)With the increase of soil saturation and bulk density,the permeability coefficient and seepage state of the soil also change significantly,which is easy to cause local plastic failure area of the slope toe accompanied by erosion failure,so as to reduce the overall safety of the slope.3)When the rainfall intensity is greater than the infiltration speed of the soil,the runoff will be formed on the surface of slope,which will cause surface erosion damage.Therefore,it is suggested that the drainage channel on the slope surface should be designed in areas with heavy rainfall.The research results not only offer the basis for the structural reinforcement and drainage design of the slope in heavy rainfall areas,but also provide reference for the evaluation and reconstruction of the existing slope engineering.
作者
周娟
朱峰
ZHOU Juan;ZHU Feng(CCCC Regional Headquarters in Guangdong-Hong Kong-Macao Greater Bay Area,Guangzhou,Guangdong 510623,China;CCCC-FHDI Engineering Company Limited,Guangzhou,Guangdong 510230,China)
出处
《河北工业科技》
CAS
2020年第4期273-279,共7页
Hebei Journal of Industrial Science and Technology
基金
国家自然科学基金(51909182)。
关键词
岩土工程
非饱和渗流
渗流-应力耦合
数值分析
黏性土
geotechnical engineering
unsaturated seepage
seepage-stress coupling
numerical analysis
clayey soil
