季节性冻融过程黄土斜坡失稳机制及稳定性趋势  

Instability mechanism and stability trend of loess slope during seasonal Freeze-thaw process

作　　者：曾磊[1,2] 贾俊 ZENG Lei;JIA Jun(Xi'an Center,CGS,Xi'an 710054,Shaanxi,China;Key Laboratory of Loess Geological Hazards,Ministry of Natural Resources,Xi'an 710054,Shaanxi,China)

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054 [2]自然资源部黄土地质灾害重点实验室,陕西西安710054

出　　处：《地质通报》2022年第8期1494-1503,共10页Geological Bulletin of China

基　　金：国家自然科学基金项目《冻融交替下黄土斜坡水文循环机理及对斜坡稳定性影响研究》(批准号:41202178)。

摘　　要：季节性冻融型滑坡是黄土地质灾害的主要类型之一。季节性冻融过程中地下水响应极其敏感,地下水分布和变化对黄土斜坡体内岩土体的应力状态、力学性状及斜坡稳定性均有较大的影响,冻结期滞水与融解期疏水引发的斜坡范围内地下水位变化是黄土斜坡稳定性变化及失稳破坏的主要诱发因素之一。在季节性冻融过程斜坡地下水变化全过程分析基础上,采用基于极限平衡理论的条分法和基于弹塑性理论的有限元数值法,对黄土斜坡稳定性与斜坡应力应变场的响应进行分析计算,探讨季节性冻融条件下黄土斜失稳破坏机制及稳定性变化趋势,认为黄土斜坡在冻融过程中的稳定性状态与冻结融解日期呈现明显滞后效应,其失稳状态将持续至融解中期,为季节性冻融型滑坡预警防治提供科学依据。Seasonal freeze-thaw landslides are one of the main types of loess disasters.The groundwater response is extremely sensitive during seasonal freezing and thawing.The distribution and changes of groundwater level have a greater impact on the stress state,mechanical properties and slope stability of the rock and soil in the loess slope.Slope caused by stagnant water during freezing and draining during thawing.The change of groundwater level within the scope is one of the main inducing factors for the stability change and instability of the loess slope.Based on the whole process of slope groundwater change during seasonal freezing and thawing,this paper adopts the slice method based on limit equilibrium theory and the finite element numerical method based on elastoplastic theory to analyze and calculate the slope stability and slope stress and strain field response.Under seasonal freezing and thawing conditions,the failure mechanism and stability change trend of the slope of loess slopes.Provide scientific basis for early warning and prevention of seasonal freeze-thaw landslides.

关 键 词：季节性冻融 黄土斜坡 稳定性 数值模拟 

分 类 号：P694[天文地球—地质学] P642.2