考虑滑带土蠕变特性的边坡长期稳定性分析  

Long-term Stability Analysis of Slope Considering Creep Behaviors of Sliding Zone Soils

作　　者：古鹏翔 骆俊晖 刘先林 马冲[3] GU Pengxiang;LUO Junhui;LIU Xianlin;MA Chong(Guangxi Yanglu Highway Co.,Ltd.,Nanning 530021,China;Guangxi CommunicationDesign Group Co.,Ltd.,Nanning 530029,China;School of Mathematics and Physics,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]广西阳鹿高速公路有限公司,广西南宁530021 [2]广西交通设计集团有限公司,广西南宁530029 [3]中国地质大学数学与物理学院,湖北武汉430074

出　　处：《安全与环境工程》2020年第4期94-101,共8页Safety and Environmental Engineering

基　　金：广西交通科技项目(20140203)。

摘　　要：为明确边坡软弱夹层中滑带土的蠕变特性对边坡长期稳定性的影响,选取某典型岩质边坡工程为实例,首先在查找、分析已有滑坡事故发生原因的基础上,通过现场监测和室内环剪试验,研究了不同含水量和法向应力条件下边坡滑带土的蠕变变形曲线特征;然后通过引入有关损伤变量的经验关系式,建立了考虑含水量变化的用于描述边坡滑带土蠕变非线性蠕变本构模型;最后将模型计算结果与实测结果进行对比,验证所建立模型的有效性和正确性,并通过预测一年后边坡软弱夹层变形的发展规律,对该边坡长期稳定性做出评价,探讨了计算模型对于外部环境因素影响的局限性。结果表明:①边坡滑带土的蠕变特性与含水量密切相关,引入的损伤变量经验关系式可以有效地描述这一特性;②基于边坡滑带土蠕变特性的应力-应变计算模型,可以准确、有效地评价边坡软弱夹层的变形情况;③边坡软弱夹层的塑性剪切变形随时间的推移呈不断增加趋势,其累积变形量逐渐贯通于整个软弱面,最终导致滑坡的发生;④计算模型中未考虑自然条件的影响,在强烈自然环境的作用下,应加强边坡变形的实时监控,并与模型计算结果进行对比与分析,针对异常情况,及时采取合理的工程防护措施。该研究结果可为此类边坡的长期安全评价提供理论指导。In order to clear the effect of creep behaviors of sliding zone soils in slope soft interlayer on the long-term stability of slope,by selecting a typical rock slope as the engineering example,and on the basis of finding and analyzing the reasons for the slope failure,this paper conducts both the field monitoring and the laboratory ring shear tests to investigate the characteristics of the creep deformation curves of sliding zone soils with different moisture content and normal stress.Then through introducing the empirical relationship of damage variables,the paper develops a non-linear creep constitutive model describing the creep behaviors of sliding zone soils of slope considering variation in moisture content.Next,the paper compares the calculated results with measured results to verify the validity and correctness of the proposed model.Furthermore,the paper predicts the evolution of soft interlayer deformation in the next year,evaluates the long-term stability of the slope,and discusses the limitation of the model in extenal environmental factors.The results show that①creep behaviors of soft interlayer are closely related to the magnitude of moisture content,which can be well described by the introduced empirical relationship of damage variable;②the calculation model of stress-strain with incorporating creep behaviors of sliding zone soils could yield an accurate and valid prediction result of deformation of the soft interlayer;③the elastic shear deformation of soft interlayer increases with monitoring time and its accumulated deformation will gradually penetrate the whole soft interlayer,which eventually leads to the occurrence of slope failure;④the influence of natural conditions is not incorporated in the calculation model.Thus,the real-time monitoring work should be reinforced,and comparison and analysis should be conducted with the model calculation results,and reasonable engineering protection measures should be carried out in time in view of abnormal situations.The paper provides theoretical gu

关 键 词：滑带土 蠕变特征 边坡 长期稳定性 室内环剪试验 本构模型 

分 类 号：X45[环境科学与工程—灾害防治] P642.22[天文地球—工程地质学]