三峡库区巫山县老林场高填方边坡稳定性分析  

Stability Analysis of High Fill Slope of Laolinchang in Wushan County,Three Gorges Reservoir Area

作　　者：孙康 张浪 蒋根 杨开 肖诗荣[1] SUN Kang;ZHANG Lang;JIANG Gen;YANG Kai;XIAO Shirong(College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,China;China Railway 11th Bureau Group Sixth Engineering Co.,Ltd.,Xiangyang 441000,China)

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002 [2]中铁第十一局集团第六工程有限公司,湖北襄阳441000

出　　处：《三峡大学学报（自然科学版）》2024年第5期33-40,共8页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(41272310)。

摘　　要：高填方边坡稳定问题是岩土工程界研究的一个热点问题,而回填土物理力学指标的确定是其中一个主要难点.本文以巫山县新城区老林场高填方边坡为研究对象,在边坡地质模型研究的基础上,通过原位重(Ⅱ)型动力触探、室内大型三轴试验以及反演分析,对边坡回填土抗剪强度参数进行了分析研究,从稳定性系数和位移两方面进行了边坡稳定性计算分析.研究认为:边坡压实碎石土,属粗粒土,黏聚力为零;土体摩擦角具有围压效应,随围压增加而降低,本边坡基覆面处回填土摩擦角较浅表部低2°左右;重(Ⅱ)型动力触探成果(40°)为摩擦角上限值,反演分析结果(32°)为其下限值,大型三轴实验成果(38.3°)为其基本值;刚体极限平衡分析表明,边坡整体稳定性好,稳定性系数均大于1.35;局部稳定性计算结果是除中段边坡饱和工况稳定性系数为1.245略低于1.35外,其余部分稳定性系数均大于1.35;FLAC3D模拟揭示,边坡中段坡体位移较大,最大总位移达13.19cm,最大水平位移达12.36cm,但未超出粗粒土边坡的一般容许位移经验值20cm,边坡稳定性较好;表层和浅表层失稳可能是边坡的主要失稳模式,建议采取护坡措施.本研究对同类高填方边坡具有一定参考价值与借鉴意义.The stability of high fill slope is a hot topic in geotechnical engineering field,and the determination of physical and mechanical index of backfill is one of the main difficulties.In this paper,the high fill slope of Laolinchang in the new district of Wushan County is taken as the research object.Based on the geological model of the slope,the shear strength parameters of the backfill soil of the slope are analyzed and studied through in-situ heavy(II)dynamic penetration,indoor large-scale triaxial test and inversion analysis.The stability of the slope is calculated and analyzed from two aspects:stability coefficient and displacement.The results show that:the compacted gravel soil of the slope belongs to coarse-grained soil with zero cohesion;The friction angle of soil has the confining pressure effect and decreases with the increase of confining pressure.The friction angle of backfill soil in the slope bottom base is about 2°lower than that on the shallow surface;The result of heavy(II)dynamic penetration test is the upper limit of friction angle(40°),the result of inversion analysis(32°)is its lower limit,and the result of large-scale triaxial experiment(38.3°)is its basic value;The rigid body limit equilibrium analysis shows that the stability coefficients are greater than 1.35,which means that the overall stability of the slope is good;The local stability calculation results show that the stability coefficient of the slope in the middle section is 1.245,which is slightly lower than 1.35;FLAC-3D simulation reveals that the maximum of total displacement in the middle part of the slope is 13.19 cm,and the maximum of horizontal displacement is 12.36 cm,but it does not exceed the empirical allowable displacement value of 20cm for soil slopes,which means that the slope is stable;Surface and shallow sliding may be the main instability mode of the slope,and slope protection measures are recommended.This paper has certain reference value for similar high fill soil slopes.

关 键 词：三峡库区 高填方边坡 碎石土 摩擦角 三轴试验 稳定性分析 

分 类 号：TU43[建筑科学—岩土工程]