直剪剪切方式对崩岗土体边坡稳定性的影响  

Impact of direct shear methods on the stability of Benggang slope

作　　者：李斯萱 张晓明[1] 赵艺 郭晓亮 Li Sixuan;Zhang Xiaoming;Zhao Yi;Guo Xiaoliang(College of Resources and Environment,Huazhong Agricultural University,Wuhan,430070,China;Wuhan Linshui Engineering Consulting Co.,Ltd.,Wuhan,430070,China)

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]武汉林水工程咨询有限公司,武汉430070

出　　处：《水土保持研究》2025年第3期180-187,共8页Research of Soil and Water Conservation

基　　金：国家自然科学基金(41771307;41201271);生产建设项目中水文数据筛选新技术(20212614C03)。

摘　　要：[目的]探究不同直剪方式对崩岗土体抗剪性能及边坡稳定性的差异化影响,旨在为边坡治理提供科学依据。[方法]采用不同直剪试验测量抗剪强度参数,并利用FLAC3D软件模拟各剪切条件下边坡稳定性变化,以综合分析不同直剪方式的力学效应。[结果](1)慢剪条件下剪应力响应最大:红土层在荷载400 kPa下慢剪试验中剪应力激增至197.9 kPa,表明其在慢速剪切下具有高强度增长潜力。(2)剪切强度与剪切方式的敏感性:红土层相比过渡层对剪切方式更为敏感,荷载为400 kPa慢剪下的抗剪强度达到194.547 kPa,高于过渡层的182.37 kPa。固结快剪对土体内部力学属性(如内摩擦角和黏聚力)的改变最为明显。(3)边坡稳定性分析:慢剪不仅安全系数低(FS=3.18),且伴随较大剪应变增量及广泛变形区域,明确其为最不稳定剪切模式。崩岗边坡X轴应力均朝向坡面,最大约为22 kPa,所有剪切方式下位移均初增后减,但固结快剪位移量及方向有别于其他试验,显示位移量较大,方向朝向坡外。Y轴应力随深度增加递减,慢剪下剪应力变幅尤为突出。[结论]在不同的直接剪切方式作用下,抗剪强度的绝对差异虽不显著,但内摩擦角与黏聚力相差较大。经数值模拟分析可知,慢剪条件对崩岗边坡的稳定性构成了最大的挑战。[Objective]This study investigates the differential impact of various direct shear methods on the shear resistance performance of Benggang soil and slope stability,aiming to provide scientific evidence for slope management.[Methods]Different direct shear tests were used to measure shear strength parameters,and FLAC3D software was employed to simulate slope stability changes under various shear conditions for a comprehensive analysis of the mechanical effects of each direct shear method.[Results](1)Maximum shear stress response under slow shear conditions:in the slow shear test,the shear stress in the red soil layer surged to 197.9 kPa under a 400 kPa load,indicating its high potential for strength increase under slow shear conditions.(2)Sensitivity of shear strength to shear methods:the red soil layer is more sensitive to shear methods compared to the transition layer.Under the slow shear test with a 400 kPa load,the shear strength reached 194.547 kPa,higher than the transition layer′s 182.37 kPa.Consolidated quick shear significantly affected the internal mechanical properties of the soil,such as internal friction angle and cohesion.(3)Slope stability analysis:slow shear not only resulted in a low safety factor(FS=3.18),but also led to large shear strain increments and extensive deformation areas,making this shear method the least stable shear method.The X-axis stress on the Benggang slope was directed towards the slope face,peaking at approximately 22 kPa.Displacement under all shear methods initially increased and then decreased.However,the magnitude and direction of displacements in the consolidated quick shear test differed from those in other tests,showing a large displacement towards the outside of the slope.The Y-axis stress decreased with increasing depth,and the shear stress variation was particularly significant under slow shear conditions.[Conclusion]Under different direct shear methods,although the absolute difference in shear strength is not significant,the internal friction angle and cohesion dif

关 键 词：直剪方式 FLAC3 D 稳定性 边坡 崩岗 

分 类 号：S157.1[农业科学—土壤学]