摘要
为了揭示砂土颗粒级配对抗剪强度及边坡稳定性的影响,并为填方工程与边坡设计提供级配优化准则,采用室内直剪试验测定不同细粒含量砂土的抗剪强度,结合离散元数值模拟分析级配参数对边坡破坏过程的影响,并通过理论解析阐明细粒作用的机理。试验表明,细粒含量对抗剪强度呈非线性影响:当细粒含量为30%时,细颗粒充分填充粗粒骨架孔隙,抗剪强度达峰值;超过30%后,粗粒骨架解体导致强度显著下降。数值模拟结果也显示,当细颗粒含量到达一定值时,边坡的破坏程度达到最小,随着细粒含量的增加,破坏程度也逐渐加剧。细粒含量通过双重路径影响砂土力学行为:低含量时剪胀特性主导,高含量时细颗粒使稳定骨架解体,只有当细颗粒含量达到一定值时,才对工程稳定性最有利。
To reveal the influence of sand particle gradation on shear strength and slope stability,and provide gradation optimization criteria for filling engineering and slope design,this study measures the shear strength of sands with different fine-grain contents through indoor direct shear tests,analyzes the influence of gradation parameters on slope failure processes by combining discrete element numerical simulation,and expounds the mechanism of fine-grain action through theoretical analysis.The test results show that the influence of fine-grain content on shear strength is nonlinear:when the fine-grain content is 30%,fine particles fully fill the pores of the coarse-grain skeleton,and the shear strength reaches the peak;when it exceeds 30%,the disintegration of the coarse-grain skeleton leads to a significant decrease in strength.Numerical simulation results also show that when the fine-grain content reaches a certain value,the failure degree of the slope is minimized,and with the increase of fine-grain content,the failure degree gradually intensifies.The fine-grain content affects the mechanical behavior of sand through a dual path:dilatancy characteristics dominate at low contents,while fine particles disintegrate the stable skeleton at high contents.Only when the fine-grain content reaches a certain value is it most beneficial to engineering stability.
作者
崔加林
李志
Cui Jialin;Li Zhi(China Building Technology Group Corporation,Beijing 100013)
出处
《现代工程科技》
2025年第11期105-108,共4页
Modern Engineering Technology
关键词
砂土
级配
抗剪强度
边坡稳定性
sand
gradation
shear strength
slope stability
fine-grain content
discrete element simulation
