摘要
【目标】准确掌握红层泥岩填料变形特性,揭示引发红层地质灾害的诱因。【方法】选取甘肃省某公路试验段的红层泥岩填料为研究对象,开展液塑限试验、击实试验、三轴CU试验和固结试验,探究含水率、围压和压实度对应力-应变曲线、峰值强度和抗剪强度指标的影响,研究邓肯-张模型对应变硬化型曲线的适用性,确定了邓肯-张模型参数和简布提出的初始模量与围压之间的土性参数,根据固结试验得到一维压缩指标,分析其压缩性。【结果】该红层泥岩填料为低液限黏土,随着含水率的增加土体抗剪强度与内摩擦角均呈现明显的劣化现象,邓肯-张模型能够很好地描述红层泥岩填料应变硬化型的应力-应变曲线,选用极限偏差应力作为归一化因子,模型预测结果与试验结果高度吻合,归一化效果极好,同时构建了以极限偏差应力为归一化因子的本构模型。【结论】红层泥岩具有显著的水敏特性,水-力耦合作用下力学性能急剧劣化,不宜直接用作路基填料。研究成果为红层地区地质灾害防治与路基工程优化设计提供了理论依据。
[Objective]The study investigated the deformation characteristics of red mudstone filling,and revealed the triggers of red-bed geological hazards.[Method]The red mudstone fillings obtained from a highway test section in Gansu Province were selected as the study subject.A series of tests was carried,i.e.,liquid-plastic limit test,compaction test,triaxial consolidated undrained test,and consolidation test.The influences of moisture content,confining pressure and compaction degree on stress-strain curves,peak strength,and shear strength were studied.The applicability of Duncan-Chang model to strain-hardening curves was examined.The key parameters of Duncan-Chang model were determined,as well as the soil parameters between initial modulus and confining pressure proposed by Janbu.One-dimensional compression indicators were derived from consolidation tests,and the compressibility was analyzed.[Result]The red mudstone fillings were classified as low liquid limit clay.With moisture content increasing,both shear strength and internal friction angle exhibited significant degradation.The Duncan-Chang model effectively captured the strain-hardening characteristics of stress-strain curves.Using limit deviation stress as a normalization factor,the model prediction result showed excellent agreement with the test result,achieving exceptional normalization.The constitutive model was established with the limit deviation stress as normalization factor.[Conclusion]The red mudstone filling demonstrates significant water-sensitive characteristics.Its mechanical properties deteriorate drastically under hydro-mechanical coupling,and it is not suitable for the direct use as roadbed filling.The findings provide a theoretical foundation for mitigating geological hazards and optimizing roadbed engineering design in red-bed regions.
作者
余云燕
杜乾中
崔文豪
罗崇亮
YU Yunyan;DU Qianzhong;CUI Wenhao;LUO Chongliang(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)
出处
《公路交通科技》
北大核心
2025年第8期72-82,共11页
Journal of Highway and Transportation Research and Development
基金
甘肃省科技计划项目(21YF5GA050)
甘肃省交通运输厅科技研发项目(2021-12)
甘肃省教育厅产业支撑计划项目(2021CYZC-28)。
关键词
道路工程
本构模型
室内试验
红层泥岩填料
归一化
road engineering
constitutive model
laboratory test
red mudstone filling
normalization
