巴东组泥岩重塑土在不同初始含水率条件下强度及膨胀特性研究  

Study on strength and swelling characteristics of mudstone remolded soil in Badong Formation under different initial water contents

作　　者：赵二平[1] 车德龙 张聪 蒋尚家 向国梁 刘士元 ZHAO Erping;CHE Delong;ZHANG Cong;JIANG Shangjia;XIANG Guoliang;LIU Shiyuan(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学防灾减灾湖北省重点实验室,湖北宜昌443002

出　　处：《四川建筑科学研究》2023年第6期75-82,共8页Sichuan Building Science

基　　金：国家自然科学基金项目(U2034203)。

摘　　要：泥岩在中国分布广泛,遇水后易膨胀、软化,对工程有很大的潜在危害。以郑万高铁沿线巴东组泥岩重塑土为研究对象,开展了不同初始含水率的泥岩重塑土强度及膨胀特性试验研究。结果表明:泥岩重塑土抗剪强度随着法向应力增大而线性增大,用Culomb公式拟合较好;泥岩重塑土黏聚力和内摩擦角均随着初始含水率的增大而减小;泥岩重塑土膨胀率随着初始含水率的增大而迅速减小;存在泥岩重塑土膨胀率为0时的临界含水率wcr,wcr处于土体塑限含水率wp±3.50%范围内,表明泥岩内部强结合水的厚度即双电层中的固定层控制着泥岩膨胀变形。Mudstone is widely distributed in China,which is easy to expand and soften after encountering water,causing potential risks and hazards of engineering.Taking mudstone remolded soil of Badong Formation along Zhengzhou-Wanzhou high-speed railway as the research object,the strength and swelling characteristics of mudstone remolded soil with different initial water contents were studied experimentally.The results show that the shear strength of mudstone remolded soil increases linearly with the increase of normal stress,which can be well fitted by Culomb formula.The cohesion and the internal friction angle of mudstone remolded soil decrease with the increase of initial water content.The expansion ratio of mudstone remolded soil decreases rapidly with the increase of initial water content.There is a critical value wcr of water content when the expansion rate of mudstone remolded soil is 0,the wcr is in the±3.50%range of wp of soil plastic limit water content.It shows that the thickness of the absorption water inside the mudstone,that is,the fixed layer in the double electric layer,controls the swelling deformation of the mudstone.

关 键 词：泥岩 初始含水率 临界含水率 膨胀特性 

分 类 号：TU433[建筑科学—岩土工程]