原状与重塑黄土抗拉强度差异性研究  

The Diversity of Tensile Strength Between Undisturbed Loess and Remolded Loess

作　　者：吴旭阳 梁庆国[2] 罗从双[1] 李春清 王丽丽[4] Wu Xuyang;Liang Qingguo;Luo Congshuang;Li Chunqing;Wang Lili(School of Civil and Transportation Engineering,Henan University of Urban Construction,Pingding shan,Henan 467036,P.R.China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,P.R.China;School of Architectural Engineerings Qinghai Nationalities University,Xining 810007,P.R.China;Key Laboratory of Loess Earthquake Engineering,Lanzhou Institute of Seismology,CEA,Lanzhou 730070,P.R.China)

机构地区：[1]河南城建学院土木与交通运输学院,河南平顶山467036 [2]兰州交通大学土木工程学院,兰州730070 [3]青海民族大学建筑工程学院,西宁810007 [4]中国地震局兰州地震研究所黄土地震工程重点实验室,兰州730070

出　　处：《地下空间与工程学报》2020年第5期1362-1370,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(41562013);河南省科技攻关项目(172102310459);中国地震局地震预测所基本科研业务费专项(2016IESLZ04)。

摘　　要：轴向压裂法是一种间接测定土体抗拉强度的试验方法,本文通过该法分析了原状黄土抗拉变形破坏的一般规律以及试样破坏类型。探讨了原状与重塑黄土的劈裂角以及在强度参数比方面(无侧限抗压强度与抗拉强度比以及粘聚力与抗拉强度比)的差异性。结果表明:原状黄土根据抗拉应力贯入深度曲线走势将变形破坏模式分为3类:弹性变形破坏无残余应力、弹性破坏有残余应力、塑性破坏;原状与重塑黄土在强度参数比方面也存在较大差异。另外,原状黄土劈裂角(α)略小于重塑黄土且均与内摩擦角(φ)呈互补关系;抗拉强度计算公式中的系数K=tan(2α+φ)对于原状黄土建议取值为1.5,对重塑黄土建议取值为2.0。The unconfined penetration test(UP test) is one of the indirect methods to measure the tensile strength of soils. This paper is to study the general regular of samples failure and samples failure types about undisturbed loess by that method. The results indicated that the tensile failure of undisturbed loess can be classified into 3 types: type1,elastic deformation and failure,no have residual stress. Type 2,elastic deformation and has residual stress. Type 3,plastic deformation. The tensile strength formula after modified can apply to loess,and the correction coefficients have big diversity between remolded loess and undisturbed loess. The split angle(α) of undisturbed loess is smaller than that of remolded loess,and the split angle(α) is increase with the internal friction angle(φ) decrease. The suggestion value of correction coefficient K = 2α+φ of undisturbed loess is taken 1.5,and that of remolded loess is taken 2.0.

关 键 词：黄土 抗拉强度 变形破坏 修正系数 

分 类 号：TU45[建筑科学—岩土工程]