兰州Q_4黄土力学性质的各向异性初探  

Preliminary Research on Anisotropy of Mechanical Properties of Q_4 Loess in Lanzhou

作　　者：安亚芳[1] 梁庆国[1] 赵磊[1] 张延杰[1] 

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《兰州交通大学学报》2011年第1期90-96,共7页Journal of Lanzhou Jiaotong University

基　　金：铁道部科技研究开发计划课题资助项目(2005K001-D(G)-1);兰州交通大学"青蓝"人才工程基金(QL-08-19A)

摘　　要：采用室内固结和直剪试验方法,对兰州Q4黄土分别在水平向和垂直向进行了压缩性、抗剪强度和变形参数的比较研究,以期说明取样的方向性对黄土力学性质的影响.研究结果表明:兰州Q4黄土力学性质呈现较为显著的各向异性,在法向应力较低时,显得尤为明显,随法向应力增高,差异性相对减小.对承受垂直向荷载的地基基础等工程类型而言,用垂直向试样所获得的试验值是合理且偏于安全的,但对于边坡和隧道与地下结构等工程,则应考虑黄土强度参数和变形参数的各向异性.The laboratory consolidation and direct shear tests were carried out to compare the shear strength parameters and deformation parameters of Q4 loess in Lanzhou from horizontal and vertical direction respectively,so as to explain the directivity effect on the mechanical properties of the loess.The results show that the anisotropy of mechanical properties of Q4 loess in Lanzhou is remarkable,especially when the normal stress is lower,but when the normal stress is getting higher,the relative differences between vertical and horizontal samplings are reduced.This has something to do with the structural strength in the vertical and horizontal directions of the loess.For the constructions that undergo the vertical loads such as the foundation,subgrade,and et al,the vertical sampling and relevant values are reasonable and safe,but for the slope,tunnel construction and underground structures,the anisotropy or directivity effect of loess should be carefully considered.

关 键 词：原状黄土 变形参数 抗剪强度参数 垂直方向 水平方向 

分 类 号：TU411[建筑科学—岩土工程]