| 甘肃定西原状Q_3黄土各向异性试验研究 |
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| 引用本文： | 徐善常,梁庆国,李帅帅,张堂杰,张荣.甘肃定西原状Q_3黄土各向异性试验研究[J].地质力学学报,2015,21(3):378-385. |
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| 作者姓名： | 徐善常 梁庆国 李帅帅 张堂杰 张荣 |
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| 作者单位： | 甘肃省道路桥梁与地下工程重点实验室, 兰州 730070;兰州交通大学土木工程学院, 兰州 730070;甘肃省道路桥梁与地下工程重点实验室, 兰州 730070;兰州交通大学土木工程学院, 兰州 730070;甘肃省道路桥梁与地下工程重点实验室, 兰州 730070;兰州交通大学土木工程学院, 兰州 730070;甘肃省道路桥梁与地下工程重点实验室, 兰州 730070;兰州交通大学土木工程学院, 兰州 730070;甘肃省道路桥梁与地下工程重点实验室, 兰州 730070;兰州交通大学土木工程学院, 兰州 730070 |
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| 基金项目： | 国家自然科学基金项目(41262010);长江学者和创新团队发展计划项目(IRT1139);兰州交通大学“青蓝”人才工程项目(QL-08-19A);甘肃省基础研究创新群体资助项目(145RJIA332) |
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| 摘 要： | 通过室内三轴试验,研究了甘肃定西原状Q3黄土的各向异性对于黄土抗剪强度和变形参数的影响。研究结果表明,此种黄土的各向异性对土体力学性质的影响显著。垂直向原状黄土抗剪强度明显高于水平向,随着围压的增大,二者之差明显下降,最终稳定在10%的差值范围内。围压小于100 k Pa时,水平向破坏应变明显大于垂直向,且随着围压逐渐增大二者差值逐渐减小,并在围压高于200 k Pa时,破坏应变达到一致。利用邓肯-张模型对偏差应力实测值与计算值进行差值分析表明,低应变处垂直向与水平向的差值均较大;随着围压增大,差值逐渐减小并最终稳定在±5%差值范围内,且最大偏差应力均符合误差为±5%的范围。无论是垂直样还是水平样,大约在2%应变之前的应力应变曲线都近似为回归系数很高的线性关系,可近似估算不同方向黄土的变形模量,其值分别为130 MPa和85 MPa。
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| 关 键 词： | 原状黄土 各向异性 破坏应力 破坏应变 变形模量 |
| 收稿时间： | 2014/12/1 0:00:00 |
EXPERIMENTAL STUDY ON ANISOTROPIC CHARACTERISTICS OF UNDISTURBED Q3 LOESS FROM DINGXI, GANSU |
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| XU Shan-chang,LIANG Qing-guo,LI Shuai-shuai,ZHANG Tang-jie and ZHANG Rong.EXPERIMENTAL STUDY ON ANISOTROPIC CHARACTERISTICS OF UNDISTURBED Q3 LOESS FROM DINGXI, GANSU[J].Journal of Geomechanics,2015,21(3):378-385. |
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| Authors: | XU Shan-chang LIANG Qing-guo LI Shuai-shuai ZHANG Tang-jie and ZHANG Rong |
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| Institution: | Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou 730070, China;College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou 730070, China;College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou 730070, China;College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou 730070, China;College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou 730070, China;College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China |
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| Abstract: | Through the triaxial test in the laboratory, the anisotropy effect of Q3 loess from Dingxi, Gansu on the shear strength and deformation parameters was studied. The results show that the anisotropy of undisturbed Q3 loess has obvious influence on its mechanical properties. The shear strength in vertical direction of the loess is much higher than that in horizontal direction, and with the increase of the confining pressures, the difference between the shearing strengths of the two directions decreases significantly and eventually stabilizes within an error of 10%. When the confining pressure is lower than 100 kPa, the failure strain of the loess in horizontal direction is higher than that in vertical direction, and the difference between the failure strains of the two directions gradually decreases with the confining pressure increases. When the confining pressure is higher than 200 kPa, the failure strains in vertical and horizontal directions tend to be the same. By using Duncan-Chang model, the measured and the calculated deviatoric stresses are compared which indicate that the difference between the vertical direction and the horizontal direction is large in the low strain range, and with the confining pressure increasing, the difference gradually decreases and stabilizes in the error range of 5%. The stress strain curves of the loess samples in both the vertical and horizontal directions show linear relationship with very high regression coefficients when the strain is less than 2%, which can be used to approximately calculate the deformation modulus of the loess samples in both directions, and the corresponding values are 130 MPa and 85 MPa respectively. |
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| Keywords: | undisturbed loess anisotropy failure stress failure strain deformation modulus |
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