黄土天然节理大型直剪试验研究

发布时间：2018-01-21 15:27

本文关键词： 黄土节理大型直剪试验剪切强度尺寸效应　出处：《西安建筑科技大学学报(自然科学版)》2017年05期 　论文类型：期刊论文

【摘要】：黄土节理的抗剪强度及变形规律对工程稳定性有重要影响,但目前对此的研究尚不充分.为此本次研究首先采集了黄土天然垂直节理土样,然后采用室内大型直剪试验方法,研究了黄土天然节理的剪切强度及变形性质,最后与小型直剪试验结果进行对比,得到了尺寸效应对黄土节理剪切强度的影响规律.结果发现,大型直剪试验得到黄土节理剪切峰值内摩擦角为47.37°,小型直剪试验值为35.17°;黄土节理直剪试验存在尺寸效应,试样尺寸主要影响节理面起伏度对剪切强度的贡献,尺寸越大,其剪切强度也越大;法向应力较小时,初始剪切刚度较大,应力-应变曲线存在峰值;法向应力较大时,初始剪切刚度较小,应力-应变曲线无峰值,剪切强度随应变增大而增大,最终趋于稳定.
[Abstract]:The shear strength and deformation of loess joints have an important effect on the engineering stability, but the research on this is not enough at present. Therefore, the natural vertical joints of loess are first collected in this study. Then the shear strength and deformation properties of natural joints of loess are studied by means of indoor large direct shear test method, and the results are compared with those of small scale direct shear tests. The effect of size effect on the shear strength of loess joints is obtained. The results show that the maximum internal friction angle of loess joint shear is 47.37 掳and the small direct shear test value is 35.17 掳. The size effect exists in the direct shear test of loess joints. The size of the specimen mainly affects the contribution of the undulation of the joint surface to the shear strength. The larger the size, the greater the shear strength. When the normal stress is small, the initial shear stiffness is larger, and the stress-strain curve has a peak value. When the normal stress is larger, the initial shear stiffness is smaller, the stress-strain curve has no peak value, and the shear strength increases with the increase of strain, and finally tends to be stable.
【作者单位】：西安建筑科技大学土木工程学院;西安长庆科技工程有限责任公司;
【基金】：国家自然科学基金资助项目(51408464) 陕西省教育厅基金专项资助(14JK1413) 西安建筑科技大学人才科技基金项目(RC1365)
【分类号】：TU444
【正文快照】： 黄土节理在黄土地区普遍存在,其抗剪强度及变形规律是影响工程稳定性的重要因素.因此,对黄土节理工程力学特性进行研究有重要意义.目前,已有一些学者研究了黄土节理的外貌特征、地域分布以及形成机制等特性[1-3],而对于黄土节理力学特性的研究则相对较少.王铁行、罗扬[4]等采

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