收稿日期: 2016-09-05
修回日期: 2016-12-20
网络出版日期: 2018-05-25
基金资助
国家自然科学基金项目“深埋硬岩劈裂破坏的强度准则和动静载荷组合作用机理研究”(编号41472269)资助
Research on Evaluation Index of Red Sandstone Instability Under Different Stress
Received date: 2016-09-05
Revised date: 2016-12-20
Online published: 2018-05-25
为了研究不同受力维度下岩石峰值应力、峰值应变与失稳的关系,分别对红砂岩进行一维、二维、三维受力条件下的单轴抗压试验、变角板剪切试验和直接剪切试验以及三轴压缩试验。试验结果显示:单轴压缩试验中,峰值应力和峰值应变变异系数分别为6.61%和9.36%;变角板剪切试验中,峰值应力和峰值应变平均变异系数分别为5.69%和19.81%;直接剪切试验中,峰值应力和峰值应变平均变异系数分别为4.32%和14.74%;三轴压缩试验中,峰值应力和峰值应变平均变异系数分别为6.03%和7.44%。上述研究表明:当红砂岩处于一维和三维受力状态时,峰值应力和峰值应变均可以作为评判红砂岩是否失稳的指标,但峰值应力比峰值应变作为评判指标的可靠性更高;当红砂岩处于二维受力状态时,只有峰值应力能作为评判红砂岩是否失稳的指标。上述研究规律不仅对评判室内试验中岩石是否失稳具有重要意义,而且对评判岩土工程中岩石是否处于安全状态提供理论依据。
林格 , 宫凤强 . 不同受力维度下红砂岩失稳评判指标研究[J]. 黄金科学技术, 2018 , 26(2) : 195 -202 . DOI: 10.11872/j.issn.1005-2518.2018.02.195
In order to study the relationship between peak stress,peak strain and the stability state of red sandstone under different stress dimensions,uniaxial compression test under one-dimensional stress,variable angle plate shear test and direct shear test under two dimensional stress,three axis compression test under three dimensional stress were carried out.The results show that:the coefficient variation of peak stress and peak strain are 6.61% and 9.36% respectively in uniaxial compression test.The average coefficient variation of peak stress and peak strain are 5.69% and 19.81% respectively in variable angle plate shear test.In the direct shear test,the average coefficient variation of peak stress and peak strain are 4.32% and 14.74% respectively.The average coefficient variation of peak stress and peak strain are 6.03% and 7.44% respectively in the three axial compression tests.Research shows:when sandstone is under the one-dimensional or three-dimensional stress state,the peak stress and peak strain can be used as indexes to judge whether the red sandstone is unstable, but the peak stress is more reliable than the peak strain as the evaluation index.When the sandstone is under the two-dimensional stress state,only the peak stress can be used as an index to judge whether the red sandstone is unstable or not.The above research rule is not only important to judge whether the rock is unstable in laboratory test,but also provides a theoretical basis for judging whether rockmass is in safety state in geotechnical engineering.
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