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
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.
LIN Ge , GONG Fengqiang . Research on Evaluation Index of Red Sandstone Instability Under Different Stress[J]. Gold Science and Technology, 2018 , 26(2) : 195 -202 . DOI: 10.11872/j.issn.1005-2518.2018.02.195
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