1. School of Environment and Resource,Southwest University of Science and Technology,Mianyang　 621010,China; 2. School of Resource and Environmental Engineering,Wuhan University of Science and Technology,Wuhan　 430081,China

改进的Hoek-Brown准则可以降低高围压下HB准则过高预测岩石三轴强度的偏差值。然而,该准则在实际应用中仍然存在局限:通过应用大量岩石三轴试验数据验证了该准则中岩石临界状态围压等于单轴抗压强度这个观点并不具有普适性,并得出该准则在围压高于岩石单轴抗压强度时对其预测的三轴强度与试验强度存在较大的偏差,而且该偏差随着围压的增大而增加。为克服改进的HB准则这个应用局限,通过应用岩石临界状态及岩石临界状态系数对该准则进行修正,提出了I-HB准则。应用大量岩石三轴试验数据对I-HB准则的适用性进行验证,结果显示该准则有效地解决了改进的HB准则的应用局限,并且该准则预测的岩石三轴强度与岩石试验强度更一致,证明I-HB准则优越于改进的HB准则。另外,通过与目前岩石力学界认为较好的指数型准则的比较,验证了I-HB准则对岩石三轴强度的预测具有更高的精度。

The modified Hoek-Brown criterion can reduce the deviations of the over-predicted rock triaxial strength values at high confining pressures by HB criterion. However,this criterion still has some application limitations. The point,in the modified HB criterion,that rock critical confining pressure equals to uniaxial compressive strength is not of universality. Rock triaxial strength predicted by the modified HB criterion significantly deviates from the test strength since confining pressure reaches the value of uniaxial compressive strength,and this deviation increases with the in- crease of confining pressure. In order to overcome the aforementioned limitation,the modified HB criterion is improved by employing rock critical state and rock critical state coefficient,and a new criterion called I-HB criterion is pro- posed. The applicability of the I-HB criterion has been verified by using an extensive database of rock triaxial strength tests from literatures. The result shows that this criterion successfully overcomes the limitation of the modified HB crite- rion,and the I-HB criterion predicted rock triaxial strength values are more consistent with the test values. Thus,the I- HB criterion is superior to the modified HB criterion. Furthermore,by comparing with exponential criterion,which is regarded as an outstanding criterion in rock engineering,the I-HB criterion has been verified having a higher accuracy in predicting rock triaxial strength.

国家自然科学基金资助项目(51074115)；四川省教育厅科研资助项目(16CZ0013)；西南科技大学博士研究基金资助项目(15zx7134)；

Li Bin,Wang Daguo,Liu Yanzhang,et al. Improvement of modified Hoek-Brown criterion under conventional triaxial compression condi- tions[J]. Journal of China Coal Society,2017,42(5):1173-1181.