基于Hoek-Brown准则的砂岩卸荷强度损伤试验研究  

Experimental Study of Unloading Strength Damage of Sandstone Based on Hoek-Brown Failure Criterion

作　　者：龚家伟[1] 王乐华[1] 许晓亮[2] 杨超[1] 徐义根[1] 吴文惠[3] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [3]三峡大学外国语学院,湖北宜昌443002

出　　处：《水电能源科学》2016年第4期100-102,114,共4页Water Resources and Power

基　　金：国家自然科学基金项目(51279091);三峡大学土木与建筑学院2014年硕士创新基金(CX2014011)

摘　　要：为研究卸荷效应对岩体强度变化的影响,以三峡地区砂岩为样本,通过三轴加载和卸荷试验,运用Hoek-Brown岩体破坏准则,探讨砂岩在不同卸荷速率条件下的强度损伤规律,并提出采用卸荷强度损伤因子来表征卸荷造成的强度变化。结果表明,卸荷条件下砂岩强度损伤明显,且与围压密切相关;随着围压的增大,卸荷效应造成的强度损伤量增大,最终趋于稳定。最后,基于工程设计最不利原则,修正了Hoek-Brown卸荷强度准则公式,为工程应用提供了建议和参考。In order to investigate the impact of unloading behavior on the strength of rock mass,this paper conducted loading and unloading triaxial tests on sandstone coming from the Three Gorges area.Hoek-Brown criterion was used to analyze the strength damage of the sandstone in unloading conditions.A factor was proposed to evaluate the damage of strength caused by unloading behavior.The test results show that the strength of sandstone reduced apparently under unloading condition,and the reduction closely related to the level of confining pressure.With the confining pressure increasing,the unloading-induced strength damage increased gradually and tended to be stable.Finally,a revised Hoek-Brown criterion was put forward to incorporate the influence of unloading effects based on the rule of the worst condition,which provides reference for engineering application.

关 键 词：HOEK-BROWN准则 卸荷 强度损伤 围压 

分 类 号：TU45[建筑科学—岩土工程]