岩石非均匀性和围压对Kaiser效应的影响  

Numerical simulation of impact on Kaiser effect by rock heterogeneity and confining pressure

作　　者：王立君[1,2] 刘建坡[1] 杨宇江[1] 李元辉[1] 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004 [2]山东黄金集团有限公司,山东济南250014

出　　处：《辽宁工程技术大学学报（自然科学版）》2010年第2期240-243,共4页Journal of Liaoning Technical University (Natural Science)

基　　金：国家高技术研究发展计划基金资助项目(2007AA06Z107);教育部新世纪优秀人才支持计划基金资助项目(NCET-07-0163);国家科技支撑计划基金资助项目(2008BAB34B02);国家自然科学基金资助项目(50974031);中央高校基本科研业务费基金资助项目(N090401006)

摘　　要：为了解采用Kaiser效应测原岩应力过程中的影响因素,应用岩石破裂过程分析软件(RFPA2D)对岩样进行数值模拟分析。结果表明:利用Kaiser效应测得的原岩应力值比真实值要小;岩石先前所受围压越大,岩石的均匀性越差,利用该方法测得的Felicity比值越小,Kaiser效应点应力值与真实值相差越大;对于均匀性极差的试样,Felicity比值曲线在首次加载施加围压后出现明显的拐点;随着岩石均质度的提高,先前所受围压对于Kaiser效应的影响逐渐降低。Kaiser效应的本质是对岩石内部损伤的记忆而不是对先前所受最大应力的记忆,要想得到准确的原岩应力,必须根据岩石的损伤本构关系对单轴加载得到的Kaiser效应点应力值进行修正。To understand the influence factors in the process of estimating in-situ stress using Kaiser effect,an numerical simulation was conducted using Rock Failure Process Analysis （RFPA2D） software.The results show that the traditional method for estimating in-situ stress using Kaiser effect is not appropriate as the stress value obtained is usually lower than real value.Furthermore,if the specimen with higher confining compression and lower heterogeneity,it would result in greater difference between the Kaiser effect stress obtained from uniaxial loading in laboratory and the real value of in-situ stress.For the specimens with very low heterogeneity,there is an inflexion point on Felicity ratio curves after the uniaxial loading and confining pressure is applied in the first loading cycle.The effect of confining stress level in previous loading cycle tends to be less with the increase of rock heterogeneity.The mechanism of Kaiser effect is the memory of damage level in rock.Therefore,to accurately estimate the in-situ stress,the adjustment on the Kaiser effect stress value obtained from uniaxial loading must be made based on the damage constitutive relation.

关 键 词：KAISER效应 均质度 围压 声发射 数值模拟 

分 类 号：TD315[矿业工程—矿井建设]