三轴剪切作用下体积变化对岩石其他力学性质影响  

INFLUENCE OF VOLUME CHANGE ON OTHER MECHANICAL BEHAVIORS OF ROCKS SUBJECT TO TRIAXIAL SHEARING

作　　者：王者超[1] 李术才[1] 乔丽苹[2] 杨文东[3] 

机构地区：[1]山东大学岩土与结构工程中心,济南250061 [2]山东大学工程力学系,济南250061 [3]中国石油大学(华东)储运与建筑工程学院,青岛266555

出　　处：《固体力学学报》2013年第5期527-535,共9页Chinese Journal of Solid Mechanics

基　　金：国家自然科学青年基金项目(51309145和41202205);教育部博士点基金(20120131120038);山东大学自主创新基金(2012TS058)资助

摘　　要：岩石体积变化影响其强度和变形等特性.开展了岩石的常规三轴压缩、疲劳和蠕变试验,分析剪缩和剪胀对岩石完整性、疲劳特性和蠕变特性的影响.研究发现,(1)岩石剪胀随围压增加而减小,剪胀线可用来描述岩石完整性变化情况;(2)循环荷载试验中,剪缩区域内岩石变形模量随循环次数增加而变大,而剪胀区域内变形模量随循环次数增加而变小;(3)蠕变试验中,剪缩区域内岩石轴向应变随时间增加而减小;而剪胀区域内轴向应变随时间增加而增加,蠕变速率随时间增加而减小;(4)三轴剪切应力作用下,岩石表现出三种不同性质:剪缩、硬化剪胀和软化剪胀,不同性质区域内岩石变形宏细观机制不同.岩石在剪缩范围内将不会发生疲劳和蠕变破坏,而在剪胀范围内则会发生疲劳和蠕变破坏.Volume change influences the strength and deformation characteristics of rock.A series of conventional triaxial compression,fatigue and creep tests was performed to investigate the influences of shear contraction and dilation on the integrity,fatigue and creep behaviors of rocks.It is found that （1） the dilation of rock decreases with the increasing confining pressure and the dilation line can be employed to describe the integrity of rocks; （2） in cyclic loading tests,the deformation modulus of rock decreases with cycle number in the domain of shear contraction,while it increases with cycle number in the domain of shear dilation; （3） in creep tests,the axial strain decreases with time in the domain of shear contraction,while it increases with time in the domain of shear dilation; （4） when subjected to triaxial shearing,rocks exhibit three different behaviors：shear contraction,dilation with strain hardening and dilation with strain softening,for which different macro and micro mechanisms prevail.Fatigue or creep failure can occur in the shear dilation domain,while it can not occur in the shear contractive domain.

关 键 词：岩石力学 三轴剪切 体积变化 完整性 疲劳 蠕变 剪缩 剪胀 破坏 

分 类 号：TU452[建筑科学—岩土工程]