花岗岩脆延破坏过程声发射与损伤特性模拟研究  

Simulation of Acoustic Emission and Damage Properties of Granite in Brittle and Ductile Failure Processes

作　　者：王云飞[1] 杨文选 焦华喆[1] 王立平[1] 赵洪波[1] 

机构地区：[1]河南理工大学土木工程学院,河南焦作454000 [2]河南工业和信息化职业学院土木工程系,河南焦作454000

出　　处：《长江科学院院报》2016年第7期76-80,86,共6页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(51104057);河南省教育厅重点资助项目(13A440323);河南省高校科技创新团队支持计划资助项目(15IRTSTHN029);河南理工大学博士基金项目(B2012-075);煤炭工业协会科学技术研究计划项目(MTKJ2013-338)

摘　　要：为了研究花岗岩脆性和延性破坏过程的声发射特性和损伤演化机制,通过花岗岩单轴试验和颗粒流程序进行了不同围压试验,获得了花岗岩破坏过程中的声发射曲线并再现了内部损伤演化过程。试验结果表明:花岗岩脆延破坏分界围压约为100 MPa;花岗岩脆性破坏时最大声发射强度的滞后效应受围压影响显著,围压越大滞后效应越不明显,延性破坏时最大声发射强度与峰值应力同时出现,滞后效应消失。花岗岩脆性破坏声发射曲线为单峰型,延性破坏声发射为平缓曲线。脆性破坏花岗岩内部严重损伤区少且分布集中,损伤区裂隙发展方向单一,延性破坏内部损伤区多且遍布整个试样,损伤区裂隙主要沿2个相互正交方向发展;花岗岩破裂角随围压增大逐渐减小,由低围压下的破裂面转变为高围压下的破碎带,低围压脆性破坏花岗岩被破裂面切割成数块,高围压下延性破坏呈粉碎性状态。In order to explore the acoustic emission characteristics and damage evolution mechanism of granite in brittle and ductile failure processes,we carry out uniaxial experiment on granite,and simulated experiment under different confining pressures through PFC（ particle flow code）. On the basis of test,we obtain the acoustic emission curve in failure process and reproduce the evolution process of internal damage. Test results are as follows： 1） critical confining pressure from brittle failure to ductile failure is 100MPa; 2） lag effect of maximum acoustic emission intensity is significantly affected by confining pressure in brittle failure,and the greater confining pressure is,the less obvious lag effect is; 3） in ductile failure,maximum acoustic emission intensity and peak stress appear in the same time without lag effect; 4） acoustic emission curve has single peak in brittle failure,while gentle curve form in ductile failure; 5） there are few internal serious damage zones in brittle failure with concentrated distribution,and crack extension tends to be in the same direction; 6） internal serious damage zones which distribute throughout the specimen in ductile failure are more than those in brittle failure,and crack extends mainly along two mutually orthogonal directions; 7） rupture angle gradually reduces as confining pressure increases,and rupture surface transforms into crushing zone with the increasing of confining pressure; 8） in brittle failure with low confining pressure,rock is cut into a few blocks,while in ductile failure with high confining pressure,the rock destruction is comminuted.

关 键 词：花岗岩 脆性破坏 延性破坏 声发射 损伤机理 

分 类 号：TU45[建筑科学—岩土工程]