| 孔隙水压力条件下含缺陷岩样破坏过程及声发射模拟 |
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| 引用本文： | 王学滨,代树红,潘一山.孔隙水压力条件下含缺陷岩样破坏过程及声发射模拟[J].中国地质灾害与防治学报,2009,20(2):52-59. |
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| 作者姓名： | 王学滨 代树红 潘一山 |
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| 作者单位： | 辽宁工程技术大学力学与工程科学系,辽宁,阜新,123000 |
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| 基金项目： | 国家自然科学基金重大项目及青年基金项目 |
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| 摘 要： | 在平面应变压缩条件下,采用FLAC模拟了围压存在时孔隙压力对具有初始随机材料缺陷的岩石的破坏过程、前兆及声发射的影响。密实的岩石服从莫尔库仑剪破坏与拉破坏复合的破坏准则,破坏之后呈现应变软化-理想塑性行为。缺陷在破坏之后经历理想塑性行为。在孔隙压力存在时,缺陷在施加轴向加载速度之前就发生了破坏。当施加轴向速度后,声发射累积数先一度保持恒定,然后由于缺陷的长大声发射累积数发生了少量的突增。经历了一段短暂的平静之后,由于短剪切带聚合成长剪切带声发射累积数发生了大量的突增,穿越应力峰值。之后,仅有零星声发射活动,试样处于平静的残余变形阶段。随着孔隙压力的增加,应力峰值达到时的声发射累积数提高,应力峰值附近的声发射活动变得强烈,残余变形阶段达到时的声发射累积数提高。出现在软化阶段的最大失衡力的峰值随着孔隙压力的增加而降低。
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| 关 键 词： | 材料缺陷 孔隙压力 剪切带 声发射 最大失衡力 密实岩石 |
Numerical simulation of failure processes and acoustic emissions of rock specimen with imperfections under different pore pressures |
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| WANG Xue-bin,DAI Shu-hong,PAN Yi-shan.Numerical simulation of failure processes and acoustic emissions of rock specimen with imperfections under different pore pressures[J].The Chinese Journal of Geological Hazard and Control,2009,20(2):52-59. |
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| Authors: | WANG Xue-bin DAI Shu-hong PAN Yi-shan |
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| Institution: | (Department of Mechanics and Engineering Sciences, Liaoning Technical University, Fuxin 123000, China) |
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| Abstract: | For rock specimen,with initially random material imperfections,under different confining pressures and plane strain compression,the effects of pore pressure on the failure processes and acoustic emissions are numerically modeled using FLAC.For the intact rock element exhibiting linear strain-softening behavior beyond the occurrence of failure,and then ideal plastic behavior,the failure criterion is a composite Mohr-Coulomb criterion with tension cut-off.The imperfection undergoes ideal plastic behavior beyond the occurrence of failure.Imperfections fail under pore pressure before the axial loading velocity is exerted.After the axial loading velocity is exerted,the accumulated number of acoustic emissions remains a constant.Then,owing to the axial extension of imperfections the accumulated number of acoustic emissions slightly increases.After a short silence,the accumulated number of acoustic emissions rapidly increases since shorter shear bands coalesce to form longer shear bands,intersecting the rock specimen.This process occurs prior to the peak stress and beyond it.Afterwards,only a few acoustic emissions appear,and the rock specimen is in residual deformational stage.As pore pressure growing,the accumulated number of acoustic emissions increases,corresponding to the peak stress;the acoustic emissions in the vicinity of the peak stress become intensive;and the accumulated number of acoustic emissions increases when residual stage is reached.The peak of the maximum unbalanced force appears in the strain-softening stage and it decreases with an increase of pore pressure. |
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| Keywords: | material imperfections pore pressure shear band acoustic emissions maximum unbalanced force intact rock |
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