不同高比灰岩-煤组合体变形破坏特征实验研究  

Experimental study on deformation failure characteristics of limestone−coal composite with different rock-coal height ratios

作　　者：陈绍杰[1,2] 李法鑫 尹大伟[1,2] 张继成[1,2] CHEN Shaojie;LI Faxin;YIN Dawei;ZHANG Jicheng(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学能源与矿业工程学院,山东青岛266590 [2]山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地,山东青岛266590

出　　处：《中南大学学报（自然科学版）》2023年第6期2459-2472,共14页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51904167,52274128,52074169)。

摘　　要：为探究不同岩煤(高度)比的灰岩-煤组合体试样变形破坏特征,首先,对5组组合体试样进行了单轴压缩试验;其次,基于声发射系统和XTDIC三维全场应变测量系统,采集了加载全程试样声发射信号及其表面应变信息;最后,从变形场演化、回弹变形、能量耗散和声发射特征等方面,定量揭示了组合体试样的变形破坏特征。研究结果表明:随着岩煤高比增大,组合体试样单轴压缩强度和弹性模量均呈增大趋势,其破坏均发生在煤样内,由张拉破坏向拉-剪混合破坏转变,塑性破坏增强;变形局部化带首先出现在煤样原生裂纹区域,且随着裂纹的起裂、扩展而发生交汇,进而诱发煤样破坏;同时,煤样破坏导致灰岩回弹变形,随着岩煤高比增大,灰岩回弹变形量由0.042 mm递减至0.008 mm,回弹变形率由0.210%递减至0.010%,回弹变形量和回弹变形率整体呈递减趋势。随着岩煤高比增大,组合体试样峰前弹性能密度占比由98.56%递增至99.86%,外界能量转化为弹性能的能力增大,峰后弹性能转化为峰后释放能和剩余弹性能的能力增大,破坏后宏观裂纹增多且动力显现程度增大。组合体试样声发射能量率信号具有明显的时效特征,分为波动、静寂、活跃和骤增4个阶段,当组合体试样发生整体破坏时,声发射能量率信号达到最大值。The aim of the study is to explore the deformation failure characteristics of limestone-coal composite samples with different rock-coal(height)ratios.Firstly,uniaxial compression tests on 5 groups of composite samples were conducted.Secondly,based on an acoustic emission monitoring system and XTDIC three-dimensional full-field strain measurement system,the acoustic emission signal and surface strain information of the whole loading process sample were collected.Finally,the deformation failure characteristics of composite samples were quantitatively revealed from the aspects of deformation field evolution,rebound deformation,energy dissipation,and acoustic emission characteristics.The results show that with the increase in rock-coal height ratios,the uniaxial compressive strength and elastic modulus of composite samples increase.The failure occurs in the coal sample,changes from tension failure to tension shear mixed failure,and the plastic failure is strengthened.The deformation localization zone first appears in the primary crack of zone coal samples.With the initiation and propagation of cracks,it intersects and then induces the failure of coal samples.At the same time,the destruction of coal samples leads to the rebound deformation of limestone.With the increase of rock-coal height ratios,the rebound deformation amount of limestone decreases from 0.042 mm to 0.008 mm,and the rebound deformation rate decreases from 0.210%to 0.010%.The rebound deformation amount and the rebound deformation rate show a decreasing trend as a whole.With the increase of rock-coal height ratios,the proportion of elastic property density before the peak of composite samples increases from 98.56%to 99.86%,the ability of the composite sample to convert external energy into elastic energy increases before the peak,and the ability to convert elastic energy into post-peak release energy and residual elastic energy increases after the peak.After the failure of the composite sample,the macro cracks increase,and the degree of dynamic appearan

关 键 词：岩煤高度比 灰岩-煤组合体 强度特征 变形破坏 能量演化 

分 类 号：TD315[矿业工程—矿井建设]