多源煤基固废充填体强度演化规律及声发射特征  

Strength evolution law and acoustic-emission characteristics of multi-source coal-based filling body of solid wastes

作　　者：华心祝[1,2] 常贯峰 刘啸[1,2,3] 杨科 陈登红[1,2] 李琛[1,2] 王恩乾 HUA Xinzhu;CHANG Guanfeng;LIU Xiao;YANG Ke;CHEN Denghong;LI Chen;WANG Enqian(State Key Laboratory of Deep Coal Mines Excavation Response and Disaster Prevention and Control,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;State Key Laboratory of Coal Safety,Shenyang Branch of China Coal Research Institute,Fushun,Liaoning 113000,China)

机构地区：[1]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001 [2]安徽理工大学矿业工程学院,安徽淮南232001 [3]中煤科工集团沈阳研究院有限公司煤矿安全技术国家重点实验室,辽宁抚顺113000

出　　处：《岩石力学与工程学报》2022年第8期1536-1551,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划资助项目(2019YFC1904304);国家自然科学基金资助项目(51774010)。

摘　　要：为探究多源煤基固废充填体力学特性,制备29组尺寸为70.7 mm的立方体试件,采用单轴压缩实验系统得到不同龄期充填体试件抗压强度,利用XRD,SEM微观观测技术分析原材料的微观形貌及物质成分组成,并采集不同龄期试件断面微观形态结构,揭示充填体强度演化规律;基于响应面法研究各组分对不同龄期(3,14,28 d)充填体强度的影响,应用声发射测试系统监测试件破坏过程中声发射特征。研究结果表明:各因素对试件强度影响的显著性大小为:粉煤灰>矸石>脱硫石膏>气化渣与炉底渣的1∶1混合物;响应面法得到粉煤灰及矸石对充填体试件的抗压强度影响较大;新生成的棒状结晶物及蜂窝棉絮状胶凝物质随龄期的增长逐渐增多,从而使充填体强度增高;试件3 d强度最小,3~14 d强度增加幅度最大,14~28 d强度增加幅度次之;塑性变形阶段,有少量能量释放,试件表面出现细微裂纹,并逐渐演变成贯通裂隙;屈服破坏阶段,声发射振铃计数陡然增大,试件内部集聚的能量突然释放,试件表面出现明显贯通式裂隙,并逐渐裂开、崩落;峰后阶段,试件依然具有一定的强度,声发射事件依然存在,并伴随能量释放,研究成果可为工程现场充填材料配比优化提供依据。Twenty-nine groups of cube specimens with a size of 70.7 mm were prepared to explore the mechanical properties of the multi-source coal-based filling body of solid wastes.The compressive strength of the filling specimens at different ages was obtained by using an uniaxial compression test system.The micromorphology and material composition of the raw materials were analyzed by XRD and SEM,and the cross-section micromorphology of the specimens at different ages was collected,to reveal the strength evolution law of the filling body.The effects of each component on the filling body strength at different ages(3,14,and 28 d)were studied based on the response surface method,and the acoustic-emission characteristics of the specimens in the whole failure process were monitored adopting an acoustic-emission test system.The results show that the influence of fly ash on the strength of the specimen is most significant,followed by gangue,desulfurization gypsum and 1∶1 mixture of gasification slag and bottom slag.Analysis by the response surface method presents that fly ash and gangue significantly affect the compressive strength of the filled specimens.The newly formed rod-shaped crystals and honeycomb cotton-flock cementitious materials gradually increase with age,which increases the strength of the filling body.The strength of the specimens at 3 d age is the maximum,and the increment of the strength of the specimens increases is largest at 3-14 d age followed by that at 14-28 d age.At the plastic-deformation stage,a few ring counts and small-amplitude energy release exist,and fine cracks appear on the specimen surface,which gradually evolve into through cracks.At the yield failure stage,the acoustic emission ring count increases sharply,and the energy accumulated in the specimen is released suddenly through the cracks on the specimen surface,resulted in the specimens to gradually crack and collapse.At the post-peak stage,the specimens still have a certain strength,and the acoustic emission event is still active,accompani

关 键 词：采矿工程 煤基固废 充填开采 充填体 力学特性 声发射 响应面法 

分 类 号：TD32[矿业工程—矿井建设]