不同加载速率下粉煤灰掺量对煤矸石充填体变形破坏的影响  

Influence of Fly Ash Dosage on the Deformational and Fracture of Coal Gangue Backfills Subjected to Varied Loading Rates

作　　者：朱磊 刘成勇 古文哲 刘治成 赵萌烨 何志伟 邱华富[2] 梁超 何国庆 ZHU Lei;LIU Chengyong;GU Wenzhe;LIU Zhicheng;ZHAO Mengye;HE Zhiwei;QIU Huafu;LIANG Chao;HE Guoqing(China Coal Energy Research Institute Co.,Xi′an 710000,China;College of Energy Engineering,Xi′an University of Science and Technology,Xi′an 710054,China)

机构地区：[1]中煤能源研究院有限责任公司,陕西西安710000 [2]西安科技大学能源学院,陕西西安710054

出　　处：《金属矿山》2025年第3期292-298,共7页Metal Mine

基　　金：中煤集团重大科技项目(编号:ZMYXM·JT-22-02)。

摘　　要：为了解不同加载速率下矿井煤矸石充填体的安全可靠性,开展了不同灰砂比、不同粉煤灰掺量下,充填料浆的流动性、充填体试样不同加载速率下的单轴抗压强度及压缩过程中的变形破坏特征研究。结果表明:①粉煤灰(FA)能够有效改善料浆的流动性能,在试验掺量下,充填料浆的坍落度、扩展度、初凝时间、终凝时间、泌水率的最大变动量为+28.56%、+39.08%、+58.50%、+63.08%、-52.73%。②在FA掺量30%、灰砂比1∶4、加载速率为1.0 mm/min情况下,充填体试样的单轴抗压强度最大。③随着加载速率和FA掺量的增加,充填体试样应力-应变曲线在间隙压密阶段呈现加速完成趋势、线弹变形阶段斜率增大、裂隙破坏阶段峰值强度增强等现象。④FA掺量从10%增加到30%,充填体试样的主要破坏形式由单一拉伸、剪切等向复杂的拉剪破坏转化,且破坏性有所增强;加载速率从0.5 mm/min增至2.0 mm/min,充填体试样受破坏程度也明显增强。In order to evaluate the safety and reliability of coal gangue backfill in mines under different loading rates,this study investigated the fluidity of backfill slurry with varying binder-tailings ratios and fly ash(FA)contents,as well as the uniaxial compressive strength and deformation/failure characteristics of backfill specimens under different loading rates.The results demonstrate that:FA significantly enhances slurry fluidity.Within the tested dosage range,the maximum variations in slump,spread diameter,initial setting time,final setting time,and bleeding rate reached +28.56%,+39.08%,+58.50%,+63.08%,and -52.73%,respectively;The maximum uniaxial compressive strength of backfill specimens was achieved under optimal conditions∶FA content of 30%,binder-tailings ratio of 1∶4,and loading rate of 1.0 mm/min;With increasing loading rates and FA contents,the stress-strain curves exhibited the following trends:accelerated completion of the pore compaction stage;Increased slope during the linear elastic deformation stage;Enhanced peak strength in the crack propagation and failure stage;As FA content increased from 10% to 30%,the dominant failure mode transitioned from simple tension/shear to complex tension-shear composite failure,with intensified damage severity.Concurrently,increasing loading rates from 0.5 mm/min to 2.0 mm/min markedly exacerbated specimen damage.

关 键 词：胶结充填体 料浆流动性 加载速率 变形破坏 

分 类 号：TD823[矿业工程—煤矿开采]