矸石充填材料承载压缩变形时效性试验研究

Experimental study on time-dependent compressive deformation of gangue backfilling materials

掌握矸石充填材料承载压缩变形时效性是矸石充填开采顶板变形、岩层移动与地表沉陷预计的重要基础。基于矸石充填材料在采空区的受力状态,分析了矸石充填材料承载压缩变形特征,借助自制的散体充填材料双向加载试验系统,采用分级加载方式测试了矸石充填材料承载压缩特性,得到了矸石充填材料在承载过程中的瞬时与蠕变压缩变形规律。研究结果表明:1)矸石充填材料本身的强度越高,其瞬时与蠕变压缩应变越小;2)随着轴向应力增加,矸石充填材料瞬时压缩应变占总应变的比例逐渐减小,而蠕变压缩应变占总应变的比例逐渐增大;3)随着蠕变时间增加,矸石充填材料瞬时压缩应变占总应变的比例逐渐减小,而蠕变压缩应变占总应变的比例逐渐增大。

Mastering the time-dependent compressive deformation of gangue backfilling materials could provide significant basis for prediction of roof deformation, strata movement and surface subsidence during gangue backfilling mining. Based on forced state of gangue backfilling materials in the goaf, compressive deformation characteristics of gangue backfilling materials were analyzed. Through adopting self-made bidirectional loading test system for bulk backfilling materials, the compressive deformation characteristics of gangue backfilling materials were tested based on multi-stage loading method to gain instantaneous and creep compression deformation law of gangue backfilling materials in loading process. Research results indicate that: 1) the higher the strength of gangue backfilling materials is, the smaller the instantaneous and creep compression strain are. 2) As axial stress increases, the ratio of instantaneous compressive strain to total strain of gangue backfilling materials gradually decreases, while that of creep compressive strain to total strain gradually increases. 3) When creep time increases, the ratio of instantaneous compressive strain to total strain of gangue backfilling materials gradually decreases, while that of creep compression strain to total strain gradually increases.