摘要
针对煤矿山保护煤柱留设问题,开展了不同宽高比的煤柱单轴压缩试验,引入损伤变量及损伤统计本构模型,探讨全应力-应变过程中损伤变量与应变之间的关系。采用定量分析方法,得出煤柱尺寸与损伤变量之间的演化规律,即损伤变量受煤柱宽高影响显著,随着宽度增大,高度减小,损伤变量值减小,峰值应力增大;在煤柱受力至破坏状态的过程中,当宽高比为2时,煤柱损伤变量所受影响较小。综合考虑破坏峰值和损伤变量之间的关系,煤柱留设宽高比等于2为留设煤柱的最佳比例,其对煤矿开采的保护作用较好。损伤变量随应变的增加呈初始损伤阶段、损伤线性增加段和损伤平稳段,但总体上损伤变量与应变之间呈非线性正指数关系。
The present paper is inclined to search for the regularity of the coal pillar residua setting-up based on the study of the damage variables. For this purpose, we have conducted the experiments to trace the relationship between the damage variable and the stress- strain in the course of the total failure process by using the damage variables which can be detected based on the constitutive model for the rock damage, but the damage variables have to be made well- suited for explaining the damage degree of the materials. In addition, the method for measuring the reasonable size of the coal pillar residua can be obtained by comparing the different damage variables of vari- ous coal pillars, whose evolution regularities can be summarized by using the method of quantitative analysis of the relation between the pillar size and the damage variable by the following factors： it is re- markable for the influence of width/height change on the damage variable, that is to say, with the increase of the width and decrease of the height may lead to the damage variable decrease and peak value increase while the width/height ratio is 2 by considering the peak val- ue and the damage variable for protecting the coal seam. Thus, the damage variable with the strain can be described by the positive expo- nential function though the regularity between the damage variable and the strain can be deduced from the zero damage stage with the linear damage stage increase and stable damage stage prolonging. However, the stages may have different imp^tications, that is to say, the zero damage stage is a process of consolidating the coal matrix, whereas the linear increasing damage stage is referred to as the micro-fracture emerging and fast extension. Moreover, it is necessary to point out that the stable damage stands for a state of complete breach of the coal pillar in the experiment. Thus, the relationship of the multiple linear regressions with the damage variable, peak value, width/ height ratio and height can be used to denote a reasonable pillar size.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第5期179-182,共4页
Journal of Safety and Environment
基金
国家重点基础研究发展计划(973)资助项目(2011CB201206)
国家自然科学基金项目(50904033)
辽宁省自然科学基金资助项目(20102090)
关键词
采矿工程
宽高比
损伤变量
原煤
煤柱留设
mining engineering
width/height ratio
damage vari- able
raw coal
coal pillar residua
