摘要
本文根据大量初次来压步距的统计和老顶“板”模型破断规律的研究,论述了老顶初次来压步距a_i的构成。它由反映其自身稳定性的步距准数l_m与反映工作面长度和开采边界影响的“边—长”系数W_i之积构成,即a_i=l_m·w_i。得出了工作面长度对老顶来压步距及其极限悬露面积的影响均呈w形曲线关系的结论。开采边界不同,其w形曲线也略有差异。据此,提出了常见的四种开采边界条件下来压步距的计算方法,以及利用实测步距推广到邻近工作面中去的换算方法。同时,对顶板分类提出应以步距准数l_m为指标,并用作w形曲线图法进行分类。
Based on the statistics of first weighting span in some collieries and the study on the fracture behaviour of the 'plate' model of main roof, it is obtained that the first weighting span of main roof can be expressed by ai = lm - wt , where lm is span criterion, which represents the beam stability of the main roof; and the boundary-length coefficient wi , represents the effect of face length and boundary conditions on first weighting span.
The relation of face length to the first weighting span and the limit overhanging area can be ploted as a w-shaped curve. Taking lm as criterion, and ploting w-shaped curves a new method of roof classification can also be obtained.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
1989年第2期9-18,共10页
Journal of China University of Mining & Technology
关键词
老顶
初次来压
步距准数
开采边界
main roof, first weighting, span criterion, extracting boundary
