摘要
点柱式上向水平分层充填采矿法通过留设点柱和分层充填实现超大采场结构开采。根据该法充填回采特点,研究了充填体接顶前点柱-充填体协同支护原理,分析了充填体对点柱的作用机理,推导出分层充填时点柱垂直应力理论计算公式,据此优化点柱形状,提出下宽上窄圆台形新型点柱。以李官集铁矿为例,采用数值模拟方法,对不同充填高度下方形、矩形、圆形及圆台形4种形状的点柱的应力分布情况及支护效果进行分析。结果表明:下宽上窄圆台形点柱支护顺应点柱垂直应力及剪应力的分布规律,在底部垂直应力及剪应力最大处承载面积达到最大,随着充填高度的增加,相应地减少承载面积及与充填体的接触面积,有效降低充填体"下拉"效应,保证支护效果的同时,降低矿石损失率。
The super-large stope structure mining can be realized through the permanent pillars and slice filling in the upward-to-horizontal slice stoping-filling method with pointed pillars. The synergetic support principle of pointed pillar and backfill before roof contact was analyzed in the light of charac- teristics of slice filling; the action mechanism of backfill on pointed pillar and the vertical stress ana- lytical method for a pointed pillar with slice filling was deduced, on which basis pointed pillar was op- timized into a new shape of wide-bottom-narrow-top cone. With Liguanji iron mine for an example, the stress distributions and support result of pillars with different filling heights and four different shapes-square pillar, rectangular pillar, circular pillar, and cone pillar are analyzed through numerical simulation. The results have shown that the load area of the cone pillar conforms to the law of vertical stress and shear stress distribution： the load area is largest at the bottom when the vertical stress and shear stress are maximal; as the filling height increases, the load area and the contact area between pillar and backfill decrease proportionally, which can effectively reduce the down-pull effect. The cone pillar can ensure the stability of goaf as well as the decrease of ore loss rate.
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2017年第2期295-301,共7页
Journal of Mining & Safety Engineering
基金
国家科技支撑计划项目(2013BAB02B08)
关键词
点柱
充填体
“下拉”效应
垂直应力
下宽上窄
pointed pillar
backfill
down-pull effect
vertical stress
wide bottom and narrow top
