联合采矿法回采挂帮矿时采空区的临界冒落跨度研究

露天转地下过渡期挂帮矿开采方法有多种,其中联合开采是解决过渡期产量平衡的有效方法。使用联合采矿法会形成非连续的采空区,这些采空区将影响矿山的安全生产,因此,需要研究安全合理的空区处理方法,诱导冒落法是近几年兴起的一种新型空区处理方法,采用诱导冒落法时需要提前确定采空区的临界冒落跨度和散体垫层的安全厚度,文章结合某铁矿挂帮矿体的实际情况,首先利用解析法计算出空区的临界冒落跨度和散体垫层安全厚度,然后通过数值模拟对矿柱回采过程中空区顶板围岩的位移、应力进行分析,补充验证了采空区的临界冒落跨度,并证明了采用此方案处理采空区的可行性,对矿山的生产施工具有一定的指导意义。

Research of Critical Caving Span of Gob in Stoping the Hanging Wall Ore with Combined Mining

There are many kinds of mining methods of hanging wall ore during the transition period of open-pit to underground, in which combined mining is the effective method of solving the output balance during the transition period. Employing the combined mining method can form the discontinuous gob which will influence the safety production of mine, so it is necessary to study the safe and rationale gob processing. The induced caving is a new rising type of gob processing method in recent years. When adopting this way, there is necessity for ensuring critical caving span of the gob and safe thickness of the bulk solid cushion layer in advance. This paper combines the actual situation of hanging wall ore bodies of iron mine, firstly making use of analytical method to calculate the critical caving span of gob and the safe thickness of bulk solid cushion layer, and then analyzes the displacement and stress of gob roof surrounding rock by means of numerical simulation in the process of jamb recovery. This not only ensures the validity of the critical caving span of gob further, but also testifies the feasibility of employing this program in processing the gob. This paper has a certain guiding significance for the production and construction of mine.