厚松散含水层薄基岩下综放工作面安全评价

Safety Evaluation on Thick Loose Aquifer under Thin Bedrock Fullymechanized Working Face

在厚松散含水层薄基岩下综放开采时,工作面上覆岩层通常不形成"三带"特征,而仅出现"两带",基本顶易全层切落,出现台阶下沉现象,造成采场矿压显现异常剧烈,导致工作面突水溃沙等灾害发生。为此结合某矿87采区的实际条件,建立安全评价模型,通过定性、定量的评价方法对其进行安全评价。研究得出:在厚松散含水层薄基岩下综放开采,当留设防塌煤柱高度为16.9 m,工作阻力为8 000 k N的液压支架时,安全评价等级较好,可以安全回采。

When caving mining on thin bedrock level under thick loose aquifer, overlying strata failure can not form a masonry beam hinged structure because of bedrock thinner. It shows a suspension arm broken forms. When rock roof falls, it easily lead to a stronger pressure phenomena. The loose aquifer has a function of load transfer, it can pass on the load of the overlying topsoil. Therefore it can happen movable platen and sand inrush of water inrush accident easily during the mining period. According to practical in 87 district of a mine conditions and the theory of mining pressure and strata control, based on the basic theory of safety evaluation ,building the safety evaluation model, assessing it by the safety evaluation method qualitative and quantitative. Caving mining on thin bedrock level under thick loose aquifer,when the height of collapse pillar is 16.9 m and the working resistance of hydraulic support 8 000 kN, the grad of safety evaluation is better ,it can be caved safelv.