煤矿深部巷道底臌发生机理及防治对策研究

在假定底板围岩为服从Coulomb屈服条件的理想刚塑性材料的基础上, 对剪切型底臌发生机理进行了分析, 认为剪切型底臌发生时存在一个临界剪切滑移面, 且此滑移面上围岩将达到抗剪强度极限值。根据剪切型底臌底板围岩受力特点将滑移面上底板围岩分为主动区、被动区、过渡区, 建立了底臌的计算力学模型及分析简图, 通过引用等效传递荷载方法推导了巷道底板塑性区发展深度的解析计算式, 然后以某巷道为研究对象, 经解析计算与数值仿真分析的对比研究, 发现两者结果具有一定拟合性, 验证了解析计算方法的有效性, 由此提出了顶板控制和增强滑移面剪切强度的巷道底臌控制方法。以淮南矿业集团新庄孜煤矿66210风巷为工程背景, 对底板底臌发生机理及塑性区发展深度解析计算式进行了分析, 提出了补打底角、帮脚锚杆、施加顶板锚索、底板注浆等具体的底臌防治措施, 工程监测结果显示上述支护措施取得了较好的经济技术效果, 为剪切型底臌的治理提供了借鉴指导意义。

Mechanism and Countermeasure for Floor Heave of Deep Coal Mine Roadways

Assuming surrounding rock in the floor is rigid-perfectly plastic material subjected to Coulomb yield criterion, the mechanism of floor heave by shear damage was analyzed. It is found that while floor heave occurred by shear damage, there existed a sliding plane where the shear strength of surrounding rock reached a critical value. Based on the mechanism of floor heave, the zone of surrounding rock can be classified into three types, such as active zone, passive zone and transition zone. A mechanical model for the floor heave and its analytic calculation diagram are established. An analytic formula for the depth of plastic zone is deduced by equivalent load method. Taking some real roadway as an example, it is found that results are coincident with analytic calculation compared with numerical calculation, which verifies the effectiveness of this analytic calculation method. Consequently, it is proposed that floor heave can be prevented by roof control and increasing the shear strength of sliding plane. Analysis was made for the 66210 wind-roadway in Xinzhuangzi Coal Mine of Huainan Mining Area. Reasonable suggestions, such as applying sides and floor anchor, applying top cable and grouting in the floor, are put forward. The monitoring data indicates that these methods are effective and economical, which is of significance in guiding the treatment of floor heave.