大断面回采巷道层状底板底臌机理及其防治对策

为研究大断面回采巷道底臌机理并寻求控制底臌的有效对策,通过对大断面回采巷道层状底板底臌机理进行理论推导,提出该类底板底臌的预测方法。结果表明:随着回采巷道底板断面的增大,岩梁的临界应力逐渐减小,更易失稳破坏;在水平力的作用下,几乎所有大断面回采巷道均受到底臌的威胁;随着巷道宽度的增加,底臌量大致呈线性增加。同时对巷道一般支护、加固巷道帮角和顶板及在加固巷道帮角和顶板的基础上安装底板锚杆的3种支护方案分别进行数值模拟,发现加固巷道帮角和顶板的同时安装底板锚杆可更好的防治底臌。

Mechanism and countermeasures of layered floor heave of large section mining roadway

In order to study the mechanism and effective countermeasures of floor heave in large section mining roadway，one of its prediction methods was put forward through theoretical deduction.It is showed that floor rock beam with lower critical stress is easier to instability，along with larger section of mining roadway.Almost all large section roadway are subject to the threat of floor heave under horizontal force.Moreover，with the increasing width of tunnel，the heave volume increases approximately linearly.At the same time，three kinds of support scheme，roadway support，reinforcement of sides，corners and roof，were analysed with Ansys.A conclusion is drawn that floor heave can be controlled well by installing roof bolting based on floor on a small scale with the reinforcement of working slope，angle and roof.