一、引言在煤矿长壁开采中,掩护支架上方与端面发生的冒顶事故仍是顶板管理的一个主要问题。特殊环境下正确选择掩护式支架型号是很重要的,但不能永远保证具有良好的顶板控制,因为只有正确使用这种支架才会取得更好的效果。在比利时煤矿对20个长壁面8种不同型号掩护支架的性能进行了广泛的测定。在连续20d中,就30个支架测定了其反映支架和顶板状况的各种参数(图1): I. INTRODUCTION In the longwall mining of coal mines, the roof accident at the top and the end of the shield support is still a major issue in roof management. Proper selection of the shield bracket model in special circumstances is important, but it is not always guaranteed that there is good roof control as this bracket will only work better if properly used. In the Belgian coal mine, 20 long-wall 8 different models of shields have been extensively tested for their performance. In 20 consecutive days, 30 stents were measured for various parameters that reflect the condition of the stent and the roof (Figure 1):