basic roof

常见例句

Basic roof and immediate roof of horizontal section top coal caving were beside the working face in steep seams.
运用弹性薄板理论对急斜煤层水平分段放顶煤开采基本顶岩层进行拉应力分析，得出了顶板破断的判别准则。
By using the mechanics theory to analyze the character of roof moving and deformation after coal mining, the conclusion is gotten that the basic roof will not fail.
并运用相关的力学理论，分析置换开采后顶板的运动和变形特征，得出基本顶不会破断，地表变形没有超过建筑物允许变形范围。
The result shows that the weighting of pillar-wall mining is great for the basic roof, uniform for working face, and moderate or a little greater than moderate in middle area.
柱壁式综采法是在已掘巷柱式采区内布置长壁工作面，并用综采成套设备回采的采煤技术。