The coal seam tunnel of compound mudstone roof of large span is the tunnel that is violent out of shape, roof is easy falling and safeguard is very difficult.
大跨度复合泥岩顶板煤层巷道是围岩变形剧烈且顶板易冒落、极难维护的巷道。
2
It analyses quadratic phase stainless and its metal compound generated from weld seam and HAZ, which affect welded pipe usage property.
分析了双相不锈钢及其焊缝和热影响区中产生的金属间化合物等二次相对焊管使用性能的影响。
3
The internal stress is consisting of circumferential stress and axial stress, from which the compound stress of the weld seam is derived.