roof cross beam
常见例句
- No beded and fractured roof can be treated as an elastic continuous beam, when it consists of rock blocks formed by cross joints and fractures. In fact, it, as a mechanic structure , is an arch.
受采动裂隙和节理切割的层状破裂顶板不能视为弹性连续梁，其力学结构应为岩块相互挤压而成的压力拱。 返回 roof cross beam