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.
受採動裂隙和節理切割的層狀破裂頂板不能眡爲彈性連續梁，其力學結搆應爲巖塊相互擠壓而成的壓力拱。 返回 roof cross beam