controlled roof distance

• 控顶距

controlled roof distance的用法和样例：

例句

1. By the same method we also obtain the distribution of the lunar zenith distance versus the occurring probability of earthquakes.
   同样的方法，可得地震的月球天顶距地震频度分布。
2. This paper introduces the determination of the calculating formula of the empty-support distance of headwork in the tunnel with large sections by using the plate theory.
   文章介绍了利用薄板理论确定大断面巷道掘进期间的空顶距计算公式。