compound rock meaning in English

复矿岩

Key strata is a rock seam which plays an important controlling roles in the movement of mining overlayer strata while the key strata is sometimes made up of two or more compound rock strata
摘要在采场覆岩运动中起主要控制作用的岩层为关键层，而有时关键层是由2层或2层以上岩层形成的复合岩层所组成，我们称其为复合关键层。
According to the deep analysis on the formation mechanism of compound rock strata , the mechanical condition of compound rock strata formation and the related formula are obtained to build up the differentiate method of the compound key strata in the coal face strata and the corresponding differentiate program is made
本文在深入揭示复合岩层形成机理的基础上，给出了形成复合岩层的力学条件与数学表达式，进而建立了采场覆岩中复合关键层的判别方法，并编写了复合关键层的判别程序。