It has outlined the law of geometry formula computation as well as the formula derivation of the coal amount among the range of protecting coal column,has pointed out the superiority of this law comparing with the traditional method.

• 概述了保护煤柱留设的几何公式计算法以及保护煤柱压煤量公式的推导,与传统方法作了类比,指出此法的优越性。