When the mining area enter the end stage, the optimization design of final block section and uphill pillar recovery are important.
采区进入收作阶段，最后块段与上山煤柱回收的优化设计、合理开采尤为重要。
2
The utility model provides an ultrasonic fault detection comparing test block for a high-voltage pillar porcelain insulator, consisting of a test block body and arc grooves.
本实用新型提供一种高压支柱瓷绝缘子超声波探伤对比试块。
3
Under arraying rope pillar function, two pieces of pulley block circles pillar to do left, right nimble swinging, which cause rope winds in regular arrangement.