resistant rock

For medium-thick and moderately stable ore- body,being laid preliminary projects in ore block footwall,with medium-longth hole blast,ideal effect was ob- tained in the recovery,reference value was also provided for moderately stable pil.

使用中深孔爆破法进行回收,取得了理想效果,也为顶板中等稳固的同类矿山提供了参考价值。

According to the virtual connection phenomenon caused by easy escape of plug-in protection electronics in the box under coal mine, which makes switch fail to work, this paper analyzes theoretically the position of plug-in electronics and provides methods to increase the stability of plug-in electronics and reliable measures to ensure the working of switch.

根据煤矿井下箱内电子保护插件的插脚易脱造成虚接触现象,使得开关不能正常工作,文章对安置方位的插件进行了理论分析,并提出了增加插件稳固性方法,以保证开关工作的可靠性措施。

The effect on track of the deployed number of concrete sleepers within per kilometer are calculated and analyzed in detail based on the track strength theories(including static and dynamic) and the track stability theory, thus to find the theoretical base for the decrease of the deployed number of type Ⅲ concrete sleepers per kilometer.

以轨道强度理论（包括静态和动态）及线路稳固性为基础，综合计算、分析了混凝土轨枕配置根数对线路的影响。