Characters near strong impact loading zone in hard rock;

Aiming at the problem of poor blasting effects that exists universally in hard rockst,he middle deep hole blasting tests were done in hard rock tunnels at Shuangyang Mine;and the blasting test results of different kinds of cutting forms have been gotten.

This paper expounds the Application of presplit controlled blasting technique in the hard rock blast,and introduces the general situation of the engineering,the design scope,the drill-and-blast technical parameters,the structure of charging and explosive load,the blasting network,and the firing order,etc.

Through analysing the drillability and blastability of hard rocks according to characters of hard rocks, suitable blasting parameters and operation way are selected, and good blasting effect is obtained.

Application of hard rock drilling process at construction of Yanzhou Coal Field;