The most difficult problem of drilling in hard and compact rocks is that drilling efficiency is very low.

Optimized design and tests were made on bit matrix formula,diamond parameters and bit nozzle to overcome slow drilling footage and short service life of the wire-line coring bit in hard and compact rock formation,the newly developed bit(S77),with good adaptability,overcame the drilling "sliding" in extra-hard to hard and mid to weak-abrasive rock formations.

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.

According to the energy-delivering model of the drilling steel in super-hard rock, This article adopts ANSYS three dimensions simulation finite element analysis(FEA) software and the methods of the dynamics harmonic analysis, has analyzed the stress state and deformation of the “Flying Dragon” series number ZQ25-2041 integral drilling steel when it bears percussive stress wave.