Abstract: In order to identify roof strata in the process of excavation, a measurement method used to detect roof strata by means of pressure and quantity of flow in hydraulic system of bolter has been presented. Calculation formulas of drilling parameters have been deduced. Test system has been built to detect roof strata along with drilling. Drilling data have been compared and analyzed with uniaxial compressive strength (UCS). The research results have shown that: 1) It can be inferred that drills bit has passed though rock interface or weak interlayer accordingly while a step or pulse change of pressure and flow in hydraulic system of bolter has been detected. 2) Tests have measured that the ratio of maximum and minimum value of penetration rate is 12.4 when drills bit passing through weak interlayer, which has shown that penetration speed is the most sensitive one among several drilling parameters. 3) Strata strengths and position of roof strata can be calculated by detecting pressure and flow in hydraulic system of bolter.

Key words: roof strata, excavation roadway, identification along with drilling, weak interlayer