Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Strength Evaluation of Rocks in Amata-Lekwesi, Eastern Nigeria Using Diamond Coring Bit Penetration Rate
by Ngerebara, O. D., Aitsebaomo, F. O., Teme, S. C, and Abam T. K. S.

Abstract:
Basic igneous rocks within Amata - Lekwesi Area in Eastern Nigeria is believed to have intruded the Cretaceous Eze Aku and Asu River group shales in dyke - like and dome - like structures in different parts of the region. This study classifies the rock strength in Amata-Lekwesi area based on in-situ properties. Eleven holes were drilled to a depth ranging from 15-25 meters and were probed over an area of 81,750m2 using Slanzi Diamond rotary rig. Each drill hole was cored continuously and samples retrieved at every 1.50m interval. Coring covers both the host country rock (shale and shaley carbonate) and the intrusive (where both are encountered in the same hole). Specific energy of the cored materials was determined using a standard thrust (F) and torque (T) on the rotary drill. Rock strength evaluation was therefore made based on the drill penetration rate (u), total percentage recovery (TPR), and the rock quality designation (RQD).The results so obtained compared favourably with uniaxial compressive strength for similar rock types elsewhere

Keywords: specific energy, rock strength, drill penetration rate, total percentage recovery, rock quality designation, uniaxial compressive strength.

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