Abstract

This paper evaluates blastability characteristics of dolomitic marble and granodiorite for explosive selection. The rock samples were tested in the laboratory for point load strength index, uniaxial compressive strength and specific gravity. Also, joint spacing and joint orientation were measured on the field. Blastability index was estimated for both rocks using empirical equation. The results of the various analyses revealed that point load strength index of dolomitic marble is 3.52MPa and that of granodiorite 4.37MPa. The uniaxial compressive strength of dolomitic marble and that of granodiorite are 93.57MPa and 116.40MPa. The specific gravity of dolomitic marble and granodiorite are 2.72 and 2.75. The porosity of dolomitic marble and granodiorite are 0.72% and 0.63%. The results of Blastability Index (BI) are 55.55 and 57.88 for dolomitic marble and granodiorite respectively. The joint orientation for dolomitic marble and granodiorite is 23.90°/142.83° and 26.83°/116.40°. Based on the results obtained for both rocks high explosives (ANFO) is selected for the rocks but where there is water problem emulsion is recommended.

Keywords:Explosive; Blastability; Rocks; Strength; Dolomite