The Effects of Mineral Size, Texture Coefficient (TC), and Ductility-Brittleness on Creating Hole in Granitic Rock Specimens

Creating holes in rocks using different methods presents various challenges. In this research, an attempt was made to investigate these characteristics and the existing problems in creating holes based on the texture and brittleness of the rock. For this purpose, several core specimens were taken from the Alvand granitic batholith of Hamadan, and the petrological and textural indexes of the rocks were determined. There are four types of rock textures, ranging from coarse-grained to fine-grained. The texture coefficients (TC) for the four types of rocks (G۱ to G۴) were ۱.۷۰۹, ۱.۷۳۰, ۱.۷۷۴, and ۱.۶۹۷, respectively. The brittleness index (B۱) for the four types of rocks (G۱ to G۴) were ۹.۱۳, ۱۱.۰۱, ۱۲.۰۷, and ۱۰.۶۵, respectively. After that, using a diamond drill, one hole was created in each rock core specimen, and at the end of drilling, a fracture pit was separated from the bottom of each hole in the specimen. The results show that as the mineral size decreases, the fracture pit depth also decreases, and in porphyry texture, the fracture pit depth is between the fracture pit depths of coarse-grained and medium-grained rocks. As the texture coefficient (TC) and brittleness of the rock specimens increase, the fracture pit depth decreases, and in porphyry texture, the fracture pit depth remains between the fracture pit depths of coarse-grained and medium-grained rocks. Finally, the results from laboratory tests indicate that creating holes using a drill to study the effect of the holes on rock behavior can cause damage to the rocks.

کلیدواژه ها:

granite ، Rock texture ، Rock Hole ، Texture Coefficient ، Brittleness Index