The effect of mineralogical and textural characteristics on engineering geological properties of Alvand granitoids and hornblendgabroo (southwest Hamedan)

Granitoid and Hornblend gabroo rocks of Alvand area show a variety of engineering geological properties that may affect quarrying operation, tunneling, mining, slope stability and use of rock as construction materials. The physical and mechanical properties are functions of the mineralogical and textural characteristics of rock. The purpose of this study is to apply correlation analysis to investigate the relationship between petrographical and engineering geological properties of rocks. For this research, 90 rock samples (Granitoids and hornblend gabroo) from Alvand mountains (southwest Hamedan) were subjected to petrographic studies. The same samples were then tested to determine solid specific gravity, dry and saturated unit weight, water absorption and total porosity. Schmidt hardness, point load strength index, uniaxial compressive strength, modulus of elasticity and Linear Crack Density Index (LCDI). The relationships between these properties and the petrographic characteristics are described by simple regression analyses. The study revealed that the influence of the textural characteristics on the engineering geological properties appears to be more impotant than the mineralogy. It also determined that the type of contacts, grain (mineral) shape and size significantly influence the engineering geological properties of these rocks.