ملخص الدراسة:

Index physical properties of rocks, particularly density (D), specific gravity (S) and porosity (P), formed an important relation to rock strength. This study attempts to integrate these three properties, according to their relationships through triangular net called (DSP). This triangular net can be used first to elucidate the resultant effects of interrelations of physical characteristics of rocks, and to predicate a scientific rules to study the relation between physical properties and mechanical strength of rocks. Second to represent and estimate the physical properties of various rock specimens. Third to classify different rock types into different groups. Each group is assigned a symbol that consists of three alphabetical letters. Fourth to estimate the suitability of rocks for various uses in the building industry. This use is based upon the zones into which the triangular net was divided. The applicability of this proposed triangular net is tested and the results found quite satisfactory.