Effect of Sandstone Compressive Strength Value on Differences in Physical Conditions in Samarinda City, East Kalimantan Province

Abstract

Rock strength is the ability of a rock to maintain its strength until it breaks when given force. The purpose of this study is to determine the comparison of rock strength values in different physical conditions, namely natural, saturated, dry conditions and 2 wet-dry cycles on sandstones by testing uniaxial compressive strength according to SNI standards 2825-2008. The results of compressive strength testing at two different locations showed that the condition of the rocks around the Samarinda region was weak to moderate, with strength values at location 1 ranging from 1.61 – 14.31 MPa and at location 2 ranging from 8.26 – 36.27 MPa. The Elastic Modulus obtained at location 1 ranges from 1.88 -18.60 and at location 2 it ranges from 8.26 – 37.928. The more to the West from the city of Samarinda, the strength of the rocks is increasing. With the treatment of rocks that undergo repeated wet-dry processes, it does not cause a decrease in rock strength compared to the condition of rocks undergoing saturation. This is because the amount of water content that is large enough in saturated conditions results in weakening of the rock. The lower the water content, the stronger a rock.