Korelasi point load index dan uniaxial compressive strength formasi kampungbaru daerah batuah site PT karya putra borneo kabupaten kutai kartanegara provinsi kalimantan timur

This study aims to determine the correlation between Point Load Index (PLI) and Uniaxial Compressive Strength (UCS) values in the Kampung Baru Formation located in Batuah Village, PT Karya Putra Borneo Site, Kutai Kartanegara Regency, East Kalimantan Province. The research employed a quantitative method through laboratory testing of rock samples consisting of coal, claystone, and siltstone. The tests conducted included physical properties, Point Load Index (PLI), and Uniaxial Compressive Strength (UCS). Data analysis was carried out using simple linear regression to determine the correlation between PLI and UCS values for each lithology. The results showed that the average PLI values were 0.2180 MPa for coal, 0.2491 MPa for claystone, and 0.1422 MPa for siltstone. Meanwhile, the average UCS values were 7.17 MPa for coal, 2.47 MPa for claystone, and 0.29 MPa for siltstone. The correlation between PLI and UCS demonstrated a very strong positive linear relationship with coefficients of determination (R²) of 0.9899 for coal, 0.9655 for claystone, and 0.8834 for siltstone. The regression equations obtained were UCS = 25.247(Is50) for coal, UCS = 9.4572(Is50) for claystone, and UCS = 2.0523(Is50) for siltstone. These findings indicate that the PLI value can be used as an estimation method for UCS values in the study area.