Pavement Design of Coal Mine Hauling Road in Indonesia using California Bearing Ratio (CBR) data

Abstract

Mine activities in the open-pit method are usually dominated by digging-loading-hauling. This hauling road is the infrastructures that is highly essential in mine area and serve as main linkage some locations. Design of the road requires careful attend in avoidance of failure in construction and disruption in production activities. Field investigations such as insitu CBR testing and laboratory testing (Proctor Modified and CBR laboratory) were chosen to determine the geotechnical parameters of soils that needed in the design of hauling road. The average value of the laboratory CBR testing at 0.1 inch penetration was 16%. The modified type of proctor test comprise some parameters such as the average value of the maximum dry density was 1.64 gr/cm3; the maximum wet density was 1.97 gr/cm3; the average value of dry unit weight was 16.07 kN/m3; saturated unit weight was 19.30 kN/m3; optimum moisture content was 20.2%. The average value of insitu CBR testing at 0.1 inch penetration was 19%. The average load of tire pressures on the front and rear wheels is 7000 lbs. The ability of road to carry the load should have the bearing capacity > 20800 psf = 144.44 psi = 20.95 kPa. The thickness of each pavement layer is as follows: 17 inches of sub grade layer; 2 inches of sub-base course layer; 15 inches of base course layer; 5 inches of surface course layer.