Bearing Capacity Prediction of Mine Hauling Road Using Cone Penetration Testing (CPT)

Abstract

Mine hauling road plays an important role in open pit mining that serves as the main link for transports to significant locations, such as connection from pit/quarry – crusher – stockpile/rom – jetty. Inadequate bearing capacity could result in construction failure of the haul road, therefore it is important to understand the bearing capacity of the sub base layer along the determined haul road route. Cone Penetration Test (CPT) was utilized to obtain the insitu geotechnical data used for determining the haul road bearing capacity. Results show that the occurrence of hard layer along the haul road route varies from the depth of 3.40 (CPT12) to 12.20 m (CPT06). Calculated bearing capacity of the sub base layer shows varying results along the road route. Minimum ultimate bearing capacity (qul) of 430.49 kN/m2 is found in CPT-06 site with allowable bearing capacity (qall) of 215.24 kN/m2. While maximum ultimate bearing capacity (qul) occurs in CPT-04 site of 2058.71 kN/m2 with the allowable bearing capacity (qall) of 1029.35 kN/m2. The calculated average ultimate bearing capacity (qul) is 1151.47 kN/m2 and allowable bearing capacity (qall) 575.74 kN/m2. It is suggested that the type of dump truck used for hauling should have tire pressure less than or equal to 575.74 kN/m2, in order to maintain the road during mining lifetime and prevent road deterioration.