A review on Australian mine haul road design procedures

The cost effective design of Mining Haul Roads is critical to the successful operation of all open cut mines within Australian and around the world. These mines rely heavily on the haul road network to transport run of mine (ROM) material. However, haul roads are often under-designed and seldom constructed and maintained to a standard that minimises total cost. Theoretical methods of Queensland haul road design including pavement design, geometric design and functional design were researched and documented. Using design and as-constructed information obtained from mine sites an analysis was undertaken to determine how different methods of pavement designs presented different configurations. These configurations were run through CIRCLY to calculate the pavement deflection under the vehicle. The calculated deflection was then utilised in an attempt to calculate rolling resistance and the effect on fuel consumption. However the static deflection data produced by CIRCLY was not suitable to use in determining the component of rolling resistance that can be attributed to pavement configuration. Therefore different methods of pavement design were analysed to determine their maximum deflection / deformation under similar load conditions. Designing for minimal surface deflection would suggest that the optimal method to determine cover to subgrade is either Ahlvins Formula with Austroads Sublayering, Ahlvin’s Method with Austroad Sublayering and improved subgrade, or cement modifying the base materials. All of these methods will produce an adequate design while being comparatively costs effective. However it should be noted that none of the methods used achieved deflections near that suggested by Thompson of 3mm (Thompson 2011b) or Tannant and Regensburgs 6-8mm (Tannant & Regensburg 2001). So that irrespective of the method used the rolling resistance will be more than desired. Therefore further onsite testing is required to justify which method produces the least deflection and hence rolling resistance in a practical sense