Adaption of the Kaufman and Ault method for mining haul road design using extruded polypropylene geogrids

Abstract

The present work proposes an adaptation of the Kaufman and Ault methodology for the design of mining unpaved roads, incorporating the effects of reinforcement with multidirectional polypropylene geogrids. Based on experimental results reported by Adams et al., which indicate an apparent improvement in the CBR index due to the inclusion of geosynthetics, a practical approach was developed to evaluate potential reductions in granular layer thickness. The study presents the methodology for modifying the original design procedure and discusses its applicability limits, including minimum CBR values and the validity range of the Kaufman abacus. Guidelines for the appropriate use of geogrids in pavement reinforcement are also proposed. A practical application example is provided to illustrate the proposed methodology and assess its influence on pavement thickness. The results should be interpreted as a preliminary assessment, as the proposed approach is based on analytical adaptation and published experimental data, requiring validation under real field conditions.