Development of a Prototype Model to Establish an Economic Earthwork Plan that Includes the Selection of a Dump Site/Borrow Pit

Earthwork in road construction projects is the major activity that accounts for about 20%–30% of the total construction cost, and the internal/external hauling plan is the key factor for determining the successful completion of the project. However, the hauling plan at the site, which includes the selection of the dump site and borrow pit, is usually determined by the site manager’s subjective and empirical discretion alone. Therefore, this study has developed a prototype model that provides the optimal internal/external hauling plan. It includes the determination of the most economical dump sites and borrow pits (location and number) among other candidate sites as well. The transshipment problem theory is incorporated into the optimized algorithm with the consideration of various factors affecting earthwork cost. Direct costs from an optimized transport based on an existing model against another from this model were compared to prove its feasibility. As a result, the reduction of earthwork cost including the dump site/borrow pits reached 4%–8%. This result implies that this prototype model would also be useful in reducing both the earthwork cost and the occurrence of exhaust gas from earthwork equipment by providing optimized transportation paths.