Application of Queuing Theory for Determining the Cost of Earth Moving

Abstract

Earth moving is one of important processes in cost estimating of the construction work. Commonly, it can be seen that small to medium-scaled contractors estimate the unit cost of work from their experience without knowing its real cost. Therefore, this research aims to evaluate the unit cost of earth moving. Collected data pertaining to cost include the ownership and operating costs. A production rate of equipment involves volume of the truck bowl and its cycle time in moving the earth. For this study, the haul distance between the excavating area and the dump site is set at 0.5, 1, 2, 3, and 4 kilometers, respectively. Also, the equipment used for conducting an experiment constitutes one excavator and five trucks. Queuing theory is also applied in analyzing the productivity of the trucks. The results from the study reveal that 4 trucks are the optimum numbers for a short haul distance of no greater than 1 kilometer with an equation of unit cost y = – 0.146x2 + 1.543x + 8.928 baht/m3. Where a haul distance is varied from 1 kilometer up to 4 kilometers, 5 trucks are the most appropriate choice with an equation of unit cost y = –0.054x2 + 0.944x + 9.352 baht/m.3