Estimating earthwork volumes of curved roadways: Simulation model

Earthwork volumes represent the basis on which contractors are paid for highway construction. The earthwork volumes between successive roadway stations are also used in determining the economic distribution of earthwork. It is essential that the volumes should be accurately computed because disagreements related to earthwork volumes often cause the owner and the contractor to look to the courts for settlement. The traditional model for estimating earthwork volumes of curved roadways (flat horizontal curves) is suitable only for level terrains. For moderately fluctuating terrains, a mathematical model has been developed. This model, however, assumes that the longitudinal ground profile between successive stations is linear and the ground cross slope is constant. The mathematical model is not accurate for greatly fluctuating profiles, such as those in hilly and mountainous terrains. This paper develops a model for estimating earthwork volumes for such profiles using Monte Carlo simulation. The paper illustrates how a completely deterministic problem can be solved using a probabilistic simulation. The results show that the simulation model improves the estimates of earthwork volumes compared to traditional and mathematical models.