Improved Method for Locating Centroid of Earthwork

Location of the centroid (center of mass) of a cut or fill section is needed in roadway earthwork allocations which are designed by the mass‐haul diagram (MHD) and optimization methods. In the MHD, the centroid location is approximated by the point at which there are equal volumes of earth on both sides of the point. In optimization methods, the location is approximated by the midpoint of the section. This paper develops a method for determining more accurately the centroid location of an earthwork section with a level ground across the roadway centerline. The height of the earthwork section is approximated by a second‐degree polynomial and the centroid location is determined based on the moment principle. Special cases in which the section is prismoid, wedge, and prism are presented as well as extensions to accommodate some practical situations. The method is applied to a numerical example and the results show that the method provides considerable improvement over the traditional methods.