The Research On Optimum Analysis And Program Realization Of Earthwork Calculating Methods In Construction Projects

The selection of the methods of earthwork calculation involves not only the calculating efficiency but also the accuracy, which has a direct impact on construction cost and construction management. The thesis, first of all, briefly presents the definition of earthworks, the calculating scope for earthwork volume, and the related research background information. Meanwhile, it lays a special emphasis on the methods of confirming designed elevation and calculating earthwork volume, as well as their present studies, both at home and abroad, revealing that the traditional methods are characterized by poor accuracy, complex adjustment and low efficiency. Thus to calculate earthwork volume using modern computers and cyber technology is advantageous and necessary. The three conventional methods for calculating earthwork volume, namely the cross-section method, grid method and disperse points, together with the corresponding improvement in methods, have also been discussed in the thesis. The author makes a detailed analysis and comparison of the methods in terms of calculating theory, applicable sphere and calculating procedures, and concludes the problems existing in estimating large-scale ground leveling up volume of earthwork. In addition, from the theoretical perspective, the thesis has analyzed minutely the grid method, the most frequently used in calculating earthwork volume in construction projects. It is suggested that the main factors influencing the calculation are the side length of square grid, construction area, scale of the topographical map, contour interval, slope and construction height. The author further puts forward theoretical basis for reasonable selection of the side length of the grid in different situations. Thirdly, the author explains the factors determining the designed elevation and contrasts conventional calculating methods, reaching the conclusion that the defects such as the need for trial, the complicated calculation and great error are inherent in them and least square method can be adopted to optimize the designed elevation and then determine the optimal design plane. Finally, based on the principle of DEM, the paper has touched upon the calculation of the earthwork volume using GIS (MapInfo 8.5plus with Surfer 8.0). After a comparison of the principle and methods of DEM, the author gives a brief introduction of the principle of calculating earthwork volume using GIS software, and has made it adopting MapInfo 8.5and Surfer 8.0. The technological procedures have been summarized and testified in a pilot leveling project, which has gained success.