Proposição de fatores de conversão de volumes em terraplenagem para a Região Metropolitana de Fortaleza

Abstract

The earthworks consists of the modification of the natural terrain in order to promote the structural and geometric adequacy that it needs to receive the enterprise. The main earthworks services are related to the execution of cuts and fills. During this process, soils have different densities due to volumetric variation. The volume conversion factors represent the relationship between cut, loose and fill densities. In general, the choice of volume conversion factors is made arbitrarily, based on the engineering experience and the use of values found in the literature. However, this practice can result in misleading values in the calculation of the earthworks, causing delays in the schedule and extrapolation in the budget of the work. In view of the foregoing, it is proposed the regionalized study of soils in order to obtain and measure the volumetric conversion factors for the soils of the Metropolitan Region of Fortaleza. In this studies, to obtain the densities in situ and in the loose state, field and laboratory tests were carried out. Compacted soil density was obtained through a database elaborated in other studies. In addition, correlation analyses were performed between volumetric variation and other properties of the studied soils. It was verified the existence of correlation between the percentage of fines and swelling, between in situ density and swelling and shrinkage, and between the plasticity index and shrinkage. A cost sensitivity analysis was also performed, where we sought to analyze the variation in the cost with the execution of a fill as some parameters are changed, these being the transport distance, the type of soil and the volume conversion factors adopted. Finally, the results obtained for the volume conversion factors, as well as the correlation analysis, were consistent with the literature.