Quantitative contrast between the methodologies for the volumetric evaluation with cross-sections and 3D models in tunnels excavated with explosives

Abstract

This research aims to establish the differences that are produced when calculating the volume of the excavation of a tunnel by means of equidistant cross sections obtained from a 3D model, and the 3D model itself, which was obtained from laser scanner data. The purpose of this research intends to contrast numerically a methodology that has been traditionally applied (cross-sections), and a more recent one which is supported by the use of powerful calculation algorithms that are appropriate for 3D models. All this research is applied to a tunnel that is used as spillway of a large dam that serves to regulate the water of a hydraulic facility. The results of this work justify in a quantitative way that, compared to the modern approach, the classical methodology produces deviations that can reach the 10% of the total volume of the excavation, which implies very high expenses, given the costs of this kind of work.