Modelo de rendimiento de microtuneladoras (MTBM)

From the last decades of the XX century, various formulae have been proposed to estimate the performance in tunnelling of disc cutters, mainly employed in Tunnelling Boring Machines (TBM). Nevertheless, their suitability has not been verified in Micro Tunnelling Boring Machines (MTBM), with smaller diameter of excavation, between 1,000 and 2,500 mm and smaller cutter tools, where parameters like joint spacing may have a different influence. This paper analyzes those models proposed for TBM. After having observed very low correlation with data obtained in 15 microtunnels, a new performance model is developed, adapted to the geomechanical data available in this type of works. Moreover, a method to calculate the total amount of hours that are necessary to carry out microtunnels, including all the tasks of the excavation cycle and installation and uninstallation