عنوان مقاله [English]
In the phase of the design of a TBM, it is essential to optimize the cutterhead characteristics with respect to cut and cutter geometry parameters in order to maximize both cutter penetration and TBM advance rate. In this regard, valuable results have been achieved from numerical simulations and laboratory tests, however due to presence of some shortcomings for such methods (e.g. high difference between rolling force measured in laboratory and actual field data), there is a high demand by the industry to conduct actual field data analyses. So far, very few efforts have been made to study the optimum cutter performance based on the information of completed tunnel projects from around the world. To investigate the influence of various parameters on the cutter penetration and to provide basic guideline for the evaluation of the optimum TBM performance in hard rock conditions, an extensive field database is compiled.
On the basis of the data analysis of this database, it is found that the linear speed of the cutters has a direct correlation with two major parameters of normal force index (NFI) and rolling force index (RFI). In this regard, two formulas are generated using statistical analysis of the data from around 260 tunnel projects to evaluate these indices. The corresponding formulas have coefficient of determination of 77 and 68% respectively. These formulas are used in an optimization process to maximize cutter penetration using the interaction of various operational constrains. The produced interaction diagram is called force-penetration interaction diagram.