Computational Simulation of Mechanized Tunneling as Part of an Integrated Decision Support Platform

Abstract

Mechanized tunneling is characterized by a staged procedure of excavation and lining erection and continuous support of the soil by means of supporting fluids (or compressed air) at the tunnel face and pressurized grouting of the tail gap. The interactions between the tunnel boring machine (TBM), the support measures, and the soil, including the groundwater, determine the efficiency, safety, and effects on the existing infrastructure. In this paper, a process-oriented numerical simulation model for mechanized tunneling and its integration in the context of an integrated optimization platform for tunneling (IOPT) is addressed. The simulation model is based upon the finite-element method and considers the transient excavation process and all relevant components, support measures, and processes, along with their interactions during tunnel advance. In particular, the model allows the investigation of the effects of drilling and stand-still periods upon the generation of a filter cake at the tunnel face. This is demonstrated by the numerical analysis of a straight tunnel advance by means of a hydroshield machine in water-saturated soft soil.