ABSTRACT

Tunnel Boring Machine (TBM) is one of the most efficient methods for underground excavation. The estimation of the performance of TBM requires accounting for a large number of factors like geology, machine design and configuration, and operations. Simulation of tunnel activities considering TBM to be a tunneling factory can be a reliable method for estimation of TBM utilization factor. The subsurface geotechnical conditions that control machine penetration rate and muck transportation system are the two most important technical factors affecting the overall performance of the machine in a routine operation. This paper focuses on establishing the impact of geology on the muck transportation system to observe the interdependence between TBM penetration rate and transportation delays. The muck haulage system should be designed to incorporate the changes in the excavation rate in different geology to minimize related delays. The simulations were performed using discrete event simulation software, ARENA, where various tunnel activities were modeled in their relevant sequence with varying geological conditions. The simulation accounts for the number of trains and addition of California switch to examine the impact of the setting on transportation-related delays in various formations.