Productivity of Tunnel Construction Using Road-Headers

Abstract: Mechanical excavation of tunnels using Road-header is getting widespread and popular due to their capability of excavating precisely soft to medium strength rock without weakening the surrounding rock. Road-header is flexible, very mobile, safe, and environmentally friendly machinery. It can excavate smoothly various sizes, shapes, and types of tunnel openings. Accurate and reliable productivity prediction for the selected machinery is required for time and resource scheduling, and hence estimating the budget of any tunnelling project. Simulation can be used to study tunnelling operations using Road-headers before they are actually performed. It will assist decision makers to predict productivity and to control time, cost, and resources. This paper presents a simulation model for estimating a (Voest-Alpine) Road-header productivity using both MicroCYCLONE and EZSROPE Software. Two Road-headers are used to excavate 1.2 km tunnelling project starting Henri-Bourassa Station to Cartier station in Montreal, Quebec, Canada. The collected data represent actual time duration for the tunnelling operations (drilling, changing bits, maintenance, scaling, and wire mesh installation) of each Road-header. The results show that the predicted productivity by both simulation models gives close results to the actual. Productivity is calculated as 0.44 lm/hr for the Road-header used in Henri-Bourassa direction against 0.48 (actual); while it is 0.64 lm/hr for the Road-header used in Cartier direction against 0.7 (actual). A regression model is developed to generate a formula to predict the productivity (advance rate) based on consumption bits. The study also includes a sensitivity analysis for the resources acquired in tunnelling operations