Analysis of TBM Performance in Two Long Mechanized Tunnels, Case History of Karaj Water Conveyance Tunnel Project Lots 1 and 2 (Iran)
Analysis and assessment of TBM performance during construction and comparing the field performance with the predicted values is important in optimization of tunneling activities. This includes the analysis of rate of penetration and machine utilization factor as the main focus of such studies. This paper offers an overview of TBM performance in Lot 1 and 2 of Karaj water conveyance tunnel project for a length of 30 km located in northwest of Tehran. Study of monthly utilization and rate of penetration for both tunnels shows that AR fluctuates are more susceptible to U than ROP. Statistical analysis of the data indicates that activities such as Maintenance, TBM Breakdowns, shift changes, segment installation are more influential than surveying and re-gripping in determining machine utilization. Therefore to optimize AR and U one can focus on the critical items.