Assessment of TBM performance in tunnel excavation (first lot of Karaj - Tehran water conveyance tunnel)

Karaj - Tehran water conveyance tunnel (LOT1) was excavated by TBM with 4.66 m diameter whereas the utilization factor is different with tunnel length. According to geological condition, excavated length and personal skill, TBM performance has been compared in four equal parts of tunnel. Evaluation of TBM Activity and delay time shows that in addition of specified factors, the utilization factor also depends on the overlap of activities. In this project utilization factor for every part is 18.30, 22.26, 16.09 and 16.08 respectively.