TY - JOUR ID - 86 TI - Evaluation of TBM Utilization Using Rock Mass Rating System: A Case Study of Karaj-Tehran Water Conveyance Tunnel (Lots 1 and 2) JO - Journal of Mining and Environment JA - JME LA - en SN - 2251-8592 AU - Frough, Omid AU - Torabi, Seyed Rahman AU - Tajik, Majid AD - Shahrood University of Technology AD - Shahrood Uni. of Technology AD - SCE Y1 - 2012 PY - 2012 VL - 3 IS - 2 SP - 89 EP - 98 KW - Ground conditions KW - RMR KW - Utilization KW - TBM downtimes KW - Karaj water conveyance tunnel DO - 10.22044/jme.2012.86 N2 - Successful application of a TBM in a project requires investigating both the ground conditions and the machine and backup system design features. Prediction of the machine performance is very important as it has a big effect on the duration of the project and the costs. In this respect, both penetration rate and advance rate must be estimated. Utilization factor, which depends on the type of operation, management, maintenance, geological conditions, mucking delays and other downtimes, correlates the advance rate and penetration rate. Adverse rock mass conditions such as mixed face condition, water problem and instability of rock have a great role in TBM downtimes and reduce the machine utilization considerably. Based on  detailed engineering geological reports and maps and daily site reports taken from Karaj-Tehran Water Conveyance Tunnel ( Lots 1 and 2), this paper evaluates, main rock mass properties utilized for the estimation of TBM performance and discusses their effect on the machine utilization. . More specifically it uses the developed database also contains daily boring time, different rock mass related downtimes, daily advance and length of bored tunnel in each engineering geological units. It is concluded that the percentage of the rock mass related downtimes can be estimated via RMR within reliable coefficient of determination. UR - https://jme.shahroodut.ac.ir/article_86.html L1 - https://jme.shahroodut.ac.ir/article_86_37947d0b6e5d16bc78d6c44fc0d2b66c.pdf ER -