ABSTRACT
Belpinar irrigation Tunnel of 5450 km in length was opened with an EPB-TBM having a diameter of 6.82 m. The tunnel has a complex geology with serpentinites and peridotites, highly fractured in most cases with water ingress reaching up to 450 l/s. A mean daily advance rate of 8.04 m with stoppages and 9.93 m without stoppages were obtained with a maximum daily advance of 21 m. The mean ratio of compressive strength to tensile strength ratio of the intact rock is extraordinary low changing between 3.8 and 4.1. This enabled to compare thrust index, torque index, penetration and specific energy values obtained in different tunnels in Turkey and classifying the excavability of the rocks according the ratio of compressive strength to tensile strength ratios. The complexity of the rock mass in Belpinar was divided in five parts. The Machine utilization, repairs of the machine, stoppages and disc consumptions were discussed for each part. Some recommendations were made for more efficient excavation for similar complex geologic formations.
