Predicting Excavation Performance of EPB TBM by Using Soil Properties: A Case Study of Dudullu Bostanci Metro Project

This study was conducted to determine the effects of soil properties on the excavation performance of an earth pressure balance tunnel boring machine (EPB TBM) used in the Istanbul Dudullu-Bostanci Tunnel Project. Soil samples were collected from different locations along the tunnel route, and subjected to laboratory tests to determine the particle size distribution, natural water content, consistency limits (liquid limit, plastic limit, plasticity index, and consistency index), fall cone penetration depth, unified soil classification, and clogging potential. The field performance data were obtained from the EPB TBM data logger. Data analysis was carried out by statistically linking the TBM thrust force, and instantaneous cutting rate, with the geotechnical properties of the excavated soil by using single and linear regression methods. The results indicate that the fall cone penetration depth can be used for predicting the thrust force, the plastic limit for the instantaneous cutting rate, and the plastic limit and plasticity index, as well as the consistency index, for field-specific energy predictions. Additional studies are required to provide more reliable and generalized prediction models, by increasing the number of laboratory and field tests for different soil types and performance data for different EPB TBMs.