An evaluation of fine grained sedimentary materials in terms of geotechnical parameters which define and control excavation performance of EPB TBM’s

• Excavation of fine grained sedimentary soils by EPBM was examined in tunnel route.
• Clay morphology is significant determiner in tendency to lump-form and adhesion problems.
• Increase of problems due to ground conditions increases specific energy and tunnel foam consumption.
• Geotechnical and TBM excavation data were evaluated by multiply linear regression method.
• A reliable numerical predicting is provided for EPBM advance rate, based on torque, plasticity index and clay content.

Studies have been conducted on Istanbul-Büyükcekmece Waste Water Tunnel route in order to determine the influence of plastic behavior and adhesion potential of fine grained clayey sedimentary soils as well as the lump form effect on the EPB-TBM’s excavation performance. This research was designed to develop data modelling methodology for a risk assessment of excavating in form of lumps, the adhesion problem on the metal surfaces, and clogging.Back analysis was carried out by linking advance rate (mm/min) data with geotechnical properties of the excavation material. The influence of water and other conditioning chemicals in different proportions on the plasticity index and consistency index of the material was also investigated. In this research, material samples from 14 different points between 1285 and 2186 m of Büyükcekmece Waste Water Tunnel (6.09 km in total length and 20–40 m in depth) that was being excavated in sedimentary clayey materials of Gürpınar formation with an EPB-TBM (Ø = 3.45 m excavation diameter) were evaluated.