An assessment method for fine-grained sedimentary materials excavated by EPB TBM

The aims of this study are to find a solution for the problems (lumping, adhesion, and clogging) encountered with fine-grained sedimentary materials, minimize the time and cost of excavation, and decrease the potential environmental effects due to soil conditioning chemicals used in the process of excavating a waste water tunnel. Therefore, this study will contribute important technical knowledge regarding design and implementation of excavation with TBM to the mining and construction industries as well as for optimization in mechanical engineering.
In this research, real-time machine operational parameters recorded by EPB TBM and actual geotechnical parameters in an Istanbul-Büyükcekmece Wastewater Tunnel at seven selected tunnel sections were used as input data for the back analysis and assessment method. The method covers excavated materials with: (1) water and (2) soil conditioning chemicals. The influence of water and soil-conditioning chemicals of different proportions on torque, thrust, advance rate of the TBM, and plasticity and consistency indices of the material were investigated. Finally, integrated data were evaluated by multiple linear regression models.