An investigation of the relationship between muck geometry, TBM performance, and operational parameters: A case study in Golab II water transfer tunnel

• Published in: Tunnelling and underground space technology Vol. 88; pp. 73 - 86
• Main Authors: Heydari, Sasan, Khademi Hamidi, Jafar, Monjezi, Masoud, Eftekhari, Abbas
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2019; Elsevier BV
• Subjects: Boring machines; Chip geometry; Coarseness; Correlation analysis; Cutting parameters; Drilling & boring machinery; Geometry; Grain size; Machine tools; Mathematical models; Muck size distribution; Penetration rate; Rock cutting efficiency; Specific energy; Thrust; Transfer tunnels; Tunnels; Water distribution; Penetration rate; Rock cutting efficiency; Specific energy; Muck size distribution; Chip geometry
• ISSN: 0886-7798; 1878-4364
• DOI: 10.1016/j.tust.2018.11.043

An attempt was made to examine the relationship between various TBM operational factors, its performance, and muck geometry during the excavation of a short geologically uniform section of Golab II water transfer tunnel. A database based on nine field testing data derived from machine operating and performance parameters along with muck shape and size was formed. Subsequently, it was used for analyzing the correlation among variables. The analysis results point out that there is a strong inverse correlation between specific energy (SE), an indicator parameter of rock cutting efficiency, and three muck size indicators including: coarseness index (CI), mean particle size, and absolute grain size (last one is the correlation with R2 = 0.93). Typically, for the small sized muck with the mean grain size ranging from 3 to 9 mm examined in shale formation in this study, the in situ SE varies between 3.4 and 8.1 kWh/m3. Also, the TBM penetration rate (PRev) follows reasonable trends with respect to other field performance parameters such as boreability index (BI), instantaneous cutting rate (ICR), and machine operational factors including the cutterhead thrust force and torque, in agreement with findings of several similar both laboratory and field scale studies. For example, for the PRev ranging from 5.5 to 10 mm/rev, the BI decreases in power function from 34.8 to 16.8 kN/cutter/mm/rev, and the ICR increases logarithmic from 50 to 85 m3/h. These results highlight the potential development of a real-time monitoring based system can be come on the scene for controlling TBM operation. However, the range of the input data available is very limited, therefore a deep analysis along with an extended database is required for enhancing outcomes of this study.