Online monitoring and analysis of TBM cutter temperature: A case study in China.

• TBM cutters temperature monitoring system was applied to a real in-site. • The effect of installation radius and penetration on cutter temperature was studied. • Sludge fluidity was presented by PTR (ratio of penetration to screw conveyor speed). • PTR is proposed and used to analyze the trend of relative temperature change. Excessive cutter temperature during TBM tunnelling may cause severe cutter wear, mud cake formation, or even blockage of the cutterhead. It will increase construction costs and safety risks. Therefore, in this study, based on the PT100 temperature sensor and wireless transmission technology, a set of cutter temperature online monitoring system has been developed and applied to an TBM construction in-site. Statistical analysis of the in-site temperature data shows that: (1) During excavation, the cutter temperature range was about 13–25 ℃. (2) When penetration is less than 32.4 mm/r, the relative temperature change (ΔT) will increase as the installation radius increases. On the contrary, as the installation radius increases, the ΔT decreases first, then increases. (3) The ΔT is affected by the flow velocity of sludge (PTR). When PTR decreases, if the heat lost by the sludge is higher than the heat generated by the penetration, the ΔT will decrease. [ABSTRACT FROM AUTHOR]