Effect of Spatial Variability on Disc Cutters Failure During TBM Tunneling in Hard Rock
- PDF / 6,294,703 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 75 Downloads / 190 Views
ORIGINAL PAPER
Effect of Spatial Variability on Disc Cutters Failure During TBM Tunneling in Hard Rock Jin Dalong1,2 · Shen Zhichao1,2 · Yuan Dajun1 Received: 13 November 2019 / Accepted: 1 July 2020 © Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract This study examines the effect of variations of the rock property and TBM parameters on the cutter failure. A new disc cutter wear model is developed by coupling Archard’s model and TBM cutter kinematics. The rock property and the TBM parameters are modelled as anisotropic cross-correlated log-normal random fields. The proposed model with a discretized algorithm allows a quantitative evaluation of the possible cutter failure during the TBM tunneling. The failure of the cutter head system is characterized by a random failure pattern and its failure can be evaluated using a probability method. With this technique, it can be a useful tool in providing an indication for the cutters replacement. Both the cutter and its mechanical system life are determined based on their allowed working distance of the TBM at the targeted safety level. The obtained results indicate that the life of the cutters and its cutter head system decreases with the presence of rock spatial heterogeneity. Finally, the obtained attenuation factors incorporating different randomness levels is practically useful for the evaluation of the cutter life. Keyword TBM tunneling · Hard rock · Disc cutter wear · Spatial variability · Cutter failure · Cutter head system List of Symbols V Volume of wear debris L Relative sliding distance FN Total normal load applied to the material H Vickers hardness of the material K Dimensionless wear coefficient kC Comprehensive wear coefficient 𝜎c Uniaxial compressive strength(UCS) of the rock 𝜎t Tensile strength (TS) of the rock C Dimensionless constant for the cutter-rock interaction 𝜑 Angle of the arc of contact between the cutter and rock S Spacing between two adjacent cutters Rpm Rotation speed of the cutter head r Radius of the cutter T Tip width of the cutter v1 Advance rate of the TBM * Shen Zhichao [email protected] 1
School of Civil Engineering, Beijing Jiaotong University, Beijing, China
Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
2
ds Diameter of wear flat in the Cerchar test c Unit correction factor in the Cerchar test Fc Normal force used in the Cerchar test sc Test distance in the Cerchar test v2 Rotation speed around the cutter’s axis v3 Rotation speed around the tunnel axis tp Duration of the interaction for each revolution of the cutter R Installed radius of the cutter at the cutter head 𝜃 Angle between the calculation point and bottom point of the cutter w0 Angular velocity of the cutter around its axis lp Relative sliding distance for one revolution of the cutter Ls Length of the element in the model l Relative sliding distance in the element length Ls 𝛿V Cutter wear in the element length Ls ICA Cerchar abrasivity index u Mean value of
Data Loading...
