Prediction and analysis of replaceable scraper wear of slurry shield TBM in dense sandy ground: A case study of Sutong GIL Yangtze River Crossing Cable Tunnel

Prediction and analysis of cutting tool wear in dense sandy ground is important for improving the working performance of slurry shield TBM, especially for long-distance cross-river tunnel. Appropriate prognosis model can not only improve the construction efficiency, but also avoid the risk from cutterhead inspection and tool maintenance which are difficult, time-consuming but necessary procedures. Although several prognosis models have been utilized for estimating cutting tool wear, these models have inherent mismatches with actual geological conditions of tunnel projects. In order to promote the predictability of cutterhead inspection and tool maintenance, empirical prognosis model suggested by the Japanese Society of Civil Engineers (JSCE) has been improved by proposing a new method for the calculation of the wear coefficient in heterogeneous ground. Compared with initial model, the improved model takes into account the influence of stratigraphic change along the tunnel alignment on the wear coefficient. Hence, it is more applicable and accurate. A case study on the prediction and analysis of replaceable scraper wear in dense sandy ground at Sutong GIL Yangtze River Crossing Cable Tunnel has been carried out by using the improved model. The predicted value is comparable with the actual value in terms of wear coefficient and wear extent.