Wear Characteristics of Disc Cutter and a Method for Disc Cutter Life Improvement

摘要

In order to improve disc cutter life on TBMs, a series of studies, which consisted of investigation on wear characteristics of disc cutters in situ, construction of a wear model for disc cutters and suggestion of a method for disc cutter life improvement, were conducted.From the examination and analysis of disc cutter wear on TBMs in two tunneling sites. it was shown that disc cutter life is dependent on its position (cutting radius) on the cutter head. Rolling distance per unit wear of disc cutters near the center of the cutter head is extremely shorter than ones in the other positions. The edge shape of a worn cutter is also dependent on its position.These characteristics can be explained well by the model based on skid between a disc cutter and rock. In cutters near the center of a cutter head, the life is much shorter and the wear on the outside face of the disc is outstanding because lateral skid is much predominant.As a method to decrease the wear induced by skid, the offset arrangement of disc cutters was suggested and the equation for the optimum offset condition was derived. It was calculated that the cutter life might be elongated up to twice by the optimum offset arrangement.