The shield machine has the characteristics of fast tunneling speed, safety and efficiency, and is widely used in the construction of urban underground space. As an important part of the broken rock mass on the shield machine cutter head, the disc hob directly cuts and breaks the rock mass during the excavation process, so the wear of the hob is the most common and unavoidable difficult problem in the shield machine excavation construction. Based on the feedback information of tool wear during the excavation construction of Shenzhen Urban Rail Transit Line 13, this paper first classifies and counts the wear forms of the shield machine disc hob, and then analyzes the causes of different wear types of the disc hob. mechanism. Based on the slip line theory, a prediction model for the normal wear of the disc hob was constructed, and the correctness and applicability of the prediction model were verified by the on-site wear data. Finally, the normal wear and abnormal wear of the hob were successfully reduced by means of tool shape parameter optimization, tunneling parameter optimization and hob reinforcement optimization, and good field benefits were achieved.

slip line theory ; rock breaking by hob; wear characteristics; uniform wear; prediction model; case validation