TBM Cutting Tools Maintenance Technology for the Yellow River Crossing Project in the Middle Route of South-to-North Water Diversion Project

The geological conditions of the Yellow River Crossing Project in the Middle Route of South-to-North Water Diversion Project are complicated,for the crossing tunnel strata consists of total sandy layer,total earth layer,upper sand and lower earth layers mixed.In the design of cutter head for shielding machine,soft soil cutting tool and heavy-load cutter head force-transmitting frame were applied to protect the cutting tools.However,during the TBM construction,the facts of abnormal excavating parameters and mucking containing metalwork demonstrated that the TBM cutting tools were severely wearing.By chamber-entering check under pressure,we found out problems and replaced some damaged cutting tools.After the foundation reinforcement,we made a thorough rehabilitation on the cutters needed to be repaired by the scheme of chamber-entering under normal pressure.This maintenance experience can provide an important guide for smooth progress of the Yellow River Crossing project,and a reference for similar projects.