基于EDEM及Archard接触模型的砂卵石地层盾构刀具磨损特征研究

In order to reveal the wear characteristics of typical EPB shield cutters in sand–pebble stratum and guide the design and layout of shield cutters in this stratum, the contact parameters of sand–pebble soil were calibrated through indoor triaxial shear test and numerical simulation results of EDEM, and the 3D discrete element numerical tunneling model of shield in sand–pebble stratum was constructed. Based on the Archard Wear contact model, the wear characteristics of typical rippers and scrapers in soil pressure balance shield tunneling in sand–pebble stratum were visualized, and engineering verification was carried out through an example of cutting tool wear in the shield tunneling section of the Beijing New Airport Line 06 section from Cigezhuang Station to NO.1 air shaft. Research has shown that: 1) The rippers aimed at plowing loose the undisturbed soil are the essential cutting tools with an excessive wear, and the manifestation is continuous friction and wear on the alloy surface of the cutting head and at the blade edge. 2) The scraper for the purpose of stripping and discharging is protected by the ripper on the same trajectory radius, and the wear is relatively small, mainly manifested by random pitting wear on the soil facing surface of the cutter body and the alloy surface of the cutter head; 3) The wear of radial cutters on the cutterhead gradually increases, and high cutters on the same trajectory have a protective effect on the wear of low cutters. The gradient arrangement of cutters can extend the single continuous excavation distance and improve the efficiency of shield tunneling in sand–pebble stratum.