Numerical study on the TBM mucking performance in EH project and optimization of the supporting ribs

Anotace: To study the cutterhead’s muck transfer performance of the TBM applied in EH project, China, a discrete element method (DEM) based numerical model was built and the mucking process was simulated at different penetration rates and cutterhead rotational speed. It is found that the conventional straight-supporting-rib cutterhead performed well at different penetration rates and low RPMs, but the muck excessive-thrown problem was serious when the RPM was higher than 10 rev/min. To overcome this problem, a new arched-supporting-rib cutterhead was proposed. The curvature radius of the arched supporting ribs is suggested between 1.25 m and 1.75 m, and the offset angle is suggested between 40° and 45°. The newly proposed arched-supporting-rib cutterhead can performed well in muck transfer at a greater RPM range of 4~13 rev/min, which allow the TBM to excavated at low, medium and high RPMs considering ground conditions and requirement of construction progress.