A Mesoscopic Viewpoint on Slurry Penetration and Pressure Transfer Mechanisms for Slurry Shield Tunneling

The penetration characteristics of the slurry and support pressure transfer mechanisms are critical to tunnel face stability control during a mechanized excavation. In this paper, numerical calculations coupling computational fluid dynamics (CFD) with discrete element method (DEM) carried out simulate sand column tests considering different particle size ratios. reasonableness model is verified by comparing variation patterns soil permeability coefficients monitored in results existing laboratory tests. mesoscopic transport particles pores considered based on tests, while effects corresponding types evaluated. Three main basic infiltration observed due ratios over pore size. For first type, accumulated able form supporting filter cake. effective because significant drop generated both sides second cake an zone present. A dense filling network formed between zone. third type corresponds purely An impermeable cannot be formed, effect not obvious. development distance shows obvious time effect; farther distance, larger filtration loss, worse transformation pressure.