Displacement Infiltration Diffusion Model of Binghamian Grouts as Backfill Grouting of Shield Tunnel

Abstract:

With Bingham grout as the study object, this paper deduces the spherical displacement infiltration diffusion model by applying generalized Darcy's law and theories of seepage mechanics based on the displacement effect of grout for groundwater. Through examples, the characteristics of the grout infiltration diffusion when considering the grout displacement effect is analyzed, and the main factors affecting the grout infiltration diffusion is analyzed. The results show that when the grout displacement effect is considered, the grout pressure in the diffusion front decreases along the concave curve with the increase of the diffusion distance. Although the change of frontal grout pressure is small, it has a great influence on the grout diffusion radius, and the grout diffusion distance shortens about 23% at 1 h.

Key words:shield tunnel; backfill grouting; infiltration; displacement effect