Abstract: Deformation and mechanical properties of backfill grouting material directly affect soil stress release, ground subsidence and late stress situation of segment lining. Based on triaxial test method of non-independent material, we take the rigid slurry and inert slurry as research objects, carrying out consolidated non-drained triaxial shear test. Results show that, 1) high confining pressure contributes to the consolidation and drainage of the slurry, and the ultimate volumetric strain of the slurry increase with confining pressure; 2) in the shearing process on the non-drained condition, slurry shows tendency of strain hardening, and the volume shrinks first, then with obvious shear dilatation. On the premise of deformation and construction requirements, we can suitably increase grouting pressure and use slurry with smaller water-glue ratio to ensure the construction quality of grouting body.

Key words: shield, backfill grouting, triaxial test, shear stress, pore pressure dissipation, volume strain