Experimental investigation on backfill grouting deformation characteristics of shield tunnel in sand

Backfill grouting is an important technique to decrease stratum deformation in shield tunnel construction. After backfill grouting completed, grout gradually convert from liquid to solid due to the grout draining and consolidating. Grout volume shrinkage has an important influence on stresses and deformation of soil around tunnel. An element model apparatus was used to test grout deformation under various grout pressures and groundwater pressures. In sand soil, grout deformation time is short; high grout pressure can accelerate drainage and consolidation; high groundwater can slower the grout deformation rate, and minimize the final grout deformation.