ABSTRACT
Chemical grout materials with very low viscosity were developed which could be readily mixed on the surface and injected into the subsoil in ‘one shot’. The mechanical properties of impregnated soils were systematically investigated. Rock with a joint width down to about 0.05 mm and soil in the range of fine sand with silt can be treated with resin. The way to achieve diese goals is limited because the particles of the cement must be able to pass the narrow channels between the pores of the soil. The soil next to the excavation and under the structure was chemically stabilized. Soil stabilization and anchorage guarantee the stability of the existing railway bridge and of the excavation pit for the tunnel. A large number of similar underpinnings have been performed to a high technical standard, that means within short time, at low costs and without settlements of the underpinned structures.
