Application of colloidal silica grout to stabilize against liquefaction the foundation soil of an existing school building

Chemical grout using a colloidal solution of sodium silicate has been selected to stabilize against liquefaction the foundation soil of a school building located in the town of Cesenatico, Italy. The building is located only few hundred meters from the shore line. The subsoil consists of about 8.5 m of sand and silty sand followed by a 15 m thick layer of silty clay. The ground water table is located at a depth of 1.5 m from the ground surface. In this paper the results of laboratory tests carried out to verify the efficacy of the colloidal solution in increasing the soil resistance against liquefaction are presented.