Strength Improvement of Loose Sandy Soils Through Cement Grouting

Grouting, which has several applications in the field of civil engineering, was once considered as a mysterious operation. The effectiveness of grouting requires a lot of understanding, skill, meticulous attention and an intuitive perception. Even though grouting was started 200 years ago, it was treated for a long time, as an art which eluded scientific investigation and improvement. Grout is injected under pressure into the material to be grouted until it fills the desired volume of material around the hole or until the maximum specified pressure is attained and a specific minimum grout flow is reached. This paper discusses the strength improvement of loose sandy soils through cement grouting. Various cement percentages (2, 4 and 6 %) were used for grouting medium sand beds in the loosest state. The effectiveness of grouting was evaluated based on the actual cross sectional area of the intact grouted mass at different depths and by determination of cement content at various depths and laterals distances of the grouted medium. The improvement in strength due to grouting was assessed with the help of load tests. 4 % cement grout was found to be more effective in medium sand compared to 2 and 6 %. The results undoubtedly prove the effectiveness of using grouting as an efficient technique in improving the foundation beds of loose sandy soils.