Skip to main content


Port slab
Monfalcone, Italy
Duration / Year
2 days / 2011

Slab lift


The area of the shipyard affected was formed by a range of industrial flooring in reinforced concrete, located between the yard and the rail of the crane in the ship assembly area. The sinking of the foundation soil occurred because of the passage of the crane that operates carrying heavy loads in the shipyard. The deformation of the strip along the cable channel presented irregular and distributed depressions. The maximum sinking observed came to about 60 mm. The ground below the cable-channel curb is of granular nature, mixed with clay, and deposited to the left of the support structure of the crane, which was made many years ago. At the last works of the yard in 2008/9, besides compacting amounts underneath, and projecting 40 cm of the floor thickness, it was not possible to compact the soil of the already existing adjacent strip.


The objective was to compact the soil beneath the concrete slab and lift the floor to the desired level. 


To eliminate the problem at its root, URETEK was chosen for its great experience and professionalism with Geopolymer Injections patented technologies. Drillings with less than 3 cm of diameter were made through the concrete curb and extended to some points to a maximum length of 2.0 m through its thickness, spaced at regular distances; working from the top and centrally to the curb of the channel. The injections were performed in levels closer to the surface and in deeper ones from the bearing surface of the curb. This way it achieved and consolidated accurately all of the so-called “significant” volume; also, the desired concrete slab lifting was performed.


The Geopolymer injections of quick expansion and high swelling pressure thickened the deep soil throughout the area surrounding the injection point; that way, the contact between the substrate and the curb in reinforced concrete was completely restored. The Geopolymers, by swelling, produced the densification of all the soil surrounding the injection and expanded vertically to relevel the floor. The success of the intervention was checked through pre-injection and post-injection tests, allowing us to appreciate the increase in mechanical parameters of the volumes of soil treated. The vertical lifting of the concrete component is an indication of the effectiveness of the treatment. The intervention required 2 working days and comprised 3 different transiting areas of the crane for a total of about 80 linear meters of curb restored.