Model of compaction grouting

Compaction grouting is an important soil improvement and underpinning technique that involves injection of a very stiff grout material into the soil. The objective is to displace and compact the surrounding soil without permeating or hydrofracturing it. Compaction grouting has been developed and used almost entirely on the basis of practical experience. The present study proposes a theoretical model that describes the mechanics of the compaction grouting process and rationally considers the different soil and grouting parameters that govern the overall design and performance of the method. The theoretical basis of the model draws from the theory of cavity expansion as well as the conical shear failure above the grout bulb. This model was validated using limited available data. The results indicate reasonable agreement and show a good potential of the proposed model for rationally optimizing the design of compaction grouting operations.