Experimental Study on an Ideal Compaction Grouting into Sand

In this study, an ideal compaction grouting technique was designed by injecting grout into a special designed Latex balloon. In this way, the bleeding and penetration of grouts was avoided, and the extension of fractures could be limited. A large scale model test was accordingly developed to investigate the responses of the surrounding soils. After the application of an overburden pressure, pressure grouting was performed on sand samples, meanwhile, the evolution of grouting pressure, soil surface displacement, earth pressure as well as the void ratio at different distance from the injection point are monitored by various transducers. The results show that (i) the pressure grouting induced compaction effect in this study did not reach the up boundary of the model test; (ii) the earth pressure is obvious larger for the soil closer to the injection point; (iii) the densification effect decreases as the distance from the injection point increase, presenting clearly the density gradient around the injection point.