Abstract
A novel stabilizing liquid using an air foam rather than bentonite clay slurry, i.e. an air foam suspension was employed in order to stabilize the trench wall surface during a diaphragm wall excavation. An air foam suspension is created by mixing excavated soil with air foam made from a surfactant. The performance of the air foam suspension depends on its density and consistency, that is, its table flow value (TF). By comparing the trench stabilization capacity of an air foam suspension with that of bentonite clay slurry in model tests, the performance of air foam suspension was confirmed. The performance of air foam suspension for diaphragm wall excavation is presented with two actual trial construction case records, which shows the superiority of air foam suspension to bentonite clay slurry as a stabilizing liquid. This method reduces the wasted soil volume produced from the diaphragm wall excavation and the construction costs of working on an underground diaphragm wall.
