ABSTRACT
In Japan, most pile foundations using pre-cast concrete piles are installed by the bored pre-cast piling method, wherein pre-cast piles are inserted in holes that have been excavated beforehand and filled with cement milk (term used for cement water slurry in Japan). The bored pre-cast piling method with enlarged base, in which a portion near the toe is enlarged during boring operation, is widely used because of the cost benefits owing to the increased vertical bearing capacity that this method offers. Conventionally, the diameter of the grouted base was enlarged to 1.1 to 1.15 times.
