To shorten excavation releasing length, and reduce risk in which an excavation groove collapses by dividing and executing just under an obstruction at the time of construction of a cost in situ diaphragm wall.
A guide groove for widening excavator is formed in the neighborhood of one side of an underground embedded object, upper excavation is performed by construction of guide material and the widening excavator, and the upper part of one side just under the underground embedded object is widened and excavated. Next, the lower part just under the underground embedded object is widened and excavated, the excavation groove of a prescribed one side part, and cleaning ad removal of slime of the wall face and the bottom part are performed. Next, after a cage is constructed, set at a prescribed position just under the underground embedded object and concrete is placed, the guide groove at the opposite side of the underground embedded object is excavated. Upper excavation by construction of the guide material and the widening excavator is performed, and the upper part of the remaining one side just under the underground embedded object is widened and excavated. The lower excavation and pulling of the guide material by the widening excavator are performed, the excavation groove of the prescribed one side part is formed and the excavator is removed.
MATSUMOTO TSUTOMU
TAKEGAWA MAKOTO
HIRAYAMA TETSUYA
