PURPOSE: To save the labors, by arranging a blade freely advancing or retracting toward the periphery of a truck frame, on the upper face of the lower carrier body frame to reject the soil piled on the upper face of the lower carrier frame by the blade.

CONSTITUTION: When rejecting the piled soil, the blade support 61 is lowered and fixed by bolts 26. Then, the upper gyratory body is rotated to turn the soil-removing plate 60 and reject the piled soil within the range A in which the soil does not collide with various parts on the upper face of the lower carrier body 1. When the blade 6 is not used, after the soil-removing plate 60 has been rotated reversely, the support 61 is raised and fixed by the bolts 26. In this location, the soil-removing plate 60 is positioned between the lower face of the swing frame 20 and the upper face of the upper part of the truck 14, so that the blade 6 is kept not to hinder it at the rotary movement of the upper gyratory body or the transferring movement thereof. In this way, labour for removing soil can be remarkably saved.