To provide a method of manufacturing a concrete pit with an integral bottom in which a base structure size is larger than an opening size, with an outer peripheral form and an inner peripheral form by a relatively simple operation in a workshop.

A lower form 1 forming a lid mounting recess portion 2 and an opening 3 is mounted on a platen for operation 9, on which the cylindrical outer peripheral form 4 and the inner peripheral form with a bottom, which has a step forming portion, are erected in a concentric state. A concreting material is poured between the outer peripheral form 4 and the inner peripheral form, after curing only the inner peripheral form is first removed, and the step portion formed on the upper part is filled with a blocking plate 10 comprising a concrete flat plate of the same nature and previously formed separately. Further, the concreting material is poured thereon to form the bottom 11, and after curing, the outer peripheral form is removed, thus finishing all operations.

COPYRIGHT: (C)2007,JPO&INPIT