PURPOSE: To provide construction of lighter embankment by reducing the load on the ground and decreasing the possibility of distortion.

CONSTITUTION: Concrete elements 10a, 10b, 10c capable of being assembled are fixed to each other so as to form a lightweight structure with high resistance, and so as to function as a cell. The elements each can be three- dimensional, of a box-type, or of a shape at a certain angle, or alternatively they may be of two-dimensional plate type. The edges of the respective elements are each provided with a joint. The embankment is completed by lower slabs and upper slabs 36, which are prefabricated or placed in the field, and the elements can be made to cooperate therewith.