PURPOSE: To use the upper space of river, beach, mountain, cultivated land, or the like, and construct an airport, by arranging floor boards which are divided and are continuously set and are adjustable two-dimensionally and telescopically, on struts, and by arranging a buffer and an oscillation-proof device.

CONSTITUTION: On ground, struts 1 are erected, and on the struts, longitudinal beams 6 are arranged on longitudinal upper sections, and width-directional beams 7 in the same shapes are arranged on width-directional lower sections, and both the beams are fitted firmly and integrally to form floor boards 5. Between the struts 1 and the floor boards 5, via lower fixed boards 2 and upper fixed boards 4 fitted on the respective ones, elastic objects 3 are arranged to set an oscillation-proof device. On the upper surfaces of the longitudinal beams 6, shape steel plates 10 on the whole surfaces of the floor boards 5 are jointed, and on the plates 10, paved 12 path floors 11 are formed.