The present invention relates to an automatic level-control floating apparatus, which supports a superstructure and constantly controls the level (vertical position) of the supported superstructure. The superstructure may be a pontoon bridge or a floor that floats on the sea.
In order to eliminate the need to adjust the level of a known pontoon bridge, which may vary in level, a long movable ramp is provided between the bridge and the land. Because the ramp slopes as the pontoon bridge varies in level, it cannot be used where it needs to be horizontal.
The pontoon of another known pontoon bridge is fitted with ballast pumps for pumping water into and from the pontoon to adjust the level of the bridge. For example, reference may be made to Japanese Unexamined Patent Publication No. H11-172620 (paragraph 0009, FIG. 1). Because the ballast pumps need to keep operating, the pontoon bridge requires high running costs for the operation, maintenance, etc. of the pumps.
In general, the foundations of the piers of bridges constructed on the sea etc. need to be laid on firm ground. If the foundations are laid on very soft ground, or if they are very deep in water, the construction costs of the bridges are very high.