CONSTRUCTION METHOD FOR FIXING HOLLOW COLUMN FOR SUPPORTING MARINE STURCTURES AND OFFSHORE PLATFORMS TO A SEABED

摘要

A construction method for fixing a foundation of a waterborne structure including an offshore platform to a seabed (2) is described. The foundation includes at least one hollow column (108) which incorporates a pile cap (43) at its bottom. In the method, piles (49) are driven into the seabed (2) to a design depth, and the hollow column (108) is then lowered to the seabed (2) so as to surround the pile group and be supported thereby. Concrete is cast into the bottom of the hollow column (108), wherein reinforcement steel bar(45) has been pre-installed to translate the conventional mass concrete plug into a reinforced concrete small pile cap (43) adapted to support the hollow column (108) thereon during construction. The hollow column (108) is de-watered, excessive pile length is cut, and pile cap reinforcement (47) is fixed followed by concrete casting of the pile cap (44). A platform deck is then installed and constructed on top of the now-fixed hollow column (108).