PILE FOUNDATION CONSTRUCTION METHOD USING TEMPORARY COFFERDAM CAISSON OF IMPROVED FOR WEAKNESS GROUND

摘要

A pile foundation construction method using a temporary caisson in an improved soft ground is provided to install a submergible structure safely by increasing bearing force of the soft ground, and to cut down construction cost by reducing the construction period. A sand compact pile is constructed in a hole formed in a soft ground(a) by a ground improvement machine, and an improved ground(6) is constructed by a mixture solid pile. The ground is improved around a temporary caisson(10) to install a support bar(13) attached to the temporary caisson. The soft ground is excavated by an excavator, and installed by tare. The support bar attached to the temporary caisson is installed stably in the improved ground by driving a blade edge(10a) of the temporary caisson in an excavation removal ground layer. A worktable is installed in an upper part of the temporary caisson, and a pile foundation(16) is constructed in a support layer(d) by a pile driving apparatus. The sand compact pile is constructed by excavating a bore, supplying sand, putting sand in the bore by a hollow rod, turning and lifting the hollow rod with a rotating unit, feeding sand from a sand injector to the hollow rod and compacting sand from the hollow rod.