FLAT JACK USING HIGH PRESSURE PIPE

摘要

The present invention relates to a flat jack inserted into a crack gap formed artificially to measure displacement of a crack from a pressure by applying pressure to a crack surface in order to find the size of remaining pre-stress in a concrete structure, more specifically, to a flat jack using a high pressure hose which is improved so as to act on the crack surface uniformly without any loss of pressure. The present invention provides: a plurality of high pressure expanded cylinder assembly (2) having a tube body; a distributor (3) which is combined with the top of the high pressure expanded cylinder assembly (2) and distributes the pressure injected through a hydraulic injecting hole (31) to each high pressure expanded cylinder assembly (2).