APPARATUS FOR A LOADING TEST OF A PILE USING A SELF-REPULSIVE PORCE

摘要

The pile load tester for finding the ground condition for a building construction has a pile shoe (2) and a core (30) on the bottom end of a pile frame (1) having on its inner side a catch ring projection (4), the pile shoe (2) having on its top an oil jack (8) equipped with an auxiliary oil jack (8a) for actuating the core (30) and also having a lock member (9) for being caught by the ring projection (4). The operation of the jack moves upward the lock member to be caught by the ring projection and further move the pile frame upward and push the pile shoe downward. The gradual increase of the jack oil pressure makes the pile frame in movement to break the resistance of the surrounding earth and bring a sudden rapid movement whose upper travel distance is measured. At the same time, the oil pressure is determined to be the maximum friction force of the surrounding. Then the auxiliary jack is operated to increase the pressure until the core makes a sudden rapid down movement. The pressure at this time is determined to be the maximum tip resistance.