Technical Papers : Case Study of Load Capacities for Bi-Directional Pile load Tests

Since the applying load is usually set improperly in bi-directional loads on large diameter piles, confusion often emerges when a bi-directional pile load test is performed. In this research, test load increasing ratios, and sufficiency ratios of design load were analyzed based on 96 of bi-directional pile load tests. Based on the analysis, the maximum equivalent test load, which produced by adding the bi-directional loads at equal movements, did not reach as much as the bi-directional accumulated load. Also, the design load can be verified only if the upward or downward test load is more than twice of it. Therefore, as conservative, the loading capacity had better increase as twice of the maximum upward or downward loading capacity to verify the design load.