Pile Test Services
A bi-directional static load test (BDSLT) is a method used to internally load a deep foundation element from specific points along its embedded length. The load is applied using a jack assembly, which includes one or more YJACK360 or OJACK360 cells positioned between upper and lower bearing plates. This setup allows the jack to exert an upward force against the shaft resistance above the jack assembly and a downward force against the combined shaft resistance below the assembly and the toe or base resistance. The deep foundation element is equipped with instruments to measure shaft and toe movements, as well as soil resistance to the applied load. YJACK360 and OJACK360 cells are suitable for installation in drilled shafts, augercast piles, drilled displacement piles, slurry wall panels, and barrettes.
| Aspect | Description |
|---|---|
| Test Name | Bi-Directional Pile Load Test |
| Test Purpose | To assess the bearing capacity and settlement of a pile by applying load in both upward and downward directions from within the pile. |
| Test Standard | ASTM D8169/D8169M-22 |
| Test Procedure | Load is applied internally at a specified level within the pile, with measurements taken for the resulting movements at the pile head and toe. |
| Load Application | Load is applied using hydraulic jacks placed at a pre-determined depth within the pile. |
| Test Measurement | Displacement is measured at the pile head and toe to determine load distribution and ultimate capacity. |
| Key Parameters | Load vs. displacement, load distribution, and pile shaft resistance. |
| Test Duration | Depending on project requirements, from 7 hours to 7 days. |
| Load Application | Mainly 2 cycles to be tested. |
| Test Applications | Commonly used for deep foundation verification in high-rise buildings, bridges, and infrastructure projects. |
| Test Advantages | Allows for higher loads to be tested with less reaction mass, reducing overall costs and setup time. |
| Test Limitations | equires pre-installation of loading jacks within the pile, which may limit application in some scenarios. |