Compression /static pile load testing
Static pile load testing is one of the most common methods for testing the actual in-situ capacity of a pile.
The test program involves the direct measurement of pile head displacement in response to a physically applied load. The test pile is loaded using a calibrated hydraulic jack that applies the test load to the pile by pushing against a beam placed directly over the test pile. The test beam is restrained by an anchorage system consisting of reaction piles installed in the adjacent ground to provide tension resistance. Once the load test frame is in place and fully instrumented, the hydraulic jack applies the test load in a series of increments according to the testing requirements specified by the project’s engineer. Each load is held for a predetermined amount of time until either twice the design load or pile failure is reached, whichever comes first. Pile movement is recorded with each incremental load, and the results are typically presented in a graphical format to the structural engineer of record.
Piles can be tested for compression, tension or lateral loads. By providing actual capacity and deflection values, the test results can be used to confirm that the pile design load can be adequately supported. Depending on the test pile’s performance, the results may also allow for project cost savings by permitting an increase in the pile design load, a reduction in the overall pile length, or a quantification of capacity in difficult or unknown soil conditions. Additionally, the results will offer an improved knowledge of pile-soil behavior, as well as provide valuable data that can be used for future research.