The Use of Rapid Load Test as Alternative Load Test Method of Bored Piles

Rapid load test (RLT) is becoming common in Singapore as a higher productive, lesser labor-intensive pile load test method alternative to conventional static test method, such as by Kentledge, for assessing the axial static behavior of piles. RLT has a longer loading duration in comparing with high strain dynamic (PDA) test, resulting in pile response closer to static behavior and simplifying the interpretation procedure. This paper presents the experiences of RLT on cast in-situ bored piles in Singapore adopted as the alternative test method for ultimate load test and working load test. The RLT test results are compared with conventional static test results on similar or equivalent pile. From the presented data, the load displacement responses of RLT were practically identical to the response of conventional static test, though the data has shown that correction factor should be established through site-specific calibration tests for pile head settlement > 3% of pile diameter. Unit shaft resistance and unit end bearing mobilized in RLT, and equivalent static tests were compared and were virtually matching.