Comparison of static load test and rapid load test on steel pipe piles in two sites

Two case studies of comparison of the static load test (SLT) and the rapid load test (RLT) on steel pipe piles (SPPs)
are presented and discussed in this paper. The Hybridnamic device, a falling-mass type RLT device, was used in both
two cases. In Case study 1, an SPP having an outer diameter of 800 mm and a length of 23.8 m was installed in a
weathered rock ground using the down-the-hole hammer method (a percussion drilling method). In the RLTs, three
accelerometers were attached to the pile at head, intermediate and tip levels. Unloading Point (ULP) Method was used
to interpret the RLT signals. Static load-displacement curves derived from the RLTs using three different accelerations
are compared with those from SLTs with the step load method and the continuous load method. An appropriate
selection of  is discussed, based on the measured results. In Case study 2, an SPP having an outer diameter of 1000
mm and a length of 15.5 m was installed in a sandstone having SPT N-values greater than 50 using a vibro-hammer
together with water jetting. Acceleration at the pile head alone was measured in the RLT. Static load-displacement
curve derived from the RLT with ULP was comparable with that obtained from the SLT.