Efficiency analysis of hydraulic Junttan pile driving hammer

The main results of hydraulic hammer study held in Hong Kong in 1994 are presented. The tests included stress wave measurements of four different hydraulic hammers and one open ended diesel hammer at three different sites by using two different types of piles. Stress wave measurements were analyzed by CAPWAP-program and static load tests were performed. All hydraulic hammers were provided by manufacturers’ own kinetic energy measurement equipment which enables the determination of driving system efficiencies. According to measurements the hydraulic hammers were much more efficient than the dieselhammer. In addition differences between various hydraulic hammers can be found. Stress wave measurements for Junttan HHK-9A-hammers were further analyzed with GRLWEAP-program and by using an analytical approach. A simple dynamic piling formula is suggested from the results.