The hammer pile driving method is popular for installing steel pipe piles in port and harbor areas. It is getting harder to apply this method, because of noise and vibration problems. Vibro hammer method with water jetting, so-called ‘JV Method’ has been effectively used instead of using hammer pile driving method to avoid the noise and the vibration problems. The bearing capacity of steel pipe piles installed by JV Method is not so high as that of installed by hammerpile driving method, because water jetting tend to disarrange supporting layer. Therefore it is required to develop new pile driving method such as to perform high bearing capacity with low noise and low vibration when installing piles. This method is called 'RS plus method.'
　This method is an improvement method of the JV Method. When penetrating piles into ground, water jetting and vibration hammer are used to reduce noise and vibration. And assured soil cement block is constructed at around pile tip with　cement milk. In thismethod, noise and vibration will be decreased when installing piles, and high bearing capacity of piles will be performed.
　Model pile load experiments to confirm axial resistance, water jetting model experiments to confirm the washing performance around and inside of the pile tip were conducted in the laboratory. Then, full-scale pipe pile construction works for checking the shape and quality of the soil cement treated zone around the pile tip were conducted to certify the jetting systems. Finally, installation and static loading tests were conducted to the full-scale piles installed into about 20m depth.
　From these research works, design method and installation procedure of 'RS plus' were proposed.