Abstract
The RS method is a new pile driving method that is well suited to the construction of foundations in port areas. In such areas, oftentimes an impact hammer cannot be used because the noise and ground vibration caused by the hammer are problematic for neighboring industrial plants and residential areas. However, the bearing capacity of piles driven by vibratory pile driving with water jetting or cement milk jetting is uncertain, although these methods can decrease the noise and ground vibration compared to the impact hammer. The RS method drives the pile using a vibratory hammer with water jetting and forms a soil cement block on the tip with cement milk jetting. In this paper, we show the bearing performance by analyzing the axial loading for 600 ~ 1300mm diameter piles driven by the RS method. It was found that the bearing capacity of the test piles was determined by the soil resistance, and the strength of the soil cement block, which was estimated by an unconfined compression test, is much higher. This result indicates that the soil cement block is well-constructed, and if a pile is driven into soil that is harder than the soil used in the test, it is possible the pile will even have higher bearing capacity. Furthermore, the feature of the resistance mechanism of piles driven by the RS method is believed to be the high shaft resistance in the soil cement block.
