MODEL EXPERIMENT ON THE CONSTRUCTING PROCESS OF SOIL CEMENT BLOCK WHICH WAS POSITIONED ON THE TIP OF THE PILE DRIVEN BY VIVRATORY PILE DRIVING WITH WATER JETTING

It has been shown already that the pile driven by the vibratory pile driving with water jetting and constructed soil cement block on the tip can reduce sound and ground vibration, and perform high bearing capacity. However, the construction process of the soil cement block on the pile tip hasn't been relieved. Because of this situation, the authors have tried to clarify the mechanism of that by the centrifuge model test and model tank test. As a result, it is shown that the length which water jet excavates can be analyzed quantitatively by the previous research about jet grouting. And, in the case of multiple water jet, it is presumed that the soil strength of the gap between the excavation area decrease and the excavation progresses more efficiently. Finally, the authors have made a design about the suitable specification for the large diameter pipe pile, and confirmed that this can construct the soil cement block for the large diameter pipe pile by the model field test.