This paper describes the field measurements with a vibration exciter to examine the vibration reduction effect of PC Wall-Piles. Three dimensional simulation results are also presented to clarify the basic characteristics of vibration reduction. A PC Wall-Pile, which is widely used for retaining walls, has a hollow part in the square section in order to excavate the natural ground. This wall has an advantage to be made safely adjacent to the important structures, such as a Shinkansen viaduct, because it can prevent loosening the nearby ground. In the field test and the simulation, special attention is devoted to the influence of hollow size on the vibration reduction effect, so that the hollow size varies in three steps from maximum (620 mm of inner hollow diameter) to zero. From the field results, it becomes clear that 1) Apparent vibration reduction effect shows when the wall depth is over approximately one wave length of surface wave, and that 2) Vibration reduction effect of hollow size seems complex, because the pile weight and stiffness may have an impact as well as the hollow size. Then the 3-D numerical simulation is conducted to discuss the field results. It becomes clear that 1) Numerical model of this study is a powerful tool to discuss the vibration effect of the PC Wall-Piles, and that 2) According to the simulation results, PC Wall-Piles with larger hollow has an vibration reduction effect especially in higher frequencies, such as 15 to 25 Hz.
