大規模発破震動を用いた液状化地盤における杭支持構造物の振動実験 : 実験方法と地盤-杭基礎-構造物の応答性状

Abstract

Vibration tests of a pile-supported structure in a liquefiable sand deposit have been conducted at a large-scale mining site. A simple pile-supported structure was constructed in an excavated 3m-deep pit that was backfilled with saturated sands. Ground motions from large-scale blasting operations were used as excitation forces for vibration tests. Accelerations were measured at the pile-supported structure, in the test pit and in an adjacent free field. Excess pore water pressures in the test pit and pile stresses were also measured. As the level of the input motions increased, structure responses and pile bending moments were remarkably changed by pore water pressure buildup. It is thus clarified that this vibration test method was very effective to verify the soil non-linearity including the liquefaction and the dynamic behavior of the pile-supported structure.