Nonlinear Response and Damage Monitoring of a Concrete Pile as a Result of Soil Liquefaction

Abstract

In past earthquake disasters, numerous building structure piles were damaged due to soil liquefaction occurring during the earthquake. Damage to these piles, because they are underground, is difficult to find. The authors aim to develop a monitoring method for pile damage based on superstructure dynamic response. This paper investigated the basic relationship between the damage of large cross section cementitious piles and the dynamic response of the super structure using a centrifuge test apparatus. A dynamically excited specimen used simple cross section pile models consisting of aluminum rod and mortar, saturated soil (Toyoura sand) of a relative density of 40% and a super-structure model of a natural period of 0.63 s. In the shaking table test under a 50G field, excitation was a total of 3 Rinkai waves at different amplitudes. The maximum acceleration of each of the excitations was 602, 336 and 299 gal. The centrifuge test demonstrated the liquefaction of saturated soil and the failure behavior of piles. In the test results, the damage to the piles affected the predominant period of acceleration response spectrum on the footing of the superstructure.