Sub-Structured Pseudodynamic Testing of Rate-Dependent Bridge Isolation Devices

Despite the continuous evolution of the pseudo-dynamic testing method, the unrealistic testing speed still constitutes a barrier when testing loading rate-sensitive devices. A special procedure accounting for the strain-rate effect of two different types of bridge isolation devices, is presented herein. The procedure consists of a series of simple, sinusoidal-type, characterization tests conducted at different speed, which ultimately yield appropriate force-compensation factors to compensate the, otherwise ignored, strain-rate effect. The procedure is applied to characterize the dynamic response of both, a low-damping elastomeric bearing isolator and a special electro-inductive energy dissipation device. The response of a multi-span, seismically isolated highway bridge is then experimentally studied by sub-structuring, with on-line correction of measured reaction forces to account for the velocity-dependent properties of the isolation devices. The experimental results obtained showed that the procedure can be employed to account for the force modification in testing rate-dependent isolation devices at reduced speed.

PALIOS Xenofon;  MOLINA RUIZ Francisco Javier;  BOUSIAS Stathis;  STREPELIAS Elias;  FARDIS Michael; 

2007-12-19

Tongji University

JRC40314