Analysis of seismically‐isolated two‐block systems using a multi–rocking‐body dynamic model

Abstract

A novel multibody rocking model is developed to investigate the dynamic response of two stacked rigid blocks placed on a linear base isolation device. The model is used to investigate the dynamic response of a realistic statue-pedestal system subject to pulse-like ground motions. The analysis shows that, in general, base isolation increases the safety level of the rocking system. However, for large period pulses or small size blocks, the isolator can amplify the ground motion, resulting in a lower minimum overturning acceleration than for the nonisolated system. Further, the amplification or shock spectrum of a linear mass-dashpotspring oscillator, was found to be the reciprocal of the minimum nondimensional overturning acceleration of the investigated rocking system. Novel rocking spectra are obtained by normalizing the frequency of the pulse by the frequency of the isolator. The analysis also demonstrates how the dynamic response of the two stacked blocks is equivalent to that of a single-block configuration coincident with the whole system assumed monolithic or the upper block alone, whichever is more slender.

A Generalized Bouc-Wen Model for Simulating the Quasi-Static and Dynamic Shear Responses of Helical Wire Rope Isolators

“…This can be characterized by symmetric or asymmetric force-displacement hysteresis loops Carboni et al (2018); Antonelli et al (2020); Vaiana et al (2020); Capuano et al (2024a). Furthermore, when nonlinear analyses are required in the design phase to evaluate the effectiveness of these devices, accurate and computationally efficient hysteretic models become essential, especially when the correct design of an isolation system is crucial for the integrity of valuable objects or structural elements behaving like rocking rigid blocks Destro Bisol et al (2023Bisol et al ( , 2024.…”