Seismic control of rocking structures via external resonators

Abstract

Summary Tall rigid blocks are prevalent in ancient historical constructions. Such structures are prone to rocking behaviour under strong ground motion, which is recognizably challenging to predict and mitigate. Our study is motivated by the need to provide innovative nonintrusive solutions to attenuate the rocking response of historical buildings and monuments. In this paper, we examine a novel scheme that employs external resonators buried next to the rocking structure as a means to control its seismic response. The strategy capitalizes on the vibration absorbing potential of the structure‐soil‐resonator interaction. Furthermore, the benefits of combining the resonators with inerters in order to reduce their gravitational mass without hampering their motion‐control capabilities are also explored. Advanced numerical analyses of discrete models under coherent acceleration pulses with rocking bodies of different slenderness ratios under various ground motion intensities highlight the significant vibration absorbing qualities of the external resonating system. The influence of key system parameters such as the mass, stiffness, and damping of the resonator and those of the soil‐structure‐resonator arrangement are studied. Finally, a case study on the evaluation of the response of rocking structures with external resonators under real pulse‐like ground‐motion records confirms the important reductions in peak seismic rotational demands obtained with the proposed arrangement.

Impact and clutch nonlinearities in the seismic response of inerto-rocking systems

“…The proneness of rocking structures to large deformations and rotations together with the increased accelerations caused by impact and uplifted resonance have motivated researchers to look for suitable seismic vibration control strategies. While some have attempted to reduce the seismic vulnerability of rocking structures by preventing uplift (Makris and Zhang 2001), others have proposed a range of passive and semi-active control strategies (Ceravolo et al 2016;Dimitrakopoulos and DeJong 2012;deLeo et al 2016;Vassiliou and Makris 2012;Pan and Málaga-Chuquitaype 2020) A promising seismic control strategy, recently investigated by Thiers-Moggia and Málaga-Chuquitaype (2019, 2020a), consists in the use of inerters. These devices, initially studied in Japan by Arakaki et al (1999) and popularized in the West by Smith (2002), are two-node mechanical devices that develop resisting forces proportional to the relative acceleration between their terminals.…”

Exploring the performances of the vibrating barriers for the seismic protection of the Zoser pyramid

“…Due to the large masses involved in the traditional ViBa device Cacciola et al 23 developed an inerter-equipped Vibrating Barrier showing that is possible to reduce the mass of the vibrating unit at least by 50% achieving the same level of performance. Pan and Málaga-Chuquitaype 24 extended this approach to the control of rocking structures using combined inerters and external resonators.…”

Performance-based seismic design and assessment of rocking timber buildings equipped with inerters

“…The main advantages of these configurations included an improved reduction of peak deformations and a wider suppression band. The mass-amplification effect of the inerter has also been harnessed to improve the performance of vibration barriers [44,45] and to reduce the displacement demands of base isolation systems [46][47][48][49]. Importantly, all these previous studies have focused on the seismic control of fixed-based structures.…”