Effect of Planar Impact Modeling on the Pounding Response of Base-Isolated Buildings

Abstract

During strong earthquake excitations, base-isolated buildings may collide, either with the surrounding moat wall or with adjacent buildings if the available clearance is exceeded. This undesirable possibility has been recently investigated by several researchers, adopting various types of force-based impact models. Evidently, an important issue that arises regarding such numerical studies is the way of taking into account potential impacts. This paper parametrically investigates the effects of impact modeling characteristics on the computed overall peak response of a base-isolated building that experiences structural pounding. Specifically, the Kelvin-Voigt impact model and various other modifications of this linear viscoelastic impact model are considered in the conducted analyses. In order to efficiently conduct this investigation, a specially developed software is used. The results indicate that the excitation's and isolator's characteristics do not significantly influence the variation in the normalized peak response of the superstructure. In contrast, the impact parameters can have a significant effect on the superstructures' peak accelerations with overestimations up to 70%. In general, the normalized peak response ratios of the interstory drifts tend to increase as the available seismic gap and the coefficient of restitution decrease, although the magnitude of the deviations is within 5%, which can be considered insignificant.

Influence of the characteristics of isolation and mitigation devices on the response of single‐degree‐of‐freedom vibro‐impact systems with two‐sided bumpers and gaps via shaking table tests

“…A practical limitation is imposed by this specification on the use of earthquake isolation, because there are often limitations in the amount of clearance available in the presence of seismically isolated buildings, which will later be referred to as gaps, particularly in the practice of adaptation and reinforcement of existing constructions, situated in metropolitan zones. Thus, the danger of impact on the surrounding moat walls or adjacent structures during severe earthquakes and the likely consequences of these undesired events are of great importance …”

“…The main objective of the applicative and theoretical studies is to examine through numerical simulations and also experimentally evaluate the effects of structural pounding at the base‐isolated level in building structures—which are subjected to strong earthquakes—and the resulting dynamic response of the superstructure.…”

“…Base pounding theoretical models with linear spring‐gap element are proposed in Mavronicola et al and Liu et al whereas Komodromos et al Polycarpou and Komodromos, Masroor and Mosqueda, Mavronicola et al and Liu et al formulate nonlinear impact elements that can simulate the contact force during impact of base‐isolated structure to a moat wall; the moat wall was modeled as either a concrete wall with soil backfill or a rigid steel plate and as two‐sided rubber bumpers …”

“…The results for two‐dimensional MDOF models are discussed in Komodromos et al Polycarpou and Komodromos, Masroor and Mosqueda, and Mavronicola et al whereas three‐dimensional finite element analyses are conducted by Liu et al…”

Effect of Ground Motion Directionality on Seismic Response of Base-Isolated Buildings Considering Pounding to Adjacent Structures

“…The majority of those research works simulate the problem in two-dimensions [1][2][3][4][5][6][7][8][9], in an attempt to avoid the complexities associated with the 3D nature of the problem and the consequently excessive computational cost. However, the effect of crucial factors, which may excite the torsional vibration of a building and further increase the possibility of impacts during earthquakes, can be taken into consideration only through 3D simulations.…”