Seismic demands on nonstructural components anchored to concrete accounting for structure‐fastener‐nonstructural interaction (SFNI)

Abstract

This paper investigates the influence of the hysteretic shear behavior of postinstalled anchors in concrete on the seismic response of nonstructural components (NSCs) using numerical methods. The purpose of the investigation is to evaluate current design requirements for NSC and their anchorage. Current design guidelines and simplified methods, such as floor response spectra (FRS), typically approach the dynamics of the structure-fastener-NSC (SFN) system using simplified empirical formulae. These formulations decouple the structure from the NSC and neglect the behavior of the anchor connection, with the assumption of full rigidity. There is a lack of knowledge on the complex interaction between a host structure, the fastening system, and the NSC, herein referred to as structure-fastener-nonstructural interaction (SFNI). More specifically, it is important to investigate whether and how the actual hysteresis shear behavior that takes place in the anchorage could alter the seismic response of the SFN system and its components. Herein, the results of extensive nonlinear dynamic analyses (NLDA) with different models for the anchorage force-displacement relationship are presented and compared with those obtained with FRS procedures and current code provisions. The anchor models include (a) linear-elastic, (b) bilinear, and (c) a recently developed hysteresis rule. The results of the NLDA showed that the first two approaches are not able to reflect the behavior of an anchor loaded in dynamic shear. Moreover, when using the more refined hysteresis model, it appears that current code provisions might underestimate the component and anchor shear amplification factors for rigid NSC fixed to the host structure through anchors. K E Y W O R D Sanchorage shear hysteresis, macro modeling, nonstructural components (NSCs), postinstalled fasteners in concrete, structure-fastener-nonstructural interaction (SFNI)

Shake table tests of concrete anchors for non-structural components including innovative and alternative anchorage detailing

“…damping sources provided to the NSCs, which might well be of the order of 5%. Following this approach, when a fully rigid anchorage and NSC is considered (T NSC = 0), the acceleration demand on the NSCs is usually underestimated as shown in Pürgstaller (2017), andPürgstaller et al (2020). Thus, when the non-linear hysteresis behaviour of the anchorage is explicitly accounted, the acceleration levels predicted for the NSC are much larger than those obtained with the simplified (typically code-based) elastic methodology which can thus be unconservative.…”

“…In such a context, and as part of an academic-industry research partnership between Sapienza University of Rome, the University of Natural Resources and Life Sciences (Vienna, Austria), and Fischer (Fischerwerke Artur Fischer GmbH and Co. KG), an innovative low-damage prototype (new version of EQ-Rod) was developed and investigated through both experimental and numerical investigations (Pürgstaller 2017;Ciurlanti et al 2019;Pürgstaller et al 2020). The experimental campaign was carried out at the Structural Laboratory of Sapienza University of Rome in 2017 and complemented/extended the previous tests performed at the University of Canterbury introducing alternative testing configurations and anchorage detailing.…”

Influence of the anchorage shear hysteresis on the seismic response of nonstructural components in RC buildings

“…NSCs are commonly fixed to their host concrete structure by means of post-installed anchors (fasteners). It has been highlighted that the response of these NSCs against seismic actions strongly depends on the hysteresis behaviour of the anchor-connection (Pürgstaller 2017;Pürgstaller et al 2020). Compared to static loads, earthquake-induced actions result in more complex demands on the anchor (Hoehler 2006), including: cyclic loading (tension or shear dominated, or a combination of both), cyclic cracking of concrete, high loading rates, and large crack widths (Eligehausen et al 2006;Mahrenholtz 2013).…”

Determination of Seismic Role of Non-Structural Components On Earthquake Behaviour of RC Buildings Using Various Seismic Design Codes And Fault Distances

“…In order to achieve a smooth seismic performance, it is necessary to provide good coordination of structural and non-structural performance. NCs, generally referred to as secondary systems in the literature, include elements fixed to the floors, bearing elements and roof of a building and do not contribute to the dead, live or seismic load capacity of the structures (Pürgstaller et al 2020). These important components are generally classified in three different groups; (a) architectural components, (b) mechanical and electrical equipment, and (c) building contents (Villaverde 1997).…”