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

Abstract

In recent years, the growing need for reducing non-structural damage after earthquakes has stimulated a dedicated effort to develop innovative types of fasteners for anchoring non-structural components (NSCs) to reinforced concrete (RC) host-structures. To contribute to such need, and building on previous research, this paper presents the results of a series of uni-directional shake-table tests of simulated NSCs anchored to concrete via: (1) expansion, and (2) chemical anchors; post-installed into: (a) uncracked, and (b) cracked concrete. Considering different construction details, the experimental investigation focused on traditional anchorage systems, alternative solutions comprising mortar filling into the gap clearance, and a low-damage system relying on supplemental damping devices, capable of reducing the acceleration of the NSCs as well as the force of the anchorage during seismic shakings. The experimental tests provided significant evidence on the beneficial effects of a dissipative anchorage protecting both the non-structural component and the anchorage itself, even during strong earthquakes. Moreover, when construction details allow to close the fixture clearance with a mortar filling, this stiffer solution provide an additional reduction of NSCs seismic accelerations and forces. Therefore, suggestions for further improvements of the adopted low-damage solution are also proposed.

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

“…For SM16 and SM10, in turn, they are conservative with respect to P95, meaning that the prescriptions of EC2 are exceeded in only a few of the cases. All the other code provisions for rigid fixtured NSC underestimate the results obtained with all of the anchor types, implying that the assumption of full rigidity does not appear to be adequate when the anchorage hysteresis is considered and there is no mortar filling the annular gap (Ciurlanti et al 2022).…”

“…In addition, Eurocode 2-4 requires the strength of anchors resisting in shear and having an annular gap to be divided by the parameter α gap , which accounts for extra dynamic effects (hammering or impact between fixture and rod, see Quintana Gallo et al (2018Gallo et al ( , 2019, Pürgstaller et al (2020), andCiurlanti et al (2022)). Including this factor into the design force leads to Eq.…”

“…In the case of anchors resisting shear actions and having an annular gap, α gap = 0.5, as specified for construction tolerances, which means an amplification of 2.0 of the design forces. Following Pürgstaller et al (2020) and Ciurlanti et al (2022), it was noted that this factor should also be included in the calculations of the forces affecting the NSC, as in Eq. ( 15).…”

Triaxial shake table testing of an integrated low‐damage building system

“…This paper provides an overview of the overall SERA research project focusing on design procedure, specimen construction details, testing setup and protocol, and experimental results. More information on the structural details—from design to manufacturing—and analytical versus numerical versus experimental response of the specimen can be found in Ciurlanti et al., 29 while the construction, seismic response and performance evaluation of the non‐structural elements is discussed in Bianchi et al 30 …”

“…Table 1 summarizes the key DDBD design parameters. As mentioned above, a detailed description of the design and dimensioning of the structural members can be found in Ciurlanti et al 29 …”