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(Ed.)
Drywall partition walls are susceptible to damage at low-level drifts, and hence reducing such damage is key to achieving seismic resiliency in buildings. Prior tests on drywall partition walls have shown that slip track connection detailing leads to better performance than other detailing, such as fully-fixed connections. However, in all prior testing, partition wall performance was evaluated using a unidirectional loading protocol (either in-plane or out-of-plane) or in shake table testing. Moreover, all details are susceptible to considerable damage to wall intersections.
Two phases of the test have been performed at the Natural Hazards Engineering Research Infrastructure (NHERI) Lehigh Equipment Facility to develop improved details of drywall partition walls under bidirectional loading. The partition walls were tested alongside a cross-laminated timber (CLT) post-tensioned rocking wall subassembly, wherein the CLT system is under development as a resilient lateral system for tall timber buildings. In the Phase 1, the slip behavior of conventional slip-track detailing was compared to telescoping detailing (track-within-a-track deflection assembly). In the Phase 2, two details for reducing the wall intersection damage were evaluated on traditional slip-track C-shaped walls. First, a corner gap detail was tested. This detail incorporates a gap through the wall intersection to reduce the collision damage at two intersecting walls. Second, a distributed gap detail was tested. In this approach, the aim was to reduce damage by using more frequent control joints through the length of the wall. All walls were tested under a bidirectional loading protocol with three sub-cycles: in-plane, a bi-directional hexagonal load path, and a bi-directional hexagonal load path with an increase in the out-of-plane drift. This loading protocol allows for studying the bidirectional behavior of walls and evaluating the effect of out-of-plane drift on the partition wall resisting force.
In the Phase 1, the telescoping detailing performed better than conventional slip track detailing because it eliminated damage to the framing. In Phase 2, the distributed gap detailing delayed damage to about 1% story drift. For the corner gap detailing, the sacrificial corner bead detached at low drifts, but the wall itself was damage-free until 2.5% drift. Bidirectional loading was found to have an insignificant influence on the in-plane resistance of the walls, and the overall resistance of the walls was trivial compared to the CLT rocking.
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