UC San Diego
Experimental and analytical investigation of the seismic performance of low-rise masonry veneer buildings
- Author(s): Okail, Hussein
- et al.
This dissertation presents an experimental and analytical evaluation of the seismic performance of clay masonry veneer in wood-stud buildings. The experimental program involved the shaking-table testing of eleven wall assemblies as well as a full-scale one-story building. Walls were subjected to separate in- and out-of-plane seismic excitation. The specimens had different anchor types, anchor spacing, aspect ratio, presence and absence of joint reinforcement and window openings. All the specimens were designed and constructed in accordance with the prescriptive requirements of the MSJC for masonry veneer for Seismic Design Categories D and E. The shaking- table tests showed that veneer complying with the current MSJC provisions can sustain ground motions far in excess of representative Design Basis and Maximum Considered Earthquakes for Seismic Design Categories D and E. The out -of-plane response was governed by the anchor axial strength. The in-plane response was characterized by veneer sliding for the squat panels and a combination of rocking and sliding for the slender ones. Experiments showed the possible reduction of the extraction capacities of the nails due to high moisture content in wood studs. Test data showed that veneers oriented parallel to the direction of shaking could restrain the wood structure. However, slender rocking veneer panels would induce additional seismic force to the wood structure under severe excitation. In the analytical phase of the research, numerical models were developed and calibrated by the experimental results. The models were capable of capturing the displacement and acceleration responses of the tested specimens as well as the failure mechanisms. The models were used to conduct parametric studies to examine the influence of different design variables on veneer response, including the effect of in-plane veneer on the seismic performance of wood-stud shear walls, and the behavior of two-story veneers under out-of-plane seismic excitation. The dissertation finally proposes a set of recommendations to improve current design provisions. Results highlighted the need for a minimum anchor strength requirement to assure a satisfactory level of performance under the Design Basis and Maximum Considered Earthquakes. The mass of the squat veneers oriented parallel to the direction of motion should not be treated as merely added mass