Evaluation of the Seismic Response of Precast Wall Connections: Experimental Observations and Numerical Modeling

This research work is aimed at studying the seismic behavior of a lightly reinforced precast concrete wall system that is typical in northern European regions characterized by little or no natural seismicity. To this end, the authors tested pseudostatically, under in-plane cyclic loads, six full-scale panels representative of those commonly used for low- to mid-rise precast residential multi-unit terraced buildings in the Groningen region. Damage mechanisms and hysteretic capacity curves of wall assemblies with and without openings in their layout are presented so as to examine the seismic performance of these panels and their connections at progressively increased drift amplitudes. All specimens collapsed by a premature shear failure of their panel-to-panel joints, demonstrating that this type of connection is the weakest link of the wall system tested. The paper also discusses the main trends observed in terms of stiffness degradation and energy dissipation with the number of applied cycles and the imposed drift level. Furthermore, the authors carried out an additional set of push-pull tests of four panel subassemblies with variable wall thickness, with a view to specifically investigate the seismic response of this type of joint under asymmetric out-of-plane loading. Test results show that this type of connection system is characterized by visible pinching and low energy dissipation capacity. Based on this large campaign of experimental tests, a simple and computationally efficient numerical model is proposed for large scale seismic fragility analysis of precast terraced structures built with this particular technology.