Precast concrete wall with end columns (PreWEC) for earthquake resistant design

An innovative seismic resisting system consisting of a Precast Wall with End Columns (or PreWEC) has been developed, and its performance has been verified using large-scale cyclic testing. The wall and end columns in the PreWEC system are anchored individually to a foundation using unbonded post-tensioning. A newly designed, low-cost mild steel connector is used to connect the wall and end columns horizontally along the vertical joint. The connectors are easily replaceable and provide additional hysteretic energy dissipation to the system. The PreWEC system can be economically designed to have a lateral load carrying capacity similar to that of a comparable reinforced concrete wall, while minimizing damage and providing self-centering capability. In addition to confirming these benefits, the large-scale test demonstrated that the PreWEC system: (i) would provide superior seismic performance compared to other currently available structural wall systems especially for the precast industry; and (ii) meets all the mandatory acceptance criteria established by the American Concrete Institute (ACI) for special unbonded post-tensioned precast structural walls and building frame special reinforced concrete shear wall systems, as defined in the American Concrete Society of Civil Engineers (ASCE) 7-05.