Non-rectangular reinforced concrete shear walls: Design issues and performance

Non-rectangular reinforced concrete shear walls are often used in building systems as a means of resisting lateral forces. Much of what is assumed about the behavior of these walls has been extrapolated from tests of rectangular walls or tests of non-rectangular walls subjected to unidirectional loading. A collaborative research effort is underway incorporating the National Science Foundation George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Multi-Axial Subassemblage Testing (MAST) System at the University of Minnesota to investigate the behavior of non-rectangular wall systems subjected to multi-directional loading. This paper discusses issues encountered in the design of a prototype T-shaped shear wall from a six-story office building assigned to Seismic Design Category D. Issues include investigation of the critical biaxial loading combination and direction, distribution of forces among individual walls in a floor level, and detailing of the wall to comply with the intent of the ACI 318-02 Building Code Requirements for Structural Concrete.