Modeling of lightly reinforced concrete walls subjected to near-fault and far-field earthquake ground motions

Reinforced concrete bearing walls with low vertical reinforcement ratios of less than 0-2% are referred to as lightly reinforced walls. Recently, Eurocode 8 and the French code PS 92 adopted a special design concept for lightly reinforced concrete walls based on the multifuse principle favouring rupture occurrence at several storeys. This design leads to lower reinforcement ratios with their optimized distribution allowing wide cracks to take place with large energy dissipation potential. In addition, the vertical displacement of the mass results in energy transformation from kinematic to potential. The objective of the investigation is to analytically predict the response of such lightly reinforced walls when subjected to near-fault and far-field ground motion records up to failure to establish the load-carrying capacity and ductility of the walls. A wall was modeled using six-node twodimensional panel elements. The panel elements have lumped flexural/axial plasticity at their top and bottom fibre sections. The response of the wall was evaluated in terms of pushover, spectral, displacement-based, and time history analyses. The model and the response data were verified against available measurements from a test program conducted using a shake table. The comparison indicated that the model closely represented the behaviour observed in the test. Copyright (c) 2007 John Wiley & Sons, Ltd.