Analytical modeling of squat walls with shear-controlled responses

In this study, a new finite element modeling methodology is implemented for simulating the in-plane hysteretic lateral load behavior of squat walls with aspect ratios not larger than 1.0, the response of which is governed by nonlinear shear deformations. The behavioral characteristics of the constitutive panel elements incorporated in the model formulation are based on a fixed crack angle modeling approach. Improvements are made on the constitutive panel model formulation, for better representation of the shearaggregate- interlock effects in concrete and dowel action on reinforcing bars, constituting the shear stress transfer mechanisms across the cracks. Sensitivity studies are conducted on the influence of parameters of the constitutive shear-aggregate-interlock and dowel action relationships on the model results. The model is extensively calibrated for eleven squat wall specimens and model predictions are compared with experimentally-measured lateral load vs. displacement responses. Response comparisons reveal that the model provides reasonable predictions of the lateral stiffness, lateral load capacity, and ductility characteristics of the wall specimens investigated. As well, implementation of a new constitutive model formulation for dowel action is shown to provide improved response predictions for lateral load values at large displacements, shape of the unloading/reloading loops, and pinching characteristics of the response. The modeling approach adopted in this study is believed to be a feasible candidate for reliable prediction of shear controlled Wall responses of squat walls under reversed-cyclic loading conditions.