A hybrid concrete wall is made up of a traditional reinforced concrete wall with post-tensioned technology. Recent research has shown that post-tensioned (PT) reinforced concrete shear walls have a wide range of advantages when it comes to resisting lateral forces and lateral moments caused by earthquake loading. To explore the PT reinforced concrete wall behavior subjected to seismic load, the concrete models were augmented with various material models, including the KCC, CDP, and Winfrith models for a PT 2D wall under pushover analysis. To ensure that the overall behavior forecast was qualitatively acceptable, the models’ performance was compared to experimental findings. Then, the post-tensioned modeling approach was implemented with the 3D wall in order to predict structural responses of the PT 3D wall. The well-validated finite element models were ultilized to estimate the effects of the post-tensioned bars on lateral resisting capacities of the precast concrete shear wall.
The paper presents an analytical investigation of the effect of vertical ground motion on the selected 13 reinforced concrete (RC) frames with different geometric configurations. For this purpose, earthquake ground motions with various vertical‐to‐horizontal peak acceleration ratios are selected to which a suitable scale factor is applied to match with seismic hazards of Korea. The methodology involves the evaluation of the structural responses of RC frames subjected to the selected records by means of nonlinear time history analyses. The results from the analysis are compared with results from studies of the case of horizontal‐only excitation. The effect of the vertical earthquake component on damage of RC frames is considered at both the global and the local levels. The effect of vertical ground motion on axial force, shear demand, and shear capacity of RC columns is investigated to assess failure on a local level. In particular, the shear capacity is evaluated by using both the conservative method of a design code and more realistic predictive approaches. The results of the extensive analyses indicate that vertical ground motion can significantly affect the response of RC members in terms of axial force variation and shear capacity. These results point to the conclusion that vertical ground motion needs to be included in analysis for assessment and design.
This paper evaluates the effect of construction quality defects on the seismic vulnerability of reinforced concrete (RC) frames. The variability in the construction quality of material properties and structural detailing is considered to assess the effect on the seismic behavior of RC frames. Concrete strength and yield strength of the reinforcement are selected as uncertain variables for the material properties, while the variabilities in the longitudinal reinforcement ratio and the volumetric ratio of transverse reinforcement are employed for structural detailing. Taking into account the selected construction quality uncertainties, the sensitivity analysis of the seismic vulnerability of the RC frames is performed and the impact of significant parameters is assessed at the global and local levels. This extensive analytical study reveals that the seismic vulnerability of the selected RC frame is particularly sensitive to concrete strength and the volumetric ratio of transverse reinforcement.
One of the most challenging elements of modeling the behaviour of reinforced concrete (RC) walls is combining realistic material models that can capture the observable behaviour of the physical system. Experiments with realistic loading rates and pressures reveal that steel and concrete display complicated nonlinear behaviour that is challenging to represent in a single constitutive model. To investigate the response of a reinforced concrete structure subjected to dynamic loads, this paper’s study is based on many different material models to assess the advantages and disadvantages of the models on 2D and 3D RC walls using the LS-DYNA program. The models consisted of the KCC model and the CDP model, which represented plasticity and distinct tensile/compressive damage models, and the Winfrith model, which represented plasticity and the smeared crack model. Subsequently, the models’ performances were assessed by comparing them to experimental data from reinforced concrete structures, in order to validate the accuracy of the overall behaviour prediction. The Winfrith model demonstrated satisfactory results in predicting the behaviour of 2D and 3D walls, including maximum strength, stiffness deterioration, and energy dissipation. The method accurately predicted the maximum strength of the Winfrith concrete model for the 2D wall with an error of 9.24% and for the 3D wall with errors of 3.28% in the X direction and 5.02% in the Y direction. The Winfrith model demonstrated higher precision in predicting dissipation energy for the 3D wall in both the X and Y directions, with errors of 6.84% and 6.62%, correspondingly. Additional parametric analyses were carried out to investigate structural behaviour, taking into account variables such as concrete strength, strain rate, mesh size, and the influence of the element type.
The paper investigates the seismic performance of rectangular RC columns retrofitted by a newly developed 3D Textile Reinforced Mortar (TRM) panel. The 3D-TRM used in this study consists of two components: self-leveling mortar and 3D textiles. Firstly, the flexural capacity of the 3D-TRM panel was investigated through the four-point flexural test. Secondly, a total of five specimens were constructed and experimentally investigated through static cyclic loading tests with constant axial load. One specimen was a non-seismically designed column without any retrofit, while the others were strengthened with either the 3D-TRM panel or conventional Fiber Reinforced Polymer (FRP) sheets. Experimental results in terms of hysteretic behavior, ductility ratio, and energy dissipation are investigated and compared with the cases of specimens with conventional retrofitting methods and without any retrofit. The maximum lateral force, ductility, stiffness degradation, and energy dissipation of RC columns with 3D-TRM panels were significantly improved compared with the conventional RC column. Therefore, it is concluded that the proposed retrofitting method can improve the seismic performance of non-conforming RC columns.