Journal of Structural Engineering-asce, Dec 1, 2019
AbstractA considerable amount of research studies have demonstrated the capability of metallic sa... more AbstractA considerable amount of research studies have demonstrated the capability of metallic sandwich panels in dissipating blast loading energy. Metallic sandwich panels dissipate blast energy t...
Journal of Structural Engineering-asce, Dec 1, 2020
AbstractIn typical wall load-bearing reinforced-masonry (RM) buildings, the lateral and vertical ... more AbstractIn typical wall load-bearing reinforced-masonry (RM) buildings, the lateral and vertical forces are resisted by rectangular shear walls. Thus, the walls are subjected to high vertical force...
Journal of Structural Engineering-asce, Apr 1, 2020
AbstractReinforced masonry buildings typically have a load-bearing wall structural system. Thus, ... more AbstractReinforced masonry buildings typically have a load-bearing wall structural system. Thus, the reinforced masonry shear walls must be capable of resisting both vertical forces from gravity lo...
Confining existing concrete and masonry columns by Carbon Fiber Reinforced Polymers (CFRP) is a b... more Confining existing concrete and masonry columns by Carbon Fiber Reinforced Polymers (CFRP) is a beneficial method for enhancing the column axial capacity and ductility. This paper presents an experimental investigation of the CFRP confinement influence on the uniaxial compression stress-strain behavior of concrete block masonry columns. Scaled fully grouted concrete block masonry columns, with a square cross section, were confined by continuous CFRP jackets and tested under concentric axial loading up to failure. The results indicate that CFRP enhances the ultimate axial strain and the axial load capacity by up to 281% and 79%, respectively compared to unreinforced columns. In this study, the effect of corner radius and the thickness of CFRP jackets are investigated. Special attention was also given to the effective tensile strain in the CFRP jackets. Finally, the CNR-DT 200 R1 confinement model, the only guide addressing strengthening masonry columns with external FRP composites, was assessed and refined equation is proposed.
Fiber optic sensors have been increasingly utilized in structural health monitoring of large-scal... more Fiber optic sensors have been increasingly utilized in structural health monitoring of large-scale civil structures. Bare fiber sensors are quite brittle, and therefore, their installation and embedment in reinforced concrete elements can be challenging, particularly when using uncommon materials as internal reinforcements in concrete. In the present study, a fiber optic strain sensor is preinstalled on a supplemental bar of adequate length and appropriate diameter. The sensor is attached to a glass fiber-reinforced polymer (GFRP) reinforcing bar in concrete flexural element. Performance under static-loading conditions has been evaluated, and the results have shown potential toward applying the technique to large-scale structures. Another objective of the present study is to develop a numerical model that represents the interaction between the concrete, the reinforcement steel, and the supplemental GFRP rebar, which has the sensor mounted on. The model is calibrated using experimental results. The model can be used to investigate varying parameters including material properties (e.g., compressive strength of concrete), geometrical data (e.g., the length of the supplemental rebar), and loading and boundary conditions, consequently eliminating the need to perform a large number of full-scale costly experiments. The developed model exhibited nearly identical behavior to the experiments after calibration. The study shows that the performance of the present sensing system is primarily affected by the relative sizes of the main and supplemental bars.
Abstract The concept of resilience is gaining increased attention in disaster management due to t... more Abstract The concept of resilience is gaining increased attention in disaster management due to the recent awareness of the need to reduce the detrimental post-event effects of natural disasters, e.g., earthquakes. Resilience is a practical concept that includes pre-event (preparedness and mitigation) and post-event (response and recovery) activities. Quantitative resilience assessment approaches are needed to compare the available mitigation strategies to decide on the most suitable strategy and provide better support for decision-making procedures. In this study, a methodology for quantifying the seismic resilience of reinforced masonry shear wall (RMSW) buildings with end-confined masonry boundary elements is implemented. The uncertainties associated with structural and non-structural losses and estimated recovery time uncertainties are considered while quantifying the resilience index of RMSW buildings. The archetype buildings studied have 8-, 10-, and 12-storey heights and are located in Vancouver, representing a high seismic zone in Canada. First, a numerical model was developed using OpenSees to derive the fragility surface for the studied archetypes subjected to bi-directional horizontal excitation. Second, a Monte Carlo simulation was performed to quantify the resilience index of each archetype considering the above-mentioned uncertainties. The results prove the robustness of ductile RMSW buildings having end-confined MBEs in mitigating the losses associated with disaster events. Additionally, the findings provide comprehensive and valuable information for earthquake mitigation measures and disaster risk reduction programmes.
Journal of Performance of Constructed Facilities, 2020
AbstractSeveral experimental and analytical studies have evaluated the seismic response of reinfo... more AbstractSeveral experimental and analytical studies have evaluated the seismic response of reinforced masonry (RM) shear walls either as a component (i.e., planar rectangular walls) or as a system ...
Journal of Performance of Constructed Facilities, 2017
AbstractMitigation of blast effects caused by accidental explosions is one of the major challenge... more AbstractMitigation of blast effects caused by accidental explosions is one of the major challenges in structural engineering. Fiber-reinforced polymer (FRP) sandwich panels offer promising systems for blast mitigation applications due to their considerable energy absorption compared to other materials with similar density. The FRP sandwich panels can have different inner core configurations that can be filled with other materials whenever needed. This paper numerically evaluates the effectiveness of new FRP honeycomb sandwich panels in resisting blast loads. A numerical model has been created using nonlinear explicit finite element simulation. Then, the model has been validated using the experimental field tests in the literature. Twelve FRP panels with different inner core configurations have been proposed to enhance the panels’ performance by reducing their peak deformation and increasing their energy dissipation. The paper also investigates the effect of filling the FRP sandwich panels with sand on the...
Journal of Structural Engineering-asce, Dec 1, 2019
AbstractA considerable amount of research studies have demonstrated the capability of metallic sa... more AbstractA considerable amount of research studies have demonstrated the capability of metallic sandwich panels in dissipating blast loading energy. Metallic sandwich panels dissipate blast energy t...
Journal of Structural Engineering-asce, Dec 1, 2020
AbstractIn typical wall load-bearing reinforced-masonry (RM) buildings, the lateral and vertical ... more AbstractIn typical wall load-bearing reinforced-masonry (RM) buildings, the lateral and vertical forces are resisted by rectangular shear walls. Thus, the walls are subjected to high vertical force...
Journal of Structural Engineering-asce, Apr 1, 2020
AbstractReinforced masonry buildings typically have a load-bearing wall structural system. Thus, ... more AbstractReinforced masonry buildings typically have a load-bearing wall structural system. Thus, the reinforced masonry shear walls must be capable of resisting both vertical forces from gravity lo...
Confining existing concrete and masonry columns by Carbon Fiber Reinforced Polymers (CFRP) is a b... more Confining existing concrete and masonry columns by Carbon Fiber Reinforced Polymers (CFRP) is a beneficial method for enhancing the column axial capacity and ductility. This paper presents an experimental investigation of the CFRP confinement influence on the uniaxial compression stress-strain behavior of concrete block masonry columns. Scaled fully grouted concrete block masonry columns, with a square cross section, were confined by continuous CFRP jackets and tested under concentric axial loading up to failure. The results indicate that CFRP enhances the ultimate axial strain and the axial load capacity by up to 281% and 79%, respectively compared to unreinforced columns. In this study, the effect of corner radius and the thickness of CFRP jackets are investigated. Special attention was also given to the effective tensile strain in the CFRP jackets. Finally, the CNR-DT 200 R1 confinement model, the only guide addressing strengthening masonry columns with external FRP composites, was assessed and refined equation is proposed.
Fiber optic sensors have been increasingly utilized in structural health monitoring of large-scal... more Fiber optic sensors have been increasingly utilized in structural health monitoring of large-scale civil structures. Bare fiber sensors are quite brittle, and therefore, their installation and embedment in reinforced concrete elements can be challenging, particularly when using uncommon materials as internal reinforcements in concrete. In the present study, a fiber optic strain sensor is preinstalled on a supplemental bar of adequate length and appropriate diameter. The sensor is attached to a glass fiber-reinforced polymer (GFRP) reinforcing bar in concrete flexural element. Performance under static-loading conditions has been evaluated, and the results have shown potential toward applying the technique to large-scale structures. Another objective of the present study is to develop a numerical model that represents the interaction between the concrete, the reinforcement steel, and the supplemental GFRP rebar, which has the sensor mounted on. The model is calibrated using experimental results. The model can be used to investigate varying parameters including material properties (e.g., compressive strength of concrete), geometrical data (e.g., the length of the supplemental rebar), and loading and boundary conditions, consequently eliminating the need to perform a large number of full-scale costly experiments. The developed model exhibited nearly identical behavior to the experiments after calibration. The study shows that the performance of the present sensing system is primarily affected by the relative sizes of the main and supplemental bars.
Abstract The concept of resilience is gaining increased attention in disaster management due to t... more Abstract The concept of resilience is gaining increased attention in disaster management due to the recent awareness of the need to reduce the detrimental post-event effects of natural disasters, e.g., earthquakes. Resilience is a practical concept that includes pre-event (preparedness and mitigation) and post-event (response and recovery) activities. Quantitative resilience assessment approaches are needed to compare the available mitigation strategies to decide on the most suitable strategy and provide better support for decision-making procedures. In this study, a methodology for quantifying the seismic resilience of reinforced masonry shear wall (RMSW) buildings with end-confined masonry boundary elements is implemented. The uncertainties associated with structural and non-structural losses and estimated recovery time uncertainties are considered while quantifying the resilience index of RMSW buildings. The archetype buildings studied have 8-, 10-, and 12-storey heights and are located in Vancouver, representing a high seismic zone in Canada. First, a numerical model was developed using OpenSees to derive the fragility surface for the studied archetypes subjected to bi-directional horizontal excitation. Second, a Monte Carlo simulation was performed to quantify the resilience index of each archetype considering the above-mentioned uncertainties. The results prove the robustness of ductile RMSW buildings having end-confined MBEs in mitigating the losses associated with disaster events. Additionally, the findings provide comprehensive and valuable information for earthquake mitigation measures and disaster risk reduction programmes.
Journal of Performance of Constructed Facilities, 2020
AbstractSeveral experimental and analytical studies have evaluated the seismic response of reinfo... more AbstractSeveral experimental and analytical studies have evaluated the seismic response of reinforced masonry (RM) shear walls either as a component (i.e., planar rectangular walls) or as a system ...
Journal of Performance of Constructed Facilities, 2017
AbstractMitigation of blast effects caused by accidental explosions is one of the major challenge... more AbstractMitigation of blast effects caused by accidental explosions is one of the major challenges in structural engineering. Fiber-reinforced polymer (FRP) sandwich panels offer promising systems for blast mitigation applications due to their considerable energy absorption compared to other materials with similar density. The FRP sandwich panels can have different inner core configurations that can be filled with other materials whenever needed. This paper numerically evaluates the effectiveness of new FRP honeycomb sandwich panels in resisting blast loads. A numerical model has been created using nonlinear explicit finite element simulation. Then, the model has been validated using the experimental field tests in the literature. Twelve FRP panels with different inner core configurations have been proposed to enhance the panels’ performance by reducing their peak deformation and increasing their energy dissipation. The paper also investigates the effect of filling the FRP sandwich panels with sand on the...
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Papers by Khaled Galal