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This paper presents a novel self-centering energy dissipating RC rocking column (SCERC) in which a steel tube protects the concrete from spalling and crushing at the column base. It incorporates an easily repairable pre-pressed disc spring self-centering device (SC) to restore the rocking column to its original position and a straightforward slip friction energy dissipation device (ED) to ensure adequate energy dissipation capacity. The working principle of the SC was investigated, and an analytical method was proposed. Subsequently, a theoretical hysteresis model for the SCERC considering different limit states is developed through reliable analyses. Lastly, the preliminary design parameters of the SCERC were determined, with numerical simulations conducted to validate the theoretical model. These simulations aim to explore the hysteresis characteristics, energy dissipation capabilities, and self-centering performance of the SCERC under different axial pressures and self-centering ratios. The results indicate that the theoretical hysteresis model was consistent with the numerical simulations, revealing that the SCERC exhibits a "flag-shaped" hysteresis response. The proposed SCERC displays satisfactory energy dissipation and self-centering characteristics. The SC provide sufficient restoring forces, with the EDs accounting for much of the energy dissipation. Plastic deformation was not observed in the concrete column, except for the unavoidable deformation occurring in the steel tube at the point of rotation. While a rocking column naturally possesses self-centering capabilities under axial forces, it requires SCs to counteract the negative stiffness caused by the P -∆ effect. As the self-centering ratio decreases, both the load capacity and energy dissipation capacity of the SCERC increase, leading to an increase in the residual deformation of the column; hence, the design should balance these two aspects for a suitable self-centering rate. • A rocking column with pre-pressed disc springs and enhanced column base is proposed. • A theoretical hysteresis model for different limit states is established. • Design parameters of the rocking column is investigated. • A numerical simulation is conducted to explore the resilient property. [ABSTRACT FROM AUTHOR]

This paper derives the theoretical equations to calculate the stiffness, strength, and yield displacement of the tall RC two-column piers with and without BRBs. A structural fuses-based design method was proposed to design the tall RC two-column piers with and without BRBs, and the corresponding scale models were designed and constructed. The numerical simulations and shaking table tests were separately conducted to verify the reasonable of the derivation theoretical equations and proposed design method and validate the effects of BRBs on controlling the seismic response and damage of the tall RC two-column pier. The seismic responses, including displacement and curvature, were discussed when the tall RC two-column piers with and without BRBs were subjected to different seismic waves. These results indicate that the BRB remarkably decreases the displacement and curvature of the column due to the BRBs yielding and dissipating the seismic energy. The seismic damage based on the yield curvature occurs in the tall RC two-column pier without BRBs, while the tall RC two-column pier with BRBs does not experience seismic damage under the design seismic waves with 0.4 g. Therefore, the BRBs can effectively control seismic damage and make the tall RC two-column pier satisfy the performance target according to the structural fuses concept. Also, the tall RC two-column piers with and without BRBs undergo seismic damage under the E2 earthquakes with 0.68 g. However, the curvature responses of the tall RC two-column pier with BRBs are far less than the tall RC two-column pier without BRBs under the E2 earthquakes. Consequently, BRBs can improve the seismic resilience of tall RC two-column piers. • Theoretical equations were derived for the strength and stiffness of a tall RC two-column pier with BRBs. • Dynamic simulations and tests were conducted for tall RC two-column piers with and without BRBs. • Seismic responses were compared for tall RC two-column piers with and without BRBs. • Theoretical equations were validated using dynamic simulations and tests. • BRBs effects on controlling seismic damage to tall RC two-column piers were verified. [ABSTRACT FROM AUTHOR]

The characterization of the constitutive mechanical behaviour of Fabric Reinforced Cementitious Composites (FRCM) is a widely discussed topic in the scientific community. Several research studies pointed out the difficulties in assessing reliable constitutive laws able to reproduce the local phenomena inner in the mechanics of FRCM materials. This paper presents the proposal of a model updating procedure based on a Genetic Algorithm (GA), able to obtain the parameters to be used for a simplified numerical modelling of the fabric-to-matrix interface. The procedure is applied to a truss-based Finite Element (FE) model, and it aims to minimize the difference between the simulations and the experimental results. The calibration procedure is performed against a large experimental database of bond tests in FRCM-to-masonry assemblies, allowing to express the model parameters as a function of geometrical and mechanical characteristics of the FRCM. • FRCM-to-masonry bond is studied. • A simplified FE model is proposed. • A GA-based model updating procedure is implemented. • Comparisons with experimental results prove the efficacy of the procedure. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical solution for bond-slip behavior of SRC interface based on experiment, numerical simulation, and theoretical derivation. Push-out tests of five specimens were firstly carried out, based on which, the simplified bond-slip model was proposed. The specimen was fabricated using the Q345H-shape steel (400 mm × 200 mm×13 mm × 8 mm) and C50 concrete (350 mm × 600 mm) with a bonding length of 500 mm. A FE model was established based on the bond-slip model to analyze the nonlinear bonding stress that are difficult to obtain from the experiment. The research shows that although the bonding stress in the elastic stage is not uniformly distributed, it is basically uniformly distributed when the ultimate bearing capacity is reached. It proves that assuming the average interfacial bonding stress under ultimate load to replace the maximum bonding stress is reasonable, which is crucial for designer to estimate interface bearing capacity and maximum bonding stress. Moreover, five different stages were obtained by the FE model analysis and the theoretical equations of bonding stress nonlinear distribution were obtained based on the boundary condition of each stage. The theoretical solution clearly showed the relationship between interface nonlinear stress distribution and influencing parameters including the bond area, elasticity modulus of material, section area of specimen, bond-slip constitutive model, and the external load. Based on the theoretical model, the influences of different parameters can be directly obtained without conducting further experiments and establishing different FE models. • The simplified bond-slip model was proposed and nonlinear distributiion of interfacial bonding stress was analyzed. • Assuming the average interfacial bonding stress under ultimate load to replace the maximum bonding stress is reasonable. • Corresponding analytical formulas for the interfacial stress in five different stages were established, respectively. • The theoretical solution showed the quantitative relationship between interface nonlinear stress and influencing parameters. [ABSTRACT FROM AUTHOR]

Surface ruptures resulting from seismic faulting have the potential to inflict substantial damage to bridges straddling fault lines; hence, it is imperative to investigate the impact of ground motions documented on either side of fault rupture planes—termed as across-fault ground motion—on the seismic resilience of bridges. In this paper, the object of study is a three-span, simply supported beam bridge traversing a strike-slip fault. Utilizing the LS-DYNA finite element software platform, a sophisticated three-dimensional finite element model of the selected bridge is constructed, meticulously accounting for material damage nonlinearity and structural collision contact nonlinearity. A synthetic across-fault ground motion serves as the excitation for the seismic analysis of the bridge, systematically examining the influence of the fault-crossing angle (FCA), fault sliding rise time, and ground surface permanent rupture displacement on the dynamic response and seismic damage incurred by the simply supported beam bridge. The findings demonstrate that a diminutive fault-crossing angle (FCA) corresponds to an elevated risk of longitudinal beam collapse when a simply supported beam bridge does not intersect a fault vertically. The impact of the fault sliding rise time on the magnitude of seismic response and damage sustained by the simply supported beam bridge is relatively minuscule and can be neglected. Conversely, the ground surface permanent rupture displacement profoundly influences the dynamic response and seismic damage of the bridge. The emergence of fling-step pulses from the development of ground surface permanent rupture displacement amidst seismic activity induces a shift in failure mode-from the designer-intended bending failure to an unforeseen shear failure. • A FE model of a simply-supported beam bridge is established with consideration of material and contact nonlinearity. • The systematic parameter analysis of the simply-supported beam bridge is conducted. • The failure mode and damage process of the simply-supported beam bridge are revealed. • Recommendations for the seismic design of simply-supported beam bridges subjected to strike-slip faulting are drawn. [ABSTRACT FROM AUTHOR]