Applied Mechanics and Materials Vols. 353-356

Abstract: “strong beam and weak column”is the main failure states of reinforced concrete frame structure in the earthquake．This paper is the experimental study of the influence on the virtual cross-section bearing capacity on extremity of frame beam in reinforced concrete，which is affected by some element，such as slab reinforcement，the rigidity of orthogonal beam and so on．Exploring the mechanism of slab and frame work together to determine the width of effective flange，which provides references for structural design and engineering application．

Abstract: In order to discuss the effect of different concrete strength on the seismic behavior of the L-shape steel reinforced concrete (SRC) short-pier shear wall , this article analyze three L-shape steel reinforced concrete short-pier shear walls of different concrete strength with the numerical simulation software ABAQUS, revealing the effects of concrete strength on the walls seismic behavior. The results of the study show that the concrete strength obviously influence the seismic performance. With the concrete strength grade rise, the bearing capacity of the shear wall becomes large, the ductility becomes low, the pinch shrinkage effect of the hysteresis loop becomes more obvious.

Abstract: The seismic performance of multi-span simply supported steel-girder bridges with sliding and high rocker steel bearings is poor during earthquakes. During the past 20 years, seismic isolation has emerged as one of the most promising strategy for improving the seismic performance of existing bridges. In this study elastomeric bearings, lead-rubber bearings, and cable restrainers are attempted to modify the seismic response of bridges, and theirs effects are analyzed and compared.

Abstract: This paper presents the experimental investigations into the seismic failure for high arch dam with shaking table test. The similitude scale of high arch dam was studied firstly. Then we developed a like concrete material to simulate the mechanical behavior of the structural concrete in high arch dam. The shaking table tests have been performed on the scale model. The experimental results reveal the failure process of high arch dam with respect to the different earthquake intensities.

Abstract: Acceleration iterative control is generally used in multi-degrees-of-freedom earthquake simulation test. To overcome the shortcoming of poor displacement amplitude accuracy in this control, a multi-degrees-of-freedom earthquake simulation control strategy based on multi-movement parameters iterative control is proposed. This control divide the frequency range of earthquake simulation test into displacement control area, the synthetic control area and acceleration control area from the low frequency to the high frequency, and correct the acceleration errors spectrum and displacement error spectrum by iterative control method, and produce shaker driver signal by synthesis method, and realize the displacement replication and acceleration replication at the same time. The experimental results which are got in multi-degrees-of-freedom earthquake simulation facility indicate that this control can achieve high accuracy multi-degrees-of-freedom earthquake simulation test after several times iterative.

Abstract: To ensure seismic safety of a large span cable-stayed bridge, two alternative pylon shapes and section types were studied. Nonlinear time history analysis was performed in the context. It is found that the A-shaped pylon is much stiffener than the H-shaped pylon in terms of deformation. The steel A-shaped pylon can significantly reduce the seismic demands of the key member including tower drift and moment. A ductile steel link between towers is proposed for the optimization of design in the paper. The A-shaped reinforced concrete tower with ductile steel link was proved to be a relatively balanced plan considering engineering, aesthetic and economic factors.

Abstract: Seismic risk analysis is greatly helpful to seismic safety evaluation of dams. A preliminary study on seismic risk analysis of arch dam based on numerical simulation is presented. The numerical procedure approximately takes into account the influence of concrete heterogeneity, it can model the response of the dam from elastic vibration to ultimate failure. Five seismic damage levels including no damage, minor damage, medium damage, serious damage and collapse of dam are defined. Through Monte-Carlo analysis of nonlinear response of the dam, which considers uncertainty persistent in ground motion input as well as material properties of concrete, status of the dam after subjected to earthquakes is obtained. The final seismic risk of the dam, which conforms to the norm distribution, is reached based on data fitting. The results provide meaningful reference to seismic safety evaluation of the dam.

Abstract: The dynamic response control for a three layer steel frame structure with shape memory alloy (SMA) cables under seismic ground motions was studied experimentally in the paper. A three-story steel frame structure model assembling the diagonal SMA cables was tested in a shaking table. The maximum acceleration and displacement of each layer of the steel frame structure were tested under two cases: assembling with SMA cables or not. The experimental result shows that the maximum acceleration and displacement of each layer are significantly reduced by assembling the SMA cables. The vibration responses of the steel frame structure had been greatly reduced by the great dissipation efficiency for SMA dampers.

Abstract: Reinforced concrete (RC) columns are the vital members in bridge under the action of earthquake. In this paper, a modified Park-Ang damage model with nonlinear combination of the deformation and the hysteretic energy is proposed as a measure of RC bridge columns damage. The nonlinear combination coefficient of the modified model has been calculated based on the 151 cyclic test results of flexure dominant reinforced concrete columns. In additional, the correlation between performance levels and the values of damage index is presented. It is suggested that the scatter of the modified model at different performance levels is significantly reduced compared to the original Park-Ang damage model. At last, the probabilistic capacity models for RC bridge columns are applied to perform a damage analysis.

Abstract: Based on the theory of cantilever construction, combined with a three cross continuous rigid frame bridge, choosing the biggest cantilever stage, side span cross fold stages, middle span cross fold stage and complete bridge stage as the research object. Considering the pillar-soil function, making the seismic elastic-plastic response calculation. Getting the result that, during the earthquake, pillar-soil function can improve the flexible extension ability of the bridge structure so as to get better resistance seismic capacity. Internal force of the construction stage gradually reduces along the bottom pier, the middle pier and the top pier. Along the bridge, the maximum bending moment appears at the biggest cantilever stage. Horizontal to the bridge, the maximum bending moment appears at the side span cross fold stages. Plastic areas develops quickly during pier bottom and pile top, the crack is obvious; Plastic hinge first appears in the pile foundation, consuming earthquake energy through its plastic deformation so as to reduce the earthquake impact of pier. We should try to avoid plasticitys appearing in the pile foundation during the design, which will provide convenience for the follow-up maintenance.