Earthquake resistant structures

About: Earthquake resistant structures is a research topic. Over the lifetime, 1126 publications have been published within this topic receiving 27467 citations.

Experimental Evaluation of the Seismic Performance of Reinforced Concrete Bridge Columns

Abstract: A current focus in earthquake engineering research and practice is the development of seismic design procedures whose aim is to achieve a specified performance. To implement such procedures, engineers require methods to define damage in terms of engineering criteria. Previous experimental research on bridge columns has focused on component failure, with relatively little attention to other damage states. A research program was undertaken to assess the seismic performance of well-confined, circular-cross-section, reinforced concrete bridge columns at a range of damage states. The test variables included aspect ratio, longitudinal reinforcement ratio, spiral reinforcement ratio, axial load ratio, and the length of the well-confined region adjacent to the zone where plastic hinging is anticipated. The progression of damage was similar for all columns. Analysis of the experimental results suggest that key damage states of residual cracking, cover spalling, and core crushing can best be related to engineering parameters, such as longitudinal reinforcement tensile strain and concrete compressive strain, using cumulative probability curves.

Fragility Analysis of Retrofitted Multicolumn Bridge Bent Subjected to Near-Fault and Far-Field Ground Motion

Abstract: This paper focuses on the fragility-based seismic vulnerability assessment of retrofitted multicolumn bridge bents. Fragility curves are developed to assess the relative performance of various retrofit methods under both near-fault and far-field ground motions. A probabilistic seismic demand model (PSDM) is used in generating the fragility functions. Through nonlinear dynamic analysis, fragility curves are developed for multicolumn bridge bents retrofitted with four different retrofit techniques, specifically carbon fiber–reinforced polymer (CFRP) jacketing, steel jacketing, concrete jacketing, and engineered cementitious composite (ECC) jacketing. Following the performance-based evaluation approach, this study aims to investigate the effectiveness of different retrofitting methods to minimize the overall seismic vulnerability of deficient bridge bents. To investigate the seismic responses of the retrofitted bridge bents, a total of 40 earthquake excitations, of which 20 are near-fault and 20 are ...

Lateral Displacement Ductility of Reinforced Concrete Flat Plates

Abstract: It is presently unclear whether the reinforced concrete flat-slab connection possesses sufficient lateral displacement capacity to survive the lateral deformations that can be expected during a strong earthquake. The objective of this paper is to examine the available data from present and past research and from there develop an understanding of the major parameters that influence the lateral displacement capacity and ductility of reinforced concrete flat plates. The significant effects of gravity load and biaxial lateral loading are presented together with the implications of the findings with regard to seismic design and performance. An expression of the gravity level shear stress acting on the slab critical section to which it must be limited to insure adequate displacement ductility under extreme earthquake loading is given.

Performance-based plastic design (PBPD) method for earthquake-resistant structures: an overview

Abstract: This paper presents a brief overview of performance-based plastic design method as applied to the seismic design of building structures. The method uses pre-selected target drift and yield mechanisms as key performance criteria. The design base shear for a selected hazard level is calculated by equating the work needed to push the structure monotonically up to the target drift to that required by an equivalent single degree of freedom to achieve the same state. Plastic design is performed to detail the frame members and connections in order to achieve the targeted yield mechanism and behaviour. The method has been successfully applied to a variety of common steel framing systems and, more recently, to Reinforced Concrete (RC) moment frames. Results of extensive inelastic static and dynamic analyses showed that the frames developed desired strong column-sway mechanisms, and the storey drifts and ductility demands were well within the target values, thus meeting the desired performance objectives. The examples of 20-storey steel and RC moment frames, as presented in the paper, showed that the method is especially advantageous for tall frames, where cumbersome and lengthy iterative design work in current practice can be completely eliminated, while leading to excellent performance as targeted. The basic work-energy equation can also be used for seismic evaluation of existing structures. The results, as presented in this paper, showed excellent agreement with those obtained from more elaborate inelastic time-history analyses. Copyright © 2009 John Wiley & Sons, Ltd.