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.

Performance-Based Earthquake Engineering: Opportunities and Implications for Geotechnical Engineering Practice

Abstract: Great advances have been made over the 40-some years in which geotechnical engineers have actively been involved in the practice of earthquake engineering. Most recently, advances have come through the development of performance-based earthquake engineering, which seeks to predict the seismic performance of structures and facilities in ways that are useful to a wide variety of stakeholders. Performance-based earthquake engineering requires the integrated, collaborative efforts of several groups of earthquake professionals, including geotechnical engineers; as such, it will affect the practice of geotechnical engineering in seismically active areas. This paper reviews the evolution of performance-based earthquake engineering, discusses the notion of performance and its description, and describes a recently developed framework for performance evaluation. The nature and effects of the many uncertainties that apply to the prediction and description of ground motions, system response, physical damage, and loss are described. The paper gives examples of different manners in which performance-based earthquake engineering can be implemented into practice. Finally, a series of challenges and opportunities presented by performance-based earthquake engineering for geotechnical engineering practitioners are identified and discussed.

Design considerations for slab-column connections in seismic zones

Abstract: The transfer of shearing forces and moments between concrete flat slabs and columns can produce brittle punching failure Slab-column connections must satisfy adequate strength against punching failure In seismic zones, the connections are expected to undergo deformations into the inelastic range and, hence, it is necesary to design connections with adequate strength and ductility In addition, the connections must be able to undergo a specified limit of interstory drift without punching failure The ductility and drift requirements that must be adhered to in design are discussed Tests reported in the literature show that the strength under cyclic moment transfer is less than the strength under monotonic loading For an earthquake-resistant structure, the design must be based on the strength under cyclic loading Test results are reviewed and discussed As an application, a hypothetical structure is designed according to American Concrete Institute (ACI) Building Code (ACI 318-89) The structure is subjected to the 1940 Elcentro ground motion, and time-history dynamic analysis is performed The results show that to obtain adequate strength, drift capacity, and ductile behavior of a slab-column connection without shear reinforcement, it is necessary in most cases to increase substantially the slab thickness in the connection region beyond the minimum thickness required to control deflections by providing shear capitals The disadvantages of shear captials can be avoided by using shear reinforcement

Selective upgrade of beam-column joints with composites

Abstract: The upgrade of seismic performance of existing reinforced concrete (RC), gravity load designed (GLD) structures is an important issue that involves economic as well as social aspects in different areas of the world. The strength hierarchy governs the upgrade requiring to protect the column and the panel so that the formation of a plastic hinge during a seismic event is in the beam. Presented is a technique based on FRP (fiber reinforced polymer) laminate and bar external installation for the seismic upgrade of RC beam-column joints. The technique was tested with an experimental program on 11 under-designed interior connections, obtaining selective upgrade while choosing different combinations and locations of sheets and bars in order to obtain different structural performance of joints. The paper summarizes selected results to underline how different parameters influenced the behavior of the joint in terms of strength and/or ductility.

Seismic shear capacity of reinforced masonry piers

Abstract: Masonry buildings have been, and remain, a popular form for economically enclosing space. Whereas such buildings are safe under gravity loads, most are vulnerable to horizontal loads due to earthquakes. Observations following an earthquake and experimental programs have shown that piers between openings are the most vulnerable part of a masonry building, and that the failure of such piers is due in the majority of cases to shear (or diagonal tension). Accordingly, the study described concerns the seismic response of reinforced masonry piers that exhibit a shear mode of failure. The study consists of two parts. First the results of an experimental program on reinforced masonry piers under cyclic lateral loads simulating seismic excitation are presented. Then several code provisions governing the seismic design of masonry are evaluated in view of the experimental observations, and a new seismic shear design concept is proposed for reinforced masonry piers and walls where the design strength is defined as th...

Development of deformable connection for earthquake‐resistant buildings to reduce floor accelerations and force responses

Abstract: Author(s): Tsampras, G; Sause, R; Zhang, D; Fleischman, RB; Restrepo, JI; Mar, D; Maffei, J | Abstract: This paper presents the development of a deformable connection that is used to connect each floor system of the flexible gravity load resisting system (GLRS) with the stiff lateral force resisting system (LFRS) of an earthquake-resistant building. It is shown that the deformable connection acts as a seismic response modification device, which limits the lateral forces transferred from each floor to the LFRS and allows relative motion between the GLRS and LFRS. In addition, the floor accelerations and the LFRS story shears related to the higher-mode responses are reduced. The dispersion of peak responses is also significantly reduced. Numerical simulations of the earthquake response of a 12-story reinforced concrete shear wall example building with deformable connections are used to define an approximate feasible design space for the deformable connection. The responses of the example building model with deformable connections and the example building model with rigid-elastic connections are compared. Two configurations of the deformable connection are studied. In one configuration, a buckling restrained brace is used as the limited-strength load-carrying hysteretic component of the deformable connection, and in the other configuration, a friction device is used. Low damping laminated rubber bearings are used in both configurations to ensure the out-of-plane stability of the LFRS and to provide post-elastic stiffness to the deformable connection. Important experimental results from full-scale tests of the deformable connections are presented and used to calibrate numerical models of the connections. Copyright © 2016 John Wiley a Sons, Ltd.