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.

Axial Hysteretic Modeling of Cold-Formed Steel Members for Computationally Efficient Seismic Simulation

Abstract: Analysis and design of cold-formed steel (CFS) structures subjected to seismic forces usually focuses on the behavior of systems such as strapped/sheathed shear walls. Experimental data from tests on these systems offers limited information concerning the seismic performance of the individual CFS components or other configurations of shear walls. Buckling and cross-sectional deformations (unique to thin-walled steel sections) highly influence the response under cyclic loading of CFS members and the associated systems. Therefore, accurate and computationally efficient hysteretic models are required to predict the seismic performance of individual CFS components and CFS buildings. Experimental data from twenty-four axial tests is utilized to calibrate a hysteretic model that represents the axial cyclic response of cold-formed steel C-section structural framing members. The model includes strength degradation, unloading stiffness degradation and pinching behavior of the observed experimental response. Model parameters and damage rules are calibrated for local, distortional and global buckling based on the hysteretic energy dissipated. The calibrated parameters can be utilized to develop a toolbox of nonlinear hysteretic springs to represent framing axial members in CFS structures for seismic analysis and facilitate performance based earthquake engineering of CFS structures.

Assessment of modal pushover analysis procedure for seismic evaluation of buckling–restrained braced frames

Abstract: Buckling-restrained braced frame (BRBF) has become a viable choice of lateral-force resisting system for earthquake resistant buildings as its hysteretic behaviour is non-degrading and much hysteretic energy can be dissipated. Meanwhile, an improved pushover analysis procedure, called Modal Pushover Analysis (MPA), has been proposed by Chopra and Goel [(2002), Earthquake spectra, 20(1), 255–271] to include contributions of higher ‘modes’ in estimating seismic demands of buildings. The MPA procedure was demonstrated to provide reasonably accurate seismic demands compared with non-linear response history analysis (NL-RHA) when analysing moment-resisting frames. This research further examined the bias and accuracy of MPA procedure when it is applied to analyse 3-, 6-, 10- and 14-storey BRBF buildings due to two sets of strong ground motions having 2% and 10% probability of being exceeded in 50 years. The MPA estimates are compared with ‘exact’ results from NL-RHA. It was found that the peak roof displacement...

A Study on Different Types of Base Isolation System over Fixed Based

Abstract: Based isolation is a technique which is used to prevent or reduce damage to a structure at a time of earthquake. It is a design principle by which flexible supports (isolators) are installed under every supporting point of a structure. It is generally located across a foundation (substructure) and superstructure. Seismic hazards are key concern for a earthquake prone areas of the world. Performance-based earthquake design has brought recent technological advances which has established new approach to construct earthquake resistant structure. Base isolation systems are progressively used technique for advanced earthquake resistance structure. The effect of different types of base isolator over earthquake resistant structures is studied in this paper. The work focuses on comparative study of different types of base isolators such as lead rubber bearings (LRB), friction pendulum bearings (FPB), elastomeric rubber bearing (ERB), high damping rubber bearings (HDRB), and low damping rubber bearing (LDRB) and compared for time period, base shear, fundamental period, frequency, storey drift, time history analysis, and displacement of the fixed base.

Passive and Semi-active Pseudo Negative Stiffness Control of Highway Bridge Benchmark Problem

Abstract: Active and semi-active control methods for reduction of the dynamic response of structures are emerging and some are being implemented in buildings and bridges. This vast growing technology ows to recent developments of sensing and digital control techniques. Semi-active control is a promising approach for the seismic response reduction in which the control offers the adaptability of active control without requiring the associated large power sources [1-10], since the external energy is only used to modify the dynamic properties (e.g., stiffness, damping, and friction level) of semi-active device during an earthquake attack. Therefore, the semi-active control devices can be considered as controllable passive devices. The problem lies on what algorithm should control this device so that the structural response is favorable under earthquake excitation. Earthquake input energy absorption capability of structural components described by hysteretic loops plays the key role in ensuring proper seismic performance of structures. Members that have stable and large hysteretic loops are considered as ductile have been proved successful in reducing seismic responses. For very important structures, energyabsorbing devices are added to structures so that the hysteretic loops are localized only at the devices. For seismic isolation techniques, for example, hysteretic loops are also employed at the isolation devices to reduce excessive displacement. In this study, passive and semi-active control devices combined with base isolation bearings are used to generate desirable hysteretic loops. The control algorithm is designed so that the combination of the variable damper and isolation bearings yields the desirable hysteretic loops [6-11]. SEMI-ACTIVE SKYHOOK CONTROL SYSTEM