Download or read book Seismic Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading written by Mahmoud Mohamad Hachem and published by . This book was released on 2002 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading written by Mahmoud M. Hachem and published by . This book was released on 2003 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the dynamic testing of 4 circular reinforced concrete bridge columns. The specimens were divided into 2 pairs, with each pair subjected to a different ground motion. Within each pair, one specimen was subjected to one component of the ground motion, while the other was subjected to 2 components. Two analytical studies were carried out for a wide array of column heights, diameters, and axial load intensities. The columns were subjected to large suites of ground motions scaled to match on average the design response spectrum.
Download or read book Seismic Performance of Circular Reinforced Concrete Columns Under Varying Axial Load written by Gianmario Benzoni and published by . This book was released on 1996 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of four circular reinforced concrete bridge columns, with different axial load regimes, is investigated. The first unit was tested under constant compressive axial load corresponding to an axial load ratio of 0.35. The second specimen was subjected to a constant tensile axial force equivalent to 0.087 axial load ratio. Two specimens were tested under varying regime of axial load, ranging between the two previous load limits, in order to simulate realistic seismic conditions of outer columns of multi-column bents. Extended comparison between experimental and predicted shear response, from different current equations, is provided.
Download or read book Seismic Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading written by Mahmoud Mohamad Hachem and published by . This book was released on 2002 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Performance of Circular Reinforced Concrete Bridge Columns Constructed with Grade 80 Reinforcement written by David Trejo and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This project assessed the use of ASTM A706 Grade 80 reinforcing bars in reinforced concrete columns. Grade 80 is not currently allowed in reinforced concrete columns due to lack of information on the material characteristics and column performance. Six half-scale, circular columns were tested: three constructed with Grade 60 reinforcement and three constructed with Grade 80 reinforcement. Designs followed standard design methodologies used by State Highway Agencies (including AASHTO). Results indicate that columns constructed with Grade 80 reinforcement performed similar to columns constructed with conventional ASTM A706 Grade 60 reinforcement. Computational modeling was performed using OpenSees for all six columns. Results indicate that the columns constructed with Grade 80 reinforcement achieved similar resistance and displacement and curvature ductility values when compared with the reference columns constructed with Grade 60 reinforcement. The columns constructed with Grade 60 reinforcement showed larger hysteretic energy dissipation than the columns constructed with Grade 80 reinforcement.
Download or read book Predicting Seismic Performance of Circular Reinforced Concrete Bridge Columns written by Hamid Anghaie and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The 2014 Canadian Highway Bridge Design Code (CHBDC) has been significantly modified to improve the seismic design and analysis of new bridges. Performance-Based Design has been implemented in the code as the main seismic design methodology for bridges. The goal of this research is to provide appropriate damage indicators that can be used in the performance-based design approach. Numerical models were developed using the Response-2000 program and the OpenSees platform. Nonlinear pushover analyses were conducted on a number of columns tested by other researchers. The numerical models were validated by comparing the predictions to the test results and the accuracy of the predictions was investigated. These studies provide guidance for engineers in the numerical modeling of bridge columns and also provide damage indicators for cover spalling, residual crack width, longitudinal bar buckling, and longitudinal bar fracture. " --
Download or read book Effects of Confinement and Flares on the Seismic Performance of Reinforced Concrete Bridge Columns written by Nadim I. Wehbe and published by . This book was released on 2001 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Steel Jacketing of Circular Reinforced Concrete Bridge Columns for Enhanced Flexural Performance written by Yuk Hon Chai and published by . This book was released on 1991 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Circular Spirally Reinforced Concrete Bridge Columns Under Seismic Loads written by Geraldine Soh Sim Cheok and published by . This book was released on 1986 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Performance of Well confined Concrete Bridge Columns written by Dawn Ellen Lehman and published by . This book was released on 2000 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Computational Evaluation of Reinforced Concrete Bridge Beam column Connections for Seismic Performance written by Clay Joshua Naito and published by . This book was released on 2001 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Response and Cost Characterization of Bridge Construction Using Seismic Performance Enhancement Strategies written by Ady Aviram Traubita and published by . This book was released on 2009 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: The improved seismic performance and cost-effectiveness of two innovative performance-enhancement technologies in typical reinforced concrete bridge construction in California were assessed in an analytical and experimental study. The technologies considered were lead rubber bearing isolators located underneath the superstructure and fiber-reinforced concrete for the construction of bridge piers. A typical five-span, single column-bent reinforced concrete overpass bridge was redesigned using the two strategies and modeled in OpenSees finite element program. Two alternative designs of the isolated bridge were considered; one with columns designed to remain elastic and the other such that minor yielding occurs in the columns (maximum displacement ductility demand of 2). The analytical model of the fiber-reinforced concrete bridge columns was calibrated using the results from two bidirectional cyclic tests on approximately 0¼-scale circular cantilever column specimens constructed using concrete with a 1.5% volume fraction of high-strength hooked steel fibers, relaxed transverse reinforcement, and two different longitudinal reinforcement details for the plastic hinge zone. Pushover and nonlinear time history analyses using 140 ground motions were carried out for the different bridge systems. The PEER performance-based earthquake engineering methodology was used to compute the post-earthquake repair cost and repair time of the bridges. Fragility curves displaying the probability of exceeding a specific repair cost and repair time thresholds were developed. The total cost of the bridges included the cost of new construction and post-earthquake repair cost required for a 75 year design life of the structures. The intensity-dependent repair time model for the different bridges was computed in terms of crew working days representing repair efforts. A financial analysis was performed that accounted for a wide range of discount rates and confidence intervals in the estimation of the mean annual post-earthquake repair cost. Despite slightly higher initial construction costs, considerable economic benefits and structural improvements were obtained from the use of the two performance-enhancement techniques considered, in comparison to the fixed-base conventionally reinforced concrete bridge, especially seismic isolation. The isolation of the bridge superstructure resulted in a significant reduction in both column and abutment displacement and force demands. The repair time of the isolated bridges was also significantly reduced, leading to continuous operation of the highway systems and reduced indirect economic losses. The experimental and analytical results also demonstrated that the use of fiber-reinforced concrete to build bridge columns leads to improved damage-tolerance, shear strength, and energy dissipation under cyclic loading compared to conventional reinforced concrete columns. These improvements result in better seismic performance and lower total 75-year cost of the fiber-reinforced column bridges.
Download or read book Optimization of Seismic Design of Single Column Circular Reinforced Concrete Bridge Piers written by Ravindra Verma and published by . This book was released on 1990 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation and Analysis of Circular Reinforced Concrete Bridge Columns for Investigating the Effect of Seismic Load History on Longitudinal Bar Buckling written by Yuhao Feng and published by . This book was released on 2013 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Load History on Reinforced Concrete Bridge Column Behavior written by Jason Goodnight and published by . This book was released on 2012 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: To satisfy the aims of performance based design, levels of damage which interrupt the serviceability of the structure or require more invasive repair techniques must be related to engineering criteria. In this report, the influence of displacement history on performance limit states, the relationship between strain and displacement, and the spread of plasticity in reinforced concrete structures is explored. An experimental study is underway to assess the performance of thirty circular, well-confined, bridge columns with varying lateral displacement history, transverse reinforcement detailing, axial load, aspect ratio, and longitudinal steel content. Eight of these columns, with similar geometry and detailing, were subjected to various unidirectional displacement histories including standardized laboratory cyclic loading and recreations of the displacement responses obtained from non-linear time history analysis of multiple earthquakes with distinct characteristics. Longitudinal reinforcing bars were instrumented to obtain strain hysteresis, vertical strain profiles, cross section curvatures, curvature distributions, and fixed-end rotations attributable to strain penetration. Results indicate that bar buckling was influenced by load history, but the relationship between strain and displacement along the envelope curve was not. The main impact of load history on bar buckling is its influence on accumulated strains within the longitudinal reinforcement and transverse steel.
Download or read book Use of Carbon Fiber Reinforced Polymer Sheets as Transverse Reinforcement in Bridge Columns written by Gamal Elnabelsya and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance of bridges during previous earthquakes has demonstrated that many structural failures could be attributed to seismic deficiencies in bridge columns. Lack of transverse reinforcement and inadequate splicing of longitudinal reinforcement in potential plastic hinge regions of columns constitute primary reasons for their poor performance. A number of column retrofit techniques have been developed and tested in the past. These techniques include steel jacketing, reinforced concrete jacketing and use of transverse prestressing (RetroBelt) for concrete confinement, shear strengthening and splice clamping. A new retrofit technique, involving fibre reinforced polymer (FRP) jacketing has emerged as a convenient and structurally sound alternative with improved durability. The new technique, although received acceptance in the construction industry, needs to be fully developed as a viable seismic retrofit methodology, supported by reliable design and construction procedures. The successful application of externally applied FRP jackets to existing columns, coupled with deteriorating bridge infrastructure, raised the possibility of using FRP reinforcement for new construction. Stay-in-place formwork, in the form of FRP tubes are being researched for its feasibility. The FRP stay-in-place tubes offer ease in construction, convenient formwork, and when left in place, the protection of concrete against environmental effects, including the protection of steel reinforcement against corrosion, while also serving as column transverse reinforcement. Combined experimental and analytical research was conducted in the current project to i) improve the performance of FRP column jacketing for existing bridge columns, and ii) to develop FRP stay-in-place formwork for new bridge columns. The experimental phase consisted of design, construction and testing of 7 full-scale reinforced concrete bridge columns under simulated seismic loading. The columns represented both existing seismically deficient bridge columns, and new columns in stay-in-place formwork. The existing columns were deficient in either shear, or flexure, where the flexural deficiencies stemmed from lack of concrete confinement and/or use of inadequately spliced longitudinal reinforcement. The test parameters included cross-sectional shape (circular or square), reinforcement splicing, column shear span for flexure and shear-dominant behaviour, FRP jacket thickness, as well as use of FRP tubes as stay-in-place formwork, with or without internally embedded FRP crossties. The columns were subjected to a constant axial compression and incrementally increasing inelastic deformation reversals. The results, presented and discussed in this thesis, indicate that the FRP retrofit methodology provides significant confinement to circular and square columns, improving column ductility substantially. The FRP jack also improved diagonal tension capacity of columns, changing brittle shear-dominant column behavior to ductile flexure dominant response. The jackets, when the transverse strains are controlled, are able to improve performance of inadequately spliced circular columns, while remain somewhat ineffective in improving the performance of spliced square columns. FRP stay-in-place formwork provides excellent ductility to circular and square columns in new concrete columns, offering tremendous potential for use in practice. The analytical phase of the project demonstrates that the current analytical techniques for column analysis can be used for columns with external FRP reinforcement, provided that appropriate material models are used for confined concrete, FRP composites and reinforcement steel. Plastic analysis for flexure, starting with sectional moment-curvature analysis and continuing into member analysis incorporating the formation of plastic hinging, provide excellent predictions of inelastic force-deformation envelopes of recorded hysteretic behaviour. A displacement based design procedure adapted to FRP jacketed columns, as well as columns in FRP stay-in-place formwork provide a reliable design procedure for both retrofitting existing columns and designing new FRP reinforced concrete columns.
Download or read book Seismic Performance of Reinforced Concrete Bridges Allowed to Uplift During Multi Directional Excitation written by Andres Oscar Espinoza and published by . This book was released on 2011 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract Seismic Performance of Reinforced Concrete Bridges Allowed to Uplift During Multi-Directional Excitation by Andres Oscar Espinoza Doctor of Philosophy in Engineering - Civil and Environmental Engineering University of California, Berkeley Professor Stephen A. Mahin, Chair The behavior of bridges subjected to recent moderate and large earthquakes has led to bridge design detailed for better seismic performance, particularly through wider bridge foundations to handle larger expected design forces. Foundation uplift, which is not employed in conventional bridge design, has been identified as an important mechanism, in conjunction with structural yielding and soil-structure interaction that may dissipate energy during earthquakes. Preventing uplift through wider foundations looks past the technical and economical feasibility of allowing foundation uplift during seismic events. The research presented in this thesis is part of a larger experimental and analytical investigation to develop and validate design methods for bridge piers on shallow foundations allowed to uplift during seismic events. Several analytical and some experimental studies have been performed to assess rocking and or uplift of shallow foundation systems, however they have evaluated systems with a limited range of footing dimensions and seismic excitations. As such, there is an uncertainty in the information needed to base a performance evaluation and develop design methods. The purpose of this study is to investigate, through experimental and analytical studies, the seismic performance of uplifting bridge piers on shallow foundations when considering different ground motions and footing dimensions. As well as to identify key differences in performance evaluation criteria for conventional and uplifting bridge pier systems. The experimental study dynamically tested a single reinforced concrete bridge column specimen with three adjustable footing configurations grouped by footing dimension, and tested for various combinations of one, two, and three components of seismic excitation. Groups one and two evaluated uplifting systems where the column was limited to elastic loading levels while group three considered inelastic column loading levels. All test groups remained stable and exhibited some rocking and or uplift during testing. Analytical models were developed and validated using the experimental testing results to predict local and global footing and column response. Reliable estimates of forces and displacements during elastic and inelastic response were achieved. To assess the seismic performance of a range of bridge pier systems allowed to uplift a parametric investigation using the validated analytical models was performed in which the column was modeled per conventional design criteria to ensure adequate strength and flexural ductility. The parameters varied include footing width, ground motion excitation, and elastic or inelastic column response. Response of the uplifting bridge pier systems was found to be sensitive to the structural periods, magnitude of excitation, and footing width.
