Download or read book Experimental and Analytical Studies on Reinforced Concrete Buildings with Seismically Vulnerable Beam column Joints written by Sangjoon Park and published by . This book was released on 2012 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Analytical Studies on Old Reinforced Concrete Buildings with Seismically Vulnerable Beam Column Joints written by SANGJOON. PARK and published by . This book was released on 2010 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Existing reinforced concrete (RC) buildings designed prior to 1970s are vulnerable to shear failure in beam-column joints under earthquake loads because of insufficient transverse reinforcement in the joint region. To assess the seismic risk of old RC buildings, the accurate prediction of shear strength and deformability for these unreinforced beam-column joints is essential. Several joint shear strength models are available in the literature but they have been originally developed to predict the shear strength of reinforced beam-column joints. Due to the different shear force transfer mechanism between reinforced and unreinforced beam-column joints, the existing models have little success to assess the shear strength of unreinforced beam-column joints. The ASCE/SEI 41-06 provisions specify shear strengths and backbone curves for unreinforced beam-column joints but the predictions using these provisions are usually conservative compared with many experimental test data collected from the literature. This study is focusing on developing accurate shear strength models and backbone relationships for unreinforced exterior and corner beam-column joints. This study proposes two shear strength models, semi-empirical and analytical, for unreinforced exterior and corner beam-column joints to reflect the influence of two key parameters: (1) joint aspect ratio which is defined as the ratio of beam to column cross-section heights, and (2) beam reinforcement index which is related to the amount of beam longitudinal reinforcement in tension. These key parameters are determined from a parametric study using a large experimental data set of unreinforced exterior and corner beam-column joints from the published literature. The proposed models are validated by accurate predictions of the shear strength for the database specimens. Besides the accuracy of the proposed models, the semi-empirical model has the advantage of straightforward extension to other types of beam-column joints. An important advantage of the analytical model is that for the case of beam yielding followed by joint failure, the analytical model can predict the reduced shear strength without the need for the complexity of ductility consideration. The experimental phase of this study includes testing four full-scale unreinforced corner beam-column joint specimens. These four specimens are designed to investigate the effect of the joint aspect ratio and the beam longitudinal reinforcement ratio. The test results show that the joint shear strengths are reduced with increase of the joint aspect ratio and for each of the joint aspect ratio, the joint shear strengths are proportional to the beam longitudinal reinforcement ratio within the range provided in the test specimens. The shear strengths of the four specimens are accurately predicted by the two proposed models, while the ASCE/SEI 41-06 provisions for shear strength produce conservative estimates of the strengths for the test specimens. Based on the measured joint shear stress-rotation and visual observation of the tested corner beam-column joint specimens, a multi-linear backbone relationship is proposed in this study to reflect the following beam-column joint responses: (1) initial joint cracking, (2) either beam reinforcement yielding or significant opening of existing joint cracks, (3) either existing joint cracks further propagation or additional joint cracks opening at the peak load, and (4) residual joint shear stress and rotation after severe damage in the joint. Corresponding parameters in the backbone relationship are defined from the comparison with test results. The proposed backbone relationship is verified by the simulations for beam-column subassemblies of the tested four specimens and other four planar exterior beam-column joint specimens from the literature. To investigate the effect of beam-column joint flexibility on the lateral response in a structural system level, nonlinear static and dynamic simulations are performed. These simulations indicate that beam-column joint flexibility is essential for older-type RC buildings characterized by having unreinforced beam-column joints. As an extension of this study, progressive collapse analysis for older-type RC buildings will be pursued with the proposed beam-column joint backbone relationships.
Download or read book Analytical and Experimental Assessment of Seismic Vulnerability of Beam Column Joints Without Transverse Reinforcement in Concrete Buildings written by Wael M. Hassan and published by . This book was released on 2011 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT Analytical and Experimental Assessment of Seismic Vulnerability of Beam-Column Joints without Transverse Reinforcement in Concrete Buildings by Wael Mohamed Hassan Doctor of Philosophy in Engineering - Civil and Environmental Engineering University of California, Berkeley Professor Jack P. Moehle, Chair Beam-column joints in concrete buildings are key components to ensure structural integrity of building performance under seismic loading. Earthquake reconnaissance has reported the substantial damage that can result from inadequate beam-column joints. In some cases, failure of older-type corner joints appears to have led to building collapse. Since the 1960s, many advances have been made to improve seismic performance of building components, including beam-column joints. New design and detailing approaches are expected to produce new construction that will perform satisfactorily during strong earthquake shaking. Much less attention has been focused on beam-column joints of older construction that may be seismically vulnerable. Concrete buildings constructed prior to developing details for ductility in the 1970s normally lack joint transverse reinforcement. The available literature concerning the performance of such joints is relatively limited, but concerns about performance exist. The current study aimed to improve understanding and assessment of seismic performance of unconfined exterior and corner beam-column joints in existing buildings. An extensive literature survey was performed, leading to development of a database of about a hundred tests. Study of the data enabled identification of the most important parameters and the effect of each parameter on the seismic performance. The available analytical models and guidelines for strength and deformability assessment of unconfined joints were surveyed and evaluated. In particular, The ASCE 41 existing building document proved to be substantially conservative in joint shear strength estimation. Upon identifying deficiencies in these models, two new joint shear strength models, a bond capacity model, and two axial capacity models designed and tailored specifically for unconfined beamcolumn joints were developed. The proposed models strongly correlated with previous test results. In the laboratory testing phase of the current study, four full-scale corner beam-column joint subassemblies, with slab included, were designed, built, instrumented, tested, and analyzed. The specimens were tested under unidirectional and bidirectional displacement-controlled quasi-static loading that incorporated varying axial loads that simulated overturning seismic moment effects. The axial loads varied between tension and high compression loads reaching about 50% of the column axial capacity. The test parameters were axial load level, loading history, joint aspect ratio, and beam reinforcement ratio. The test results proved that high axial load increases joint shear strength and decreases the deformability of joints failing in pure shear failure mode without beam yielding. On the contrary, high axial load did not affect the strength of joints failing in shear after significant beam yielding; however, it substantially increased their displacement ductility. Joint aspect ratio proved to be instrumental in deciding joint shear strength; that is the deeper the joint the lower the shear strength. Bidirectional loading reduced the apparent strength of the joint in the uniaxial principal axes. However, circular shear strength interaction is an appropriate approximation to predict the biaxial strength. The developed shear strength models predicted successfully the strength of test specimens. Based on the literature database investigation, the shear and axial capacity models developed and the test results of the current study, an analytical finite element component model based on a proposed joint shear stress-rotation backbone constitutive curve was developed to represent the behavior of unconfined beam-column joints in computer numerical simulations of concrete frame buildings. The proposed finite element model included the effect of axial load, mode of joint failure, joint aspect ratio and axial capacity of joint. The proposed backbone curve along with the developed joint element exhibited high accuracy in simulating the test response of the current test specimens as well as previous test joints. Finally, a parametric study was conducted to assess the axial failure vulnerability of unconfined beam-column joints based on the developed shear and axial capacity models. This parametric study compared the axial failure potential of unconfined beam-column joint with that of shear critical columns to provide a preliminary insight into the axial collapse vulnerability of older-type buildings during intense ground shaking.
Download or read book Seismic Rehabilitation of Existing Buildings written by American Society of Civil Engineers and published by ASCE Publications. This book was released on 2007 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Standard ASCE/SEI 41-06 presents the latest generation of performance-based seismic rehabilitation methodology.
Download or read book Nonlinear Finite Element Analysis of Reinforced Concrete Exterior Beam column Joints with Nonseismic Detailing written by James B. Deaton and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research investigated the behavior of nonseismically detailed reinforced concrete exterior beam-column joints subjected to bidirectional lateral cyclic loading using nonlinear finite element analysis (NLFEA). Beam-column joints constitute a critical component in the load path of reinforced concrete buildings due to their fundamental role in integrating the overall structural system. Earthquake reconnaissance reports reveal that failure of joints has contributed to partial or complete collapse of reinforced concrete buildings designed without consideration for large lateral loads, resulting in significant economic impact and loss of life. Such infrastructure exists throughout seismically active regions worldwide, and the large-scale risk associated with such deficiencies is not fully known. Computational strategies provide a useful complement to the existing experimental literature on joint behavior and are needed to more fully characterize the failure processes in seismically deficient beam-column joints subjected to realistic failure conditions. Prior to this study, vulnerable reinforced concrete corner beam-column joints including the slab had not been analyzed using nonlinear finite element analysis and compared with experimental results. The first part of this research focused on identification and validation of a constitutive modeling strategy capable of simulating the behaviors known to dominate failure of beam-column joints under cyclic lateral load using NLFEA. This prototype model was formulated by combining a rotating smeared crack concrete constitutive model with a reinforcing bar plasticity model and nonlinear bond-slip formulation. This model was systematically validated against experimental data, and parametric studies were conducted to determine the sensitivity of the response to various material properties. The prototype model was then used to simulate the cyclic response of four seismically deficient beam-column joints which had been previously evaluated experimentally. The simulated joints included: a one-way exterior joint, a two-way beam-column exterior corner joint, and a series of two-way beam-column-slab exterior corner joints with varying degrees of seismic vulnerability. The two-way corner joint specimens were evaluated under simultaneous cyclic bidirectional lateral and cyclic column axial loading. For each specimen, the ability of the prototype model to capture the strength, stiffness degradation, energy dissipation, joint shear strength, and progressive failure mechanisms (e.g. cracking) was demonstrated.
Download or read book Seismic Strengthening of Concrete Buildings Using FRP Composites written by and published by American Concrete Institute. This book was released on 2008 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This CD-ROM consists of eight papers that were presented by ACI Committee 440 at the Spring Convention in Atlanta, GA, in April 2007"--Site Web de l'éditeur
Download or read book Experimental and Analytical Study of Reinforced Concrete Interior Beam wide Column Joints for Seismic Performance written by Yi Ming Wu and published by . This book was released on 2002 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Vulnerability Assessment of Civil Engineering Structures at Multiple Scales written by Tiago Miguel Ferreira and published by Woodhead Publishing. This book was released on 2021-12-02 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic Vulnerability Assessment of Civil Engineering Structures at Multiple Scales: From Single Buildings to Large-Scale Assessment provides an integrated, multiscale platform for fundamental and applied studies on the seismic vulnerability assessment of civil engineering structures, including buildings with different materials and building typologies. The book shows how various outputs obtained from different scales and layers of assessment (from building scale to the urban area) can be used to outline and implement effective risk mitigation, response and recovery strategies. In addition, it highlights how significant advances in earthquake engineering research have been achieved with the rise of new technologies and techniques. The wide variety of construction and structural systems associated with the complex behavior of their materials significantly limits the application of current codes and building standards to the existing building stock, hence this book is a welcomed guide on new construction standards and practices. Provides the theoretical backgrounds on the most advanced seismic vulnerability assessment approaches at different scales and for most common building typologies Covers the most common building typologies and the materials they are made from, such as concrete, masonry, steel, timber and raw earth Presents practical guidelines on how the outputs coming from such approaches can be used to outline effective risk mitigation and emergency planning strategies
Download or read book Multi hazard Approaches to Civil Infrastructure Engineering written by Paolo Gardoni and published by Springer. This book was released on 2016-06-22 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection focuses on the development of novel approaches to address one of the most pressing challenges of civil engineering, namely the mitigation of natural hazards. Numerous engineering books to date have focused on, and illustrate considerable progress toward, mitigation of individual hazards (earthquakes, wind, and so forth.). The current volume addresses concerns related to overall safety, sustainability and resilience of the built environment when subject to multiple hazards: natural disaster events that are concurrent and either correlated (e.g., wind and surge); uncorrelated (e.g., earthquake and flood); cascading (e.g., fire following earthquake); or uncorrelated and occurring at different times (e.g., wind and earthquake). The authors examine a range of specific topics including methodologies for vulnerability assessment of structures, new techniques to reduce the system demands through control systems; instrumentation, monitoring and condition assessment of structures and foundations; new techniques for repairing structures that have suffered damage during past events, or for structures that have been found in need of strengthening; development of new design provisions that consider multiple hazards, as well as questions from law and the humanities relevant to the management of natural and human-made hazards.
Download or read book Experimental and Analytical Investigations on Behavior of Reinforced Concrete Exterior Beam column Joints Without and with Retrofitting written by Akanshu Sharma and published by . This book was released on 2013 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Analytical Studies on the Hysteretic Behavior of Reinforced Concrete Rectangular and T beams written by Shao-yeh Marshall Ma and published by . This book was released on 1975 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Analytical Study of Reinforced Concrete Beam column Joint Behavior Under Seismic Loading written by Nilanjan Mitra and published by . This book was released on 2007 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This particular component is chosen for investigation because, despite the fact that laboratory and post-earthquake reconnaissance suggest that joint stiffness and strength loss can have a significant impact on structural response, the inelastic response of these components is rarely considered in analysis or design.
Download or read book Earthquake Resistant Engineering Structures X written by C.A. Brebbia and published by WIT Press. This book was released on 2015-09-15 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing the latest research on preparation for and mitigation of future earthquakes, this book addresses an area of increasing importance to many areas around the world. It contains research presented at the ninth and latest in a series of biennial conferences on the topic organised by the Wessex Institute. As world population has concentrated in urban areas, we have seen the consequences of natural disasters take an ever higher toll in human life and property. Adding to this trend, earthquake activity is being registered in areas that were not previously very active, thus the need for research into the application of technological advances to the specific area of earthquake engineering. This volume presents those advances. The papers cover Seismic Isolation and Energy Dissipation; Building Performance During Earthquakes; Nonlinear Numerical Analysis; Performance Based Design; Experimental Studies; Seismic Hazard Evaluation and Microzoning for Structural Design; Seismic Hazard Assessment; Case Studies.
Download or read book Experimental and Analytical Study of Reinforced Concrete External Beam column Subjected to Cyclic Loading written by Yahia Bousri and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fiber Beam column Element for Seismic Response Analysis of Reinforced Concrete Structures written by Fabio Taucer and published by . This book was released on 1991 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SEAOC Blue Book written by and published by . This book was released on 2009 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This SEAOC Blue Book: Seismic Design Recommendations is the premier publication of the SEAOC Seismology Committee. The name Blue Book is renowned worldwide among engineers, researchers, and building officials. Since 1959, the SEAOC Blue Book, previously titled Recommended Lateral Force Requirements and Commentary, has been a prescient publication of earthquake engineering. The Blue Book has been at the vanguard of earthquake engineering in California and around the world. This edition of the Blue Books offers a series of articles, that cover specific topics, some related to a particular code provision and some more general relating to an area of practice. While different than the previous editions of the Blue Books, it builds upon the tremendous effort of those who have forged earthquake engineering practice via the previous half-century of Blue Book editions. The Blue Book provides: insight and discussion of earthquake engineering concepts; interpretations of sometimes ambiguous or conflicting provisions of various codes, standards, and guidelines; and practical guidance on design implementation.
Download or read book Experimental and Analytical Study of Seismic Damage and Retrofit of Lightly Reinforced Concrete Structures in Low Seismicity Zones written by Joseph M. Bracci and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
