Download or read book Seismic Behavior of RCS Beam column Subassemblies and Frame Systems Designed Following a Joint Deformation based Capacity Design Approach written by Xuemei Liang and published by . This book was released on 2003 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Behavior of Eccentric Reinforced Concrete Beam column slab Connections written by Burcu Burak and published by . This book was released on 2005 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Behavior of Reinforced Concrete Column to steel Beam RCS Connections with Special Configurations written by Luis Bernardo Fargier-Gabaldón and published by . This book was released on 2005 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transactions of the American Society of Civil Engineers written by American Society of Civil Engineers and published by . This book was released on 2004 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 29-30 contain papers of the International Engineering Congress, Chicago, 1893; v. 54, pts. A-F, papers of the International Engineering Congress, St. Louis, 1904.

Download or read book Seventh U S National Conference on Earthquake Engineering written by Earthquake Engineering Research Institute and published by . This book was released on 2021 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the twenty-ninth volume in the Earthquake Engineering Research Institute's series, Connections: The EERI Oral History Series. EERI began this series to preserve the recollections of some of those who have had pioneering careers in the field of earthquake engineering. Significant, even revolutionary, changes have occurred in earthquake engineering since individuals first began thinking in modern, scientific ways about how to protect construction and society from earthquakes. The Connections series helps document this important history. This volume in the EERI Oral History Series presents the life and career of Anil K. Chopra, Professor Emeritus in the Department of Civil and Environmental Engineering at the University of California, Berkeley. After he graduated from college in India, he went to UC Berkeley to earn his Master's and PhD degrees, then taught at the University of Minnesota before returning to join the faculty of UC Berkeley for the next 47 years, retiring in 2016. The first class he was asked to teach at UC Berkeley was structural dynamics, a course which had been started by his mentors, Ray Clough and Joe Penzien. His work in that field resulted in a number of publications on a wide range of topics in earthquake engineering and structural dynamics. Chopra chaired the structural analysis committee of the project producing the influential ATC-3, Tentative Provisions for the Development of Seismic Regulations for Buildings, and he tells interesting stories about working with Nate Newmark, Emilio Rosenblueth, Henry Degenkolb, and others. His expertise in structural dynamics resulted in his being asked to write the EERI monograph on structural dynamics, Dynamics of Structures: A Primer, and later led to his very widely used university textbook, Dynamics of Structures: Theory and Application to Earthquake Engineering, now in its fifth edition. A major theme in Chopra's research is the seismic analysis and design of concrete dams. He and a number of PhD students developed procedures for earthquake analysis of concrete dams, and he has consulted on dozens of major projects around the world. In 2020 he published his comprehensive book on the subject, Earthquake Engineering for Concrete Dams: Analysis, Design, and Evaluation.

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 American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Behavior Strength and Retrofit of Exterior RC Column to steel Beam Connections written by Gustavo Parra-Montesinos and published by . This book was released on 2000 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Behavior Performance and Design of Steel Concentrically Braced Frame Systems written by Keith D. Palmer and published by . This book was released on 2012 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a research program on special concentrically braced frame (SCBF) and buckling-restrained braced frame (BRBF) systems. The study builds upon previous work performed as part of a research program supported by the George E. Brown Network for Earthquake Engineering Simulation (NEES) entitled "International Hybrid Simulation of Tomorrow's Braced Frame." This program was initiated due to practical and experimental evidence that SCBFs were not performing as intended by current seismic design provisions. The current study includes a comprehensive experimental and analytical program which included two first-of-its-kind, two-story, one-bay by one-bay SCBF and BRBFs experiments. The experiments were performed at the University of Minnesota NEES laboratory to take advantage of its ability to apply large-displacement bi-directional loading. The two specimens were configured with braces in two orthogonal bays framing into a ``shared'' column with a floor system designed and constructed to simulate realistic conditions. The first specimen, the SCBF, employed HSS3x3x1/4 braces in a single-story X-configuration with one continuous brace and a pair of spliced braces in the opposing direction. The second test specimen, the BRBF, employed pin-ended, collared BRBs in a single-diagonal configuration. The analytical study consisted of a large suite of finite element simulations aimed at identifying the main parameters that influence the damage at the beam-column-gusset connection region in BRBFs and to make recommendations for the design and detailing of this connection region. This research has resulted in a number of findings including the observation that out-of-plane loading and deformation had little impact on the drift and ductility capacity of the system when compared to planar frame test results. In fact, the drift capacity of the SCBF test frame was only 6% less than that of comparable planar frames while the ductility and cumulative ductility capacities of the BRBF exceeded that of many of the planar BRBF system tests. Based on the experimental and analytical findings, design and detailing recommendations were developed for the connection at the brace splice point in the single-story, X-configured system. Design and detailing recommendations were also made for the corner gusset plate connection region in BRBFs.

Download or read book Investigation on the Seismic Behavior of RC Interior Wide Beam column Connections written by Carlos G. Quintero-Febres and published by . This book was released on 1997 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Seismic Performance of Skewed Special Moment Frame Reduced Beam Section Connections written by Damaso Dominguez Vergara and published by . This book was released on 2020 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections and provides insights into allowable skew levels for design, widening the application of SMF RBS connections. The study presented herein involves parametric component-level analyses and system-level dynamic time-history analyses of skewed SMF RBS connections. The component-level parametric study involves detailed finite-element analysis of 64 SMF RBS connections and 48 SMF Welded Unreinforced Flange-Welded Web (WUF-W) connections (as a typical connection alternative to the RBS). The component-level investigation considers 3 skew angles, 4 column axial load levels and 3 beam-to-column connection geometries (shallow, medium, and deep column geometries). Connection capacity, column twist/yielding, connection response and fatigue performance are all investigated. Additional component-level composite (concrete-steel) connection simulations are conducted to investigate the effects of composite concrete slabs on the behavior of the skewed connections. In addition to the component-level analyses, system-level time-history analyses are used to investigate skewed SMF RBS connection demands during dynamic seismic loading. To investigate system-level effects on skewed connection behavior, a six-story building containing various levels of skew at the SMF connection is designed, simulated using detailed finite element procedures, and loaded using a scaled earthquake ground motion to represent both design basis and maximum considered earthquake demands. In addition to the detailed finite element investigations, an experimental testing program is designed and initiated to allow prequalification of skewed SMF RBS connections within the AISC provisions. Specimen fabrication, experimental setup (including instrumentation, loading, and boundary conditions), and initial results for the prequalification testing are described herein. Results from the component-level parametric research work indicate that SMF RBS connection capacity decreases when increasing the skew angle; however, all performance levels achieved would satisfy current AISC requirements for prequalification. Additionally, as skew angle is increased within the SMF RBS connection, the resulting column twist increases. Column flange-tip yielding is also observed at beam bottom-flange levels of the skewed geometries, and this yielding does increase for skewed connections having medium and deep column geometries when increasing the skew angle; however, the yielding is rather localized on the column flange. Local damage (indication of low-cycle fatigue fracture susceptibility) within the RBS section decreases when increasing the column axial load but does increase when increasing the skew angle. When a concrete slab is included, the connection's positive moment capacity increases due to composite action, but the result is increased column twist for medium and deep column geometries at rather large skew (30° skew relative to the column). A column twist prediction formula is developed and proposed.

Download or read book Seismic Behavior and Design of the Linked Column Steel Frame System for Rapid Return to Occupancy written by and published by . This book was released on 2016 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Linked Column Frame (LCF) is a new brace-free lateral structural steel system intended for rapid return to occupancy performance level. LCF is more resilient under a design level earthquake than the conventional approaches. The structural system consists of moment frames for gravity that combines with closely spaced dual columns (LC) interconnected with bolted links for the lateral system. The LC links are sacrificial and intended to be replaced following a design level earthquake. The centerpiece of this work was a unique full-scale experiment using hybrid simulation testing; a combination of physical test of a critical sub-system tied to a numerical model of the building frame. Hybrid simulation testing allows for full scale study at the system level accounting for the uncertainties via experimental component and having the ability to model more conventional behavior through numerical simulation. The experimental subsystem consisted of a two story LCF frame with a single bay while the remainder of the building was numerically modeled. Two actuators per story were connected to the specimen. The LC links have been designed to be short and plastically shear dominated and the LCF met the design intent of 2.5% inter-story drift limits. For evaluating the LCF response, hybrid testing was performed for ground motion at three different intensities; 50%, 10% and 2% probability of exceedence in 50 years for Seattle, Washington ground motions. The system overall had exhibited three distinct performance levels; linearly elastic, rapid return to occupancy where only the replaceable links would yield, and collapse prevention where the gravity beam components also became damaged. Results demonstrated a viable lateral system under cyclic and seismic loading, offering a ductile structural system with the ability to rapidly return to occupancy.

Download or read book Seismic Behavior of Semi rigid Steel Frames written by Hussam N. Mahmoud and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The widespread and unexpected damage to welded connections during recent earthquakes led to the investigation of alternatives for the construction of steel frames in seismic areas. Bolted semi-rigid connections have been recognized as an attractive alternative to welded connections. However, existing knowledge on the behavior of the connection is either from testing of beam-to-column subassemblies under idealized load and boundary conditions, or from analytical studies. In addition, the system-level experimental behavior of semi-rigidly connected frames using real earthquake motions to conclusively verify the full potential of semi-rigidity (implying also partial-strength) in earthquake resistance application is lacking. To this end, an advanced hybrid simulation approach for the seismic assessment of steel frames with semi-rigid connections was proposed and successfully completed. Furthermore, nonlinear dynamic response-history analyses of semi-rigid frames with varying design parameters were conducted to evaluate the system performance under seismic events. The results of the hybrid simulation and the parametric studies are used to quantify various fundamental code parameters needed for the seismic design of structures. The hybrid simulation included the most reliable, realistic, and computationally efficient experimental and analytical modules, which were developed and successfully integrated in a closed-loop system-level simulation. Three hybrid simulations were conducted on three different partial-strength semi-rigid frames with connection capacities that are a percentage of the plastic moment capacity of the beam (70% Mpbeam, 50% Mpbeam, and 30% Mpbeam). The simulations utilized the large-scale Multi-Axial Full-Scale Sub-Structured Testing and Simulation (MUST-SIM) facility at the University of Illinois and included a full-scale physical specimen for the experimental module and a 2D finite element model for the analytical module. The experimental component consisted of a beam-column subassembly with top-and seat-angle with double web-angle connecting the beam to the column. The analytical component is an inelastic finite element model with the connections modeled using a refined 2D continuum elements that is capable of capturing all relevant deformation and inelastic features of the connection. In addition to the hybrid simulation, nonlinear dynamic response-history analyses were conducted, on frames with three different connection capacities (70% Mpbeam, 50% Mpbeam, and 30% Mpbeam), using a collection of ground motion records scaled to the maximum considered earthquake (MCE). The analyses were aimed at investigating the effect of varying different design parameters on the seismic response and period elongation of the frames. The design parameters, in addition to connection strength, included yield strength of the angle material, coefficient of friction between faying surfaces, and the amount of slip allowed in the connection. The results of the hybrid simulation along with the analytical studies were used to evaluate more realistic fundamental code parameters needed for the seismic design of frames. The parameters included the equivalent damping ratio, 1̐ðeq, the inelastic period of the structure, Tinealstic, and a demand-based force reduction factor, Rdemand. The evaluated parameters can be used to better estimate the design base shear using a simplified design spectrum, allowing for safer and economical design of semi-rigid frames under seismic events.

Download or read book Seismic Behavior of Moment resisting Steel Column Bases written by Mohamed Fahmy and published by . This book was released on 2000 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analytical Modeling of the Seismic Behavior of Precast Concrete Frame Ductile Connections written by Stefano Pampanin and published by . This book was released on 2000 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Behavior of Reinforced Concrete Wide Concealed Beam narrow Column Joints written by Amer Mohammad Elsouri and published by . This book was released on 2011 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide and concealed beam- narrow column joints constitute an important part of reinforced concrete building structural systems in Lebanon and the region. Because Lebanon and most of the region are seismically active, evaluating the performance of these joints when subjected to earthquake loads becomes particularly important. A two-part experimental investigation was carried out. Part 1 concentrated on evaluating the seismic response of wide and concealed beam-narrow column joints when designed and detailed under gravity load in accordance with local design and construction practices (as-built). Part 2 focussed on exploring means for improving the seismic performance of the joints through adequate reinforcement detailing, guided by the ACI Building Code. Aspects of the seismic behavior that were evaluated throughout the research program included: (i) mode of joint failure, (ii) flexural and shear capacity, (iii) bond performance of the reinforcing bars, (iv) lateral drift capacity or ductility, (v) stiffness degradation, (vi) energy absorption and dissipation capacity under cyclic loading, and (vii) shear capacity of the joint core. In the first part of the investigation (Part 1), four full-scale interior and exterior beam-column sub-assemblages were tested under quasi-static cyclic loading. All specimens experienced extensive shear cracking within the joint core, and at drift ratios between 4.0% and 4.5%, the joint core experienced damage beyond repair. It was concluded that unless detailed to prevent or limit shear failure, the as-built joints under investigation are significantly weak to be considered as part of the earthquake lateral-load-resisting system. In the second part of the investigation (Part 2), four additional full-scale joints were tested under quasi-static cyclic loading. The joints, referred to as earthquake-resistant joints, were similar to the four joints tested in Part 1, except that the reinforcement details were improved in part in accordance with ACI 318-08 provisions for earthquake-resistant structures. The joints satisfied some of the ACI Building Code design and steel detailing requirements, but still violated the dimension limitations specified in the same code or recommended by ACI-ASCE Committee 352-02. The corresponding joints displayed a considerably improved seismic performance, manifested by preventing or delaying joint shear failure, higher lateral load and drift capacities, lower stiffness degradation, larger energy dissipation capacities and stable overall hysteretic response when compared with the as-built joints. In addition to the main two parts of the investigation described briefly above, the potential of upgrading the seismic-resistant joints tested in Part 2 using a combination of epoxy injection for repairing the major cracks and carbon fiber reinforced polymers (CFRP) composites for strengthening was also explored and experimentally evaluated. The repair and strengthening procedure used in this study, which was carried out with minimum labor and cost, resulted in significant improvement of the structural performance of the damaged joints. This improved performance was manifested by substantial stiffness recovery, enhanced lateral load capacity and low strength degradation under large lateral drifts, controlled cracking and damage, and reasonable regain of energy absorption and dissipation capacity.