Download or read book Analytical Evaluation of Diagonally reinforced Concrete Coupling Beams Under Lateral Loads written by Steven M. Barbachyn and published by . This book was released on 2011 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Coupling Beam Axial Restraint on Analysis and Design of Reinforced Concrete Coupled Walls written by Kamiar Kalbasi Anaraki and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reinforced concrete coupled shear walls are effective systems for resisting lateral loads, often used in mid to high-rise buildings in earthquake-prone areas. These walls usually feature openings for doors and windows, dividing a solid wall into two separate piers. The strength of these walls comes not just from the sum of two individual piers, but from wall piers cross-section and the framing action between the wall piers through the coupling beams. In an earthquake, coupling beams serve as fuse elements, distributing seismic energy throughout the height of the building. This not only reduces the bending stress at the base of the shear walls but also improves their overall strength, stiffness, and resistance to lateral forces. Properly designed coupling beams, with sufficient longitudinal, diagonal, and confinement reinforcement, can effectively absorb energy while maintaining significant strength and stiffness, even under large deformations.The objective of this study was to develop, calibrate, and validate a new coupling beam model that integrates axial and lateral interactions under cyclic loading conditions. This model aims to reliably predict the elastic and inelastic responses of diagonally reinforced coupling beam elements. The proposed analytical model incorporates a fiber-based concrete cross-section, and diagonal trusses to account for axial interactions between the nonlinearity in the steel and concrete along the beam's length. This feature allows the model to capture additional axial force developed in the element due to the axial restraint from the wall piers, thereby increasing or decreasing the lateral strength of the beam. Additionally, the model includes the slip-extension behavior between the coupling beam and the supporting wall through zero-length fiber-based elements at both ends of the beam. Finally, with the development of the new analytical model and recent advancements in understanding the shear strength of RC shear walls, a new coupled/core wall design approach has been introduced to optimize the design of RC core walls. A variety of archetypes have been designed, based on both current design practices and the proposed approach. Detailed analytical models have been developed, and the efficiency of the proposed design has been evaluated through nonlinear static and dynamic analyses. To conduct the dynamic analysis, suites of ground motions were selected using the CMS approach and scaled to the MCER level of hazard. It has been demonstrated that the designed archetypes based on proposed procedure provide a more reliable shear responses under seismic loading compared to current design practices.

Download or read book Progresses in European Earthquake Engineering and Seismology written by Radu Vacareanu and published by Springer Nature. This book was released on 2022-08-24 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book encompasses the most challenging topics in earthquake engineering and seismology aiming at seismic risk reduction and reveals the outstanding progresses made in Europe in the past four years. Earthquakes pose a significant threat to countries around the world. But, equipped with the right knowledge and tools, engineers and seismologists can support policy and decision makers and building officials in creating a safer future for all of us. In this paradigm, the Third European Conference on Earthquake Engineering and Seismology (3ECEES) is organized in Bucharest (Romania) in September 2022 by the Romanian Association for Earthquake Engineering, Technical University of Civil Engineering of Bucharest and National Institute for Earth Physics. This outstanding scientific event is the third in a series started in 2006 in Geneva, Switzerland and continued in 2014 in Istanbul, Turkey. The papers included in this book are written by the most prominent contemporary European scholars in the two-folded fields of 3ECEES. The Distinguished Nicholas Ambraseys, along with 28 invited lectures providing the best knowledge in the fields of earthquake engineering and seismology, are shared with the general readership of this book. The book is organized in three parts, as follows: (1) Seismicity, engineering seismology and seismic hazard, (2) Seismic risk assessment and mitigation, and (3) Structural earthquake engineering. The 29 contributed papers for this book are shared among these three parts almost equally. Chapter “The Challenge of the Integrated Seismic Strengthening and Environmental Upgrading of Existing Buildings” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

Download or read book Analytical Investigation Into the Effect of Axial Restraint on the Stiffness and Ductility of Diagonally Reinforced Concrete Coupling Beams written by Owen J. Bower and published by . This book was released on 2008 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of axial restraint on the stiffness and ductility of diagonally reinforced concrete coupling beams are investigated analytically through the use of finite element analysis. To provide accurate result without undue computational expense, a mesh sensitivity study is performed to determine the optimal mesh of the analysis. To validate the modeling technique, an analysis was performed reproducing experimental testing performed at the University of Cincinnati with good agreement between the two. An analysis was performed reproducing the experimental testing performed by Dr. Fortney at the University of Cincinnati. Finally, non-linear analysis of a prototype building utilizing the hysteretic response obtained from the finite element analysis for each case of axial restraint was performed. External axial restraint in diagonally reinforced concrete coupling beams is shown to increase the initial stiffness of the coupled core wall lateral force resisting system, as well as improve the post-peak stiffness and energy dissipation.

Download or read book Collapse Assessment of Reinforced Concrete Coupled Walls written by Negin Aryaee Tauberg and published by . This book was released on 2019 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT OF THE DISSERTATION Collapse Assessment of Reinforced Concrete Ductile Coupled Walls by Negin Aryaee Tauberg Doctor of Philosophy in Civil Engineering University of California, Los Angeles, 2019 Professor John Wright Wallace, Chair Reinforced concrete coupled shear walls are efficient lateral load resisting systems commonly constructed as part of core walls in mid to high-rise buildings. Coupled walls are constructed as a result of openings accommodating doorways and windows, thus separating a solid wall segment in two piers. Instead of summing the strength of two individual wall piers, the efficiency of the individual wall piers is improved by proper coupling of two adjacent walls linked by coupling beams. During earthquake shaking, coupling beams act as ductile fuses and dissipate seismic energy over the building height. This coupling action reduces the flexural demand at the base of the shear walls and results in increased strength, stiffness, and lateral load resistance. Coupling beams can dissipate energy well in the system and retain significant strength and stiffness through large displacement reversals when they are detailed to retain ductility with adequate longitudinal, diagonal, and confinement reinforcement. As part of this study, important parameters affecting the behavior of coupling beams and coupled wall systems are assessed. A thorough coupling beam database is compiled consisting of 104 individual beam specimen and 11 coupled wall system level tests. The database is used to derive trends for coupling beam effective stiffness and shear-deformation backbone relations. Based on a review of past experimental results, an expression is derived relating the coupling beam effective stiffness as a function of the beam aspect ratio, i.e., EcIeff/EcIg = 0.07ln/h, which represents the secant stiffness to yield and includes the stiffening impact of the slab and the post- tensioning stress. This expression has been adopted in the PEER TBI (2017) and LATBSDC (2017) guidelines. Experimental shear-deformation information from the database is also used to quantify plastic rotations at peak coupling beam shear strength and at strength loss. The subsequent part of this study focuses on proposing appropriate seismic response parameters for coupled wall systems. Current ASCE 7-16 and ACI 318-14 design provisions specify the same seismic response parameters to be used for coupled walls as are for special structural walls. However, well-designed coupled walls can have improved lateral performance and energy dissipation compared to uncoupled walls since part of the total overturning moment is resisted by coupling action and energy dissipation is distributed along the height of structure. In coordination with ASCE 7 and ACI 318, a new lateral system is introduced for Reinforced Concrete (RC) Ductile Coupled Walls as an assembly of walls with aspect ratio (hwcs/lw) greater than 2.0 which are linked by coupling beams having aspect ratios (ln/h) between 2.0 and 5.0. This study employs the FEMA P695 methodology to validate the proposed response modification factor of R = 8, deflection amplification factor of Cd = 8, and an overstrength factor of 0 = 2.5 for RC Ductile Coupled Walls. The collapse assessment studies include forty-one Archetypes designed using ASCE 7-16 and ACI 318-19 including new provisions that require wall shear amplification and a drift capacity check. The Archetypes vary in building height (6 to 30 stories), wall cross section (planar and flanged/core), coupling beam aspect ratio (ln/h = 2.0 to 5.0), and coupling beam reinforcement arrangement (conventionally reinforced and diagonally reinforced). Collapse of the Archetypes is evaluated using failure criteria models that account for flexural failure (concrete crushing, bar buckling, wall lateral instability, bar fracture), shear, and axial failures. In comparison to previous studies that have assumed failure to occur at a roof drift ratio of 5%, this study uses a conservative approach to define flexural failure as a 20% drop in lateral strength. Overall, nonlinear static pushover and incremental dynamic analysis results indicate that R = 8 and 0 = 2.5 are appropriate parameters for RC Ductile Coupled Wall systems that are designed per ASCE 7-16 and ACI 318-19 provisions.

Download or read book Computational Modeling of Conventionally Reinforced Concrete Coupling Beams written by Ajay Seshadri Shastri and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coupling beams are structural elements used to connect two or more shear walls. The most common material used in the construction of coupling beam is reinforced concrete. The use of coupling beams along with shear walls require them to resist large shear forces, while possessing sufficient ductility to dissipate the energy produced due to the lateral loads. This study has been undertaken to produce a computational model to replicate the behavior of conventionally reinforced coupling beams subjected to cyclic loading. The model is developed in the finite element analysis software ABAQUS. The concrete damaged plasticity model was used to simulate the behavior of concrete. A calibration model using a cantilever beam was produced to generate key parameters in the model that are later adapted into modeling of two coupling beams with aspect ratios: 1.5 and 3.6. The geometrical, material, and loading values are adapted from experimental specimens reported in the literature, and the experimental results are then used to validate the computational models. The results like evolution of damage parameter and crack propagation from this study are intended to provide guidance on finite element modeling of conventionally reinforced concrete coupling beams under cyclic lateral loading.

Download or read book Computational Modelling of Concrete Structures written by Günther Meschke and published by CRC Press. This book was released on 2018-01-31 with total page 1735 pages. Available in PDF, EPUB and Kindle. Book excerpt: The EURO-C conference series (Split 1984, Zell am See 1990, Innsbruck 1994, Badgastein 1998, St. Johann im Pongau 2003, Mayrhofen 2006, Schladming 2010, St. Anton am Arlberg 2014, and Bad Hofgastein 2018) brings together researchers and practising engineers concerned with theoretical, algorithmic and validation aspects associated with computational simulations of concrete and concrete structures. Computational Modelling of Concrete Structures reviews and discusses research advancements and the applicability and robustness of methods and models for reliable analysis of complex concrete, reinforced concrete and pre-stressed concrete structures in engineering practice. The contributions cover both computational mechanics and computational modelling aspects of the analysis and design of concrete and concrete structures: Multi-scale cement and concrete research: experiments and modelling Aging concrete: from very early ages to decades-long durability Advances in material modelling of plain concrete Analysis of reinforced concrete structures Steel-concrete interaction, fibre-reinforced concrete, and masonry Dynamic behaviour: from seismic retrofit to impact simulation Computational Modelling of Concrete Structures is of special interest to academics and researchers in computational concrete mechanics, as well as industry experts in complex nonlinear simulations of concrete structures.

Download or read book Advanced Methods for Seismic Performance Evaluation of Building Structures written by Sang Whan Han and published by MDPI. This book was released on 2021-01-21 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue was created to collect the most recent and novel research on seismic performance evaluation of building structures. This issue includes three important topics on seismic engineering for building structures: (1) seismic design and performance evaluation, (2) structural dynamics, and (3) seismic hazard and risk analysis. To protect building structures from earthquakes, it is necessary to conduct seismic performance evaluations on structures with reliable methods and to retrofit these structures appropriately using the results of the seismic performance evaluation.

Download or read book Current Perspectives and New Directions in Mechanics Modelling and Design of Structural Systems written by Alphose Zingoni and published by CRC Press. This book was released on 2022-09-05 with total page 749 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems comprises 330 papers that were presented at the Eighth International Conference on Structural Engineering, Mechanics and Computation (SEMC 2022, Cape Town, South Africa, 5-7 September 2022). The topics featured may be clustered into six broad categories that span the themes of mechanics, modelling and engineering design: (i) mechanics of materials (elasticity, plasticity, porous media, fracture, fatigue, damage, delamination, viscosity, creep, shrinkage, etc); (ii) mechanics of structures (dynamics, vibration, seismic response, soil-structure interaction, fluid-structure interaction, response to blast and impact, response to fire, structural stability, buckling, collapse behaviour); (iii) numerical modelling and experimental testing (numerical methods, simulation techniques, multi-scale modelling, computational modelling, laboratory testing, field testing, experimental measurements); (iv) design in traditional engineering materials (steel, concrete, steel-concrete composite, aluminium, masonry, timber); (v) innovative concepts, sustainable engineering and special structures (nanostructures, adaptive structures, smart structures, composite structures, glass structures, bio-inspired structures, shells, membranes, space structures, lightweight structures, etc); (vi) the engineering process and life-cycle considerations (conceptualisation, planning, analysis, design, optimization, construction, assembly, manufacture, maintenance, monitoring, assessment, repair, strengthening, retrofitting, decommissioning). Two versions of the papers are available: full papers of length 6 pages are included in an e-book, while short papers of length 2 pages, intended to be concise but self-contained summaries of the full papers, are in this printed book. This work will be of interest to civil, structural, mechanical, marine and aerospace engineers, as well as planners and architects.

Download or read book Earthquake Resistant Engineering Structures IX written by C. A. Brebbia and published by WIT Press. This book was released on 2013-07-08 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: In earthquake-prone regions of the world it is important not only to ensure that new facilities meet optimal standards but also that existing structures and infrastructure be retrofitted and rehabilitated. As world populations concentrate in urban areas, the stakes in human life and property of such natural disasters as earthquakes becomes higher and higher. This has been driving research on advances in the field. These advances are presented biennially at a conference organised by the Wessex Institute of Technology.The advances presented at the ninth conference in the series, which began in 1991 are presented in this book. The papers cover Plates and other geological risks; Earthquake prediction; Microzoning; Remote sensing / Monitoring / Early warning systems; Seismic codes; Seismic hazard and vulnerability; Tsunamis; Seismic isolation and energy dissipation; Structural dynamics; Building performance during earthquakes; Retrofitting; Lifelines; Material mechanics and characterisation; Nonlinear numerical analysis; Performance based design; Experimental studies; Forensic analysis; Safety and security; Socio-economic issues; Insurance related issues; Innovative technologies; Case studies.

Download or read book Large scale Testing of Steel reinforced Concrete SRC Coupling Beams Embedded Into Reinforced Concrete Structural Walls written by Christopher John Motter and published by . This book was released on 2014 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reinforced concrete structural walls provide an efficient lateral system for resisting seismic and wind loads. Coupling beams are commonly used to connect adjacent collinear structural walls to enhance building lateral strength and stiffness. Steel-Reinforced Concrete (SRC) coupling beams provide an alternative to reinforced concrete coupling beams, diagonally-reinforced for shorter spans and longitudinally-reinforced for longer spans, and offer potential advantages of reduced section depth, reduced congestion at the wall boundary region, improved degree of coupling for a given beam depth, and improved deformation capacity. Four large-scale, flexure-yielding, cantilever SRC coupling beams embedded into reinforced concrete structural walls were tested by applying quasi-static, reversed-cyclic loading to the coupling beam (shear) and the top of the wall (moment, shear, and constant axial load) to create cyclic tension and compression fields across the embedment region. The primary test variables were the structural steel section embedment length, beam span length (aspect ratio), quantities of wall boundary longitudinal and transverse reinforcement, and applied wall loading (moment, shear, and axial load). Based on test results, long embedment length, sufficient wall boundary reinforcement, and low-to-moderate wall demands across the embedment region are all associated with favorable coupling beam performance, characterized by minimal pinching and strength degradation in the load-deformation response and plastic hinge formation at the beam-wall interface with a lack of damage (plasticity) in the embedment region. The variation in aspect ratio was not found to significantly affect performance. Detailed design and modeling recommendations for steel reinforced concrete (SRC) coupling beams are provided for both code-based (prescriptive) design and alternative (non-prescriptive) design. For both code-based and alternative design, modeling a rigid beam for flexure and shear deformations with rotational springs at the beam-wall interfaces is recommended for stiffness, as test results indicate that the majority of the coupling beam deformations were associated with interface slip/extension. Alternative stiffness modeling recommendations are provided, in which an effective bending stiffness that accounts for the aspect ratio or beam length is used instead of interface rotational springs. A capacity design approach, in which the provided embedment strength exceeds the expected beam strength, is recommended for determining the required embedment length of the steel section into the structural wall. Recommendations for computing the nominal and expected (upper bound) flexure and shear strengths are provided. For alternative design, additional parameters are provided to define the strength and deformation capacity (to complete the backbone relations) and to address cyclic degradation for each of the test beams.

Download or read book Experimental Study of Reinforced Concrete Coupling Beams with Axial Restraint written by Bahaa Ahmad Burhan Al-Khateeb and published by . This book was released on 2021 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coupled shear walls are a lateral load resisting system used in buildings to resist seismic and wind loads. In coupled walls, coupling beams span between adjacent shear walls and are typically located at floor level. Coupling beams are designed to yield and form plastic hinges before the wall piers. Damage patterns observed after the 2010-2011 Canterbury earthquake sequence in New Zealand showed instances in which coupled walls did not behave as intended in design, as plastic hinges formed at the base of the wall piers but not at the beam ends. The Canterbury Earthquakes Royal Commission suggested that this undesirable response may have been caused by coupling beam axial restraint from walls and floors increasing the strength of the coupling beams.To better understand the effect of axial restraint on coupling beam behavior, seven one-half-scale reinforced concrete coupling beams were designed using ACI 318-19 and were constructed and tested. The main test variables were span-to-depth ratio, reinforcement configuration (conventional or diagonal), primary reinforcement ratio and bar diameter, and level of axial restraint. Six beams consisted of three identical pairs, with the two beams in each pair tested at a different level of constant stiffness axial restraint.Test results indicated that axial restraint, which is not included in the ACI 318-19 equation for nominal shear strength of diagonally reinforced coupling beams, increased the beam strength. Axial restraint also influenced the load-displacement responses of the beams and the observed damage patterns. The conventionally reinforced beams were observed to yield in shear, while damage concentrated at the ends of the diagonally reinforced beams. The onset of significant strength degradation in the diagonally reinforced beams was associated with buckling of diagonal reinforcement rather than crushing of confined concrete, such that variation in axial compression on identical pairs of beam did not lead to a significant difference in deformation capacity. Test beams with #6 diagonal reinforcement had improved deformation capacity over those with #4 diagonal reinforcement, due to the influence of the ratio of transverse reinforcement spacing to diagonal bar diameter (s/db) on bar buckling.

Download or read book Seismic Rehabilitation of Buildings written by and published by DIANE Publishing. This book was released on 1993-07 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Abstract Journal in Earthquake Engineering written by and published by . This book was released on 1993 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Earthquake Damaged Concrete and Masonry Wall Buildings written by Federal Emergency Agency and published by FEMA. This book was released on 2013-04-02 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following the two damaging California earthquakes in 1989 (Loma Prieta) and 1994 (Northridge), many concrete wall and masonry wall buildings were repaired using federal disaster assistance funding. The repairs were based on inconsistent criteria, giving rise to controversy regarding criteria for the repair of cracked concrete and masonry wall buildings. To help resolve this controversy, the Federal Emergency Management Agency (FEMA) initiated a project on evaluation and repair of earthquake damaged concrete and masonry wall buildings in 1996. The ATC-43 project addresses the investigation and evaluation of earthquake damage and discusses policy issues related to the repair and upgrade of earthquake damaged buildings. The project deals with buildings whose primary lateral-force-resisting systems consist of concrete or masonry bearing walls with flexible or rigid diaphragms, or whose vertical-load-bearing systems consist of concrete or steel frames with concrete or masonry infill panels. The intended audience is design engineers, building owners, building regulatory officials, and government agencies. The project results are reported in three documents. The FEMA 306 report, Evaluation of Earthquake Damaged Concrete and Masonry Wall Buildings, Basic Procedures Manual, provides guidance on evaluating damage and analyzing future performance. Included in the document are component damage classification guides, and test and inspection guides. FEMA 307, Evaluation of Earthquake Damaged Concrete and Masonry Wall Buildings, Technical Resources, contains supplemental information including results from a theoretical analysis of the effects of prior damage on single-degree-of-freedom mathematical models, additional background information on the component guides, and an example of the application of the basic procedures. FEMA 308, The Repair of Earthquake Damaged Concrete and Masonry Wall Buildings, discusses the policy issues pertaining to the repair of earthquake damaged buildings and illustrates how the procedures developed for the project can be used to provide a technically sound basis for policy decisions. It also provides guidance for the repair of damaged components.

Download or read book Nonlinear Modeling Parameters for Diagonally Reinforced Concrete Coupling Beams written by Dakota B. Saathoff and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A database of diagonally reinforced concrete coupling beam tests was formulated and used to assess strength, stiffness, and deformation capacity. The shear strength equation provided in ACI 318-19 considers only the transverse strength of the diagonal bars and was found to be overly conservative. A new equation that includes shear strength of concrete and transverse reinforcement was found to provide a better fit to test data. Existing recommendations were found to underestimate deformation capacity. A plastic hinge model that includes bond slip was formulated to estimate deformation capacity based on strain at crushing of confined concrete and strain at onset of diagonal reinforcement buckling. Favorable agreement was found between the model and test data. An empirical equation based on ratio of diagonal bar diameter to section depth, db/h, and ratio of spacing of transverse reinforcement to diagonal bar diameter, s/db, was fit to data. The empirical equation led to reduced scatter relative to the plastic hinge model. A parametric study was conducted using the plastic hinge model and the empirical equation, and reasonable agreement was found between the two models over this practical range of parameters. New recommendations for determining the deformation capacity of diagonally reinforced concrete coupling beams are provided.

Download or read book Behavior of Coupling Beams Under Load Reversals written by and published by . This book was released on 1980 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: