Download or read book Further Investigation of a New RC Slab column Connection for Improved Seismic Performance of Multi story Buildings written by Austin Ryan Anderson and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete Filled Steel Tube (CFST) columns have several advantages over reinforced concrete columns in that: (1) the steel tube provides confinement of the concrete and reduces damage to the concrete core, (2) they possess very high shear capacities, (3) the steel tube is placed at the optimum location for flexural resistance, and (4) they sustain large drift demands without damage. CFSTs also accelerate construction since: (1) the steel tube acts as permanent formwork, (2) in a slab-column system, the columns and slabs may be cast simultaneously, (3) most of the internal reinforcement can be eliminated. Previously an experimental program was undertaken to investigate a proposed connection for use in flat-plate construction. The connection consists of steel rings on either side of the column with post-tensioned bolts to connect the rings and provide active confinement to the slab. The forces are transferred from the upper column to the lower column through reinforcement welded to the inside of the tube of the lower column. The ring also increases the critical perimeter for shear. A four-specimen program investigated the impact of the following design variables: (1) ring size, (2) number of bolts within the ring flange, and (3) bolts outside of the ring. A reference specimen using conventional stud-rail detailing was built. This experimental program aimed to further that research by investigating the effect of slab depth on the connection. In addition, two full-scale push-through tests were conducted to better understand the two-way shear behavior of the proposed connection. The conventional stud-rail connection sustained damage at low drift levels, which resulted in loss of strength. This behavior compromises the integrity and resilience of flat-plate buildings. The new connection provides drift capacities of 4% or greater before strength loss and mitigates damage, meeting the structural objective of integrity and resilience after a large seismic event. The research suggests that the ring dimension depends on both the column size and thickness of the slab. Test results showed better behavior with two rows of bolts on the ring flange. Although bolts outside the ring are beneficial, this detail was deemed impractical for new construction but may be viable for increasing shear capacity in retrofit design. Two-way shear strength resulted in a higher capacity for the connection with the larger ring flange and that ACI predictions of capacity were conservative.

Download or read book A RC Slab to CFT Column Connection for Improved Seismic Behavior of Multi story Buildings written by Alec S. Yeutter and published by . This book was released on 2020 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slab-column systems are commonly used as the gravity system of reinforced concrete buildings in high seismic regions. These systems are economical and typically constructed using stud rails at the reinforcement for the slab-column connection. However, prior work indicates that these connections are susceptible to damage and may lose load-carrying capacity at drift demands between 2% and 4%. A research program was undertaken to investigate a new slab-column system which: (i) is economical, (ii) mitigates damage and (iii) can sustain large drifts without loss in strength. The system is novel in that it uses concrete filled steel tubes (CFSTs) as the columns; prior work has demonstrated that these components are ductile, with high flexural, axial and shear capacities. In addition, the tube eliminates the need for longitudinal and transverse internal reinforcement as well as column formwork, thereby reducing construction time. The connection replaces a traditional drop panel with sandwiched steel rings. The rings are connected to the slab with post-tensioned bolts, eliminating the need for stud-rail reinforcement. The steel tubes are prefabricated with the rings and the lower column has longitudinal reinforcement welded to it; this is the only reinforcement in the column and extends through the slab reinforcement into the upper tube of the upper CFST column. This longitudinal reinforcement facilitates load transfer as does the ring-bolt connection assembly. This new connection was investigated experimentally using full-scale tests. Four specimens were tested with the primary study parameters as follows: (i) ring dimension, (ii) bolt pattern. The results indicate that the connection can sustain 6% drift with minimal damage.

Download or read book Seismic Performance of High strength Concrete Columns in FRP Stay in place Formwork written by Togay Ozbakkaloglu and published by . This book was released on 2005 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NEHRP Recommended Provisions National Earthquake Hazards Reduction Program for Seismic Regulations for New Buildings and Other Structures Commentary written by United States. Federal Emergency Management Agency and published by . This book was released on 2001 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NEHRP Guidelines for the Seismic Rehabilitation of Buildings written by and published by . This book was released on 1997 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Based Seismic Design for Tall Buildings written by Ramin Golesorkhi and published by . This book was released on 2017-10-30 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance-Based Seismic Design (PBSD) is a structural design methodology that has become more common in urban centers around the world, particularly for the design of high-rise buildings. The primary benefit of PBSD is that it substantiates exceptions to prescribed code requirements, such as height limits applied to specific structural systems, and allows project teams to demonstrate higher performance levels for structures during a seismic event.However, the methodology also involves significantly more effort in the analysis and design stages, with verification of building performance required at multiple seismic demand levels using Nonlinear Response History Analysis (NRHA). The design process also requires substantial knowledge of overall building performance and analytical modeling, in order to proportion and detail structural systems to meet specific performance objectives.This CTBUH Technical Guide provides structural engineers, developers, and contractors with a general understanding of the PBSD process by presenting case studies that demonstrate the issues commonly encountered when using the methodology, along with their corresponding solutions. The guide also provides references to the latest industry guidelines, as applied in the western United States, with the goal of disseminating these methods to an international audience for the advancement and expansion of PBSD principles worldwide.

Download or read book Rapid Visual Screening of Buildings for Potential Seismic Hazards Supporting Documentation written by and published by Government Printing Office. This book was released on 2015 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Rapid Visual Screening (RVS) handbook can be used by trained personnel to identify, inventory, and screen buildings that are potentially seismically vulnerable. The RVS procedure comprises a method and several forms that help users to quickly identify, inventory, and score buildings according to their risk of collapse if hit by major earthquakes. The RVS handbook describes how to identify the structural type and key weakness characteristics, how to complete the screening forms, and how to manage a successful RVS program.

Download or read book Flexure and Shear Base mechanism for the Enhanced Resilience of RC Coupled High rise Buildings written by Jordyn Kent and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the development and analytical investigation of a flexure and shear yielding base-mechanism that improves the seismic performance of RC coupled wall high-rise buildings. Although current design practice achieves life safety and collapse prevention during major earthquake events, there is often extensive damage located in the plastic hinging regions including the wall bases and coupling beams. A system of buckling-restrained braces located below the core is implemented as an alternative seismic fuse. With this system, the first-mode and higher-mode responses of the structure are limited through a combination of flexural and shear yielding. Nonlinear time-history analyses have been carried out comparing the performance of a reference structure to this alternative design. Results demonstrate that the base-mechanism improves the overall performance of the structure by limiting damage and improving safety at all hazard levels. Connection details for the system and design steps are also proposed.

Download or read book Advances in Structural Technologies written by Sondipon Adhikari and published by Springer Nature. This book was released on 2020-09-25 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select proceedings of the National Conference on Advances in Structural Technology (CoAST 2019). It brings together different applied and technological aspects of structural engineering. The main topics covered in this book include solid mechanics, composite structures, fluid-structure interaction, soil-structure interaction, structural safety, and structural health monitoring. The book also focuses on emerging structural materials and the different behavior of civil, mechanical, and aerospace structural systems. Given its contents, this book will be a useful reference for researchers and practitioners working in structural safety and engineering.

Download or read book ACI Structural Journal written by and published by . This book was released on 2009 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resilient Infrastructure written by Sreevalsa Kolathayar and published by Springer Nature. This book was released on 2021-10-28 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the Virtual Conference on Disaster Risk Reduction (VCDRR 2021). This book discusses various relevant topics such as Disaster resilience and Infrastructure, Risk reduction and structural measures, Evidence based approach for DRR Case studies, Numerical modelling and Constructions methods, Prevention Methods and Safety Engineering, Cross cutting issue in DRR and Infrastructure etc. The book is also a comprehensive volume on multi-hazards and their management for a sustainable built environment. This book will be useful for academicians, research scholars and industry professionals working in the area of civil engineering and disaster management.

Download or read book Low damage Gravity Rocking Connection for Multi storey Moment Frame Buildings written by Mamoon Jamil and published by . This book was released on 2018 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the literature showed the lack of a truly effective damage avoidance solution for timber or hybrid timber moment resisting frames (MRFs). Full system damage avoidance self-centring behaviour is difficult to achieve with existing systems due to damage to the floor slab caused by beam-elongation. A novel gravity rocking, self-centring beam-column joint with inherent and supplemental friction energy dissipation is proposed for low-medium rise buildings in all seismic zones where earthquake actions are greater than wind. Steel columns and timber beams are used in the hybrid MRF such that both the beam and column are continuous thus avoiding beam-elongation altogether. Corbels on the columns support the beams and generate resistance and self-centring through rocking under the influence of gravity. Supplemental friction sliders at the top of the beams resist sliding of the floor whilst dissipating energy as the floor lifts on the corbels and returns. 1:20 scale tests of 3-storey one-by-two bay building based on an earlier iteration of the proposed concept served as proof-of-concept and highlighted areas for improvement. A 1:5 scale 3-storey one-by-one bay building was subsequently designed. Sub-assembly tests of the beam-top asymmetric friction sliders demonstrated repeatable hysteresis. Quasi-static tests of the full building demonstrated a 'flat bottomed' flag-shaped hysteresis. Shake table tests to a suite of seven earthquakes scaled for Wellington with site soil type D to the serviceability limit state (SLS), ultimate limit state (ULS) and maximum credible event (MCE) intensity corresponding to an average return period of 25, 500 and 2500 years respectively were conducted. Additional earthquake records from the 22 February 2011 Christchurch earthquakes we included. A peak drift of 0.6%, 2.5% and 3.8% was reached for the worst SLS, ULS and MCE earthquake respectively whereas a peak drift of 4.5% was reached for the worst Christchurch record for tests in the plane of the MRF. Bi-directional tests were also conducted with the building oriented at 45 degrees on the shake table and the excitation factored by 1.41 to maintain the component in the direction of the MRF. Shear walls with friction slider hold-downs which reached similar drifts to the MRF were provided in the orthogonal direction. Similar peak drifts were reached by the MRF in the bi-directional tests, when the excitation was amplified as intended. The building self-centred with a maximum residual drift of 0.06% in the dynamic tests and demonstrated no significant damage. The member actions were magnified by up to 100% due to impact upon return of the floor after uplift when the peak drift reached 4.5%. Nonetheless, all of the members and connections remained essentially linearelastic. The shake table was able to produce a limited peak velocity of 0.275 m/s and this limited the severity of several of the ULS, MCE and Christchurch earthquakes, especially the near-field records with a large velocity pulse. The full earthquakes with uncapped velocity were simulated in a numerical model developed in SAP2000. The corbel supports were modelled with the friction isolator link element and the top sliders were modelled with a multi-linear plastic link element in parallel with a friction spring damper. The friction spring damper simulated the increase in resistance with increasing joint rotation and a near zero return stiffness, as exhibited by the 1:5 scale test building. A good match was achieved between the test quasi-static global force-displacement response and the numerical model, except a less flat unloading curve in the numerical model. The peak drift from the shake table tests also matched well. Simulations were also run for the full velocity earthquakes, including vertical ground acceleration and different floor imposed load scenarios. Excessive drift was predicted by the numerical model for the full velocity near-field earthquakes at the MCE intensity and a rubber stiffener for increasing the post joint-opening stiffness was found to limit the drift to 4.8%. Vertical ground acceleration had little effect on the global response. The system generates most of its lateral resistance from the floor weight, therefore increasing the floor imposed load increased the peak drift, but less than it would if the resistance of the system did not increase due to the additional floor load. A seismic design procedure was discussed under the framework of the existing direct displacement-based design method. An expression for calculating the area-based equivalent viscous damping (EVD) was derived and a conservative correction factor of 0.8 was suggested. A high EVD of up to about 15% can be achieved with the proposed system at high displacement ductility levels if the resistance of the top friction sliders is maximised without compromising reliable return of the floor after uplift. Uniform strength joints with an equal corbel length up the height of the building and similar inter-storey drifts result in minimal relative inter-floor uplift, except between the first floor and ground. Guidelines for detailing the joint for damage avoidance including bi-directional movement were also developed.

Download or read book Seismic Design of Reinforced Concrete Buildings written by Jack Moehle and published by McGraw Hill Professional. This book was released on 2014-10-06 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: Complete coverage of earthquake-resistant concrete building design Written by a renowned seismic engineering expert, this authoritative resource discusses the theory and practice for the design and evaluation of earthquakeresisting reinforced concrete buildings. The book addresses the behavior of reinforced concrete materials, components, and systems subjected to routine and extreme loads, with an emphasis on response to earthquake loading. Design methods, both at a basic level as required by current building codes and at an advanced level needed for special problems such as seismic performance assessment, are described. Data and models useful for analyzing reinforced concrete structures as well as numerous illustrations, tables, and equations are included in this detailed reference. Seismic Design of Reinforced Concrete Buildings covers: Seismic design and performance verification Steel reinforcement Concrete Confined concrete Axially loaded members Moment and axial force Shear in beams, columns, and walls Development and anchorage Beam-column connections Slab-column and slab-wall connections Seismic design overview Special moment frames Special structural walls Gravity framing Diaphragms and collectors Foundations

Download or read book Inelastic Behavior of Direct RC Column to CFST Pile Connections written by Spencer Lindsley and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete filled steel tubes (CFSTs) are a composite structural component consisting of a steel tubewith concrete infill. Prior research has shown that CFST structural elements have greater strength and stiffness than typical reinforced concrete structural elements of similar size, result in economical structures, and also provide accelerated bridge construction. CFST members are quite suitable for piles and drilled shafts for deep foundations in bridge construction. While there has been both analytical and experimental research into CFST member behavior, there has been little research on connections of RC columns to CFST piles and drilled shafts. This research is an experimental study of a new connection between RC columns and CFST piles. In this research, half-scale column-to-pile connections were tested to evaluate their inelastic behavior under seismic loading. Four specimens were tested with the primary focus on the effects of (i) column reinforcement embedment depth, (ii) pile size, and (iii) the addition of a supplemental rib inside the pile. The nonlinear behavior was evaluated and the effects of these key parameters on the resistance, ductility, and deformation capacity were determined. The transfer of the force and moment from the RC column to the CFST pile were closely monitored. The experimental results were compared to nonlinear analyses performed with LS-Dyna computer program to calibrate models for future study and establish the accuracy of the models. The experiments found showed that the connections have excellent strength, ductility, and inelastic deformation capacity. The moment and force of the RC column were effectively transferred to the CFST pile with a nominal development length of the reinforcing bar. The test suggests that connections with a larger pile or a supplemental rib inside the pile, showed improved seismic performance, compared to connections with a smaller pile and no supplemental rib.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1997 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for earthquake resistant non engineered construction written by Arya, Anand S and published by UNESCO. This book was released on 2014-08-25 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances and Applications of Hybrid Simulation written by Wei Song and published by Frontiers Media SA. This book was released on 2021-01-13 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: