The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Yi Li - One of the best experts on this subject based on the ideXlab platform.
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A novel structural detailing for the improvement of seismic and progressive Collapse performances of RC frames
Earthquake Engineering & Structural Dynamics, 2019Co-Authors: Xinzheng Lu, Yi Li, Weidong Zhuo, Hong GuanAbstract:Earthquake‐induced building Collapse and progressive Collapse due to accidental local failure of vertical components are the two most common failure modes of reinforced concrete (RC) frame structures. Conventional Design methods usually focus on the Design requirements of a specific hazard but neglect the interactions between different Designs. For example, the progressive Collapse Design of an RC frame often yields increased reinforcement and flexural strength of the beams. As a result, the seismic Design principle of “strong‐column‐weak‐beam” may be violated, which may lead to unfavorable failure modes and weaken the seismic performance. To avoid these adverse effects of the progressive Collapse Design on the seismic resistance of RC frames, a novel structural detailing is proposed in this study. The proposed detailing technique intends to concurrently improve the seismic and progressive Collapse performances of an RC frame by changing the layout of the newly added longitudinal reinforcement against progressive Collapse without introducing any additional reinforcement. A six‐story RC frame is used as the prototype building for this investigation. Both cyclic and progressive Collapse tests are conducted to validate the performance of the proposed structural detailing. Based on the experimental results, detailed finite element (FE) models of the RC frame with different reinforcement layouts are established. The seismic and progressive Collapse resistances of different models are compared based on the incremental dynamic analysis (IDA) and nonlinear dynamic alternate path (AP) methods, respectively. The results indicate that the proposed structural detailing can effectively resolve the conflict between the seismic and progressive Collapse Designs.
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Improvement to composite frame systems for seismic and progressive Collapse resistance
Engineering Structures, 2019Co-Authors: Xinzheng Lu, Lei Zhang, Yi LiAbstract:Abstract Steel-concrete composite frame is one of the widely used structural systems. Earthquake and progressive Collapse due to accidental localized damage are the main hazards that affect the safety of steel-concrete composite frames. Therefore, a seismic and progressive Collapse resistant composite frame (SPCRCF) structural system is proposed based on a comprehensive consideration of the seismic and progressive Collapse Design requirements. The seismic and progressive Collapse performances of the proposed SPCRCF were compared with the conventional steel-concrete composite frame using the experimental results of four specimens. The general-purpose finite element software, MSC.Marc, was used to simulate the specimens. The experimental and simulation results show that the proposed SPCRCF has better seismic resilience (low damage, self-centering, and easy repair) and larger progressive Collapse resistance compared to conventionally Designed steel-concrete composite frames.
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Experimental study of a novel multi-hazard resistant prefabricated concrete frame structure
Soil Dynamics and Earthquake Engineering, 2019Co-Authors: Xinzheng Lu, Yi Li, Hong GuanAbstract:Abstract Reinforced concrete (RC) frames are one of the most commonly used structural systems worldwide. Earthquake actions and progressive Collapse caused by accidental local damage are two critical hazards increasing Collapse risks of multi-story RC frames. A significant difference is well recognized between the structural seismic Design and progressive Collapse Design. Whilst the seismic Design focuses on resisting the lateral forces due to earthquake, the progressive Collapse Design deals with resisting the unbalanced vertical load induced by a localized failure. Existing research has revealed that considering the two different Designs individually for a structure may lead to an undesirable overall structural performance and unnecessary waste of construction materials. In this study, a novel Multi-Hazard Resistant, Prefabricated Concrete (MHRPC) frame system is proposed to satisfy the demands of both structural seismic and progressive Collapse Designs. Cyclic and progressive Collapse tests are conducted to validate the performance of this newly proposed structural system. The mechanisms of the MHRPC frame system under both cyclic loads and a middle column removal scenario are analyzed based on the experimental results and numerical simulations using OpenSees. The results indicate that the proposed fame system exhibits such characteristics as large rotation, low damage, self-centering, and ease of repair. The system is also proven to be able to meet the multi-hazard Design requirements of RC frames against both earthquake actions and progressive Collapse.
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Experimental Study of Novel Concrete Frames Considering Earthquake and Progressive Collapse
Concrete Structures in Earthquake, 2019Co-Authors: Xinzheng Lu, Donglian Gu, Yi LiAbstract:Earthquake and progressive Collapse are two critical hazards increasing the Collapse risks of reinforced concrete (RC) frames. Existing research has revealed that considering the seismic Design and progressive Collapse Design individually for a structure may lead to an undesirable structural performance and unnecessary waste of materials. In this study, two novel concrete frames are proposed to satisfy the demands of both seismic and progressive Collapse Designs. The experimental results of seismic cyclic and progressive Collapse tests indicate that although implementing progressive Collapse Design can effectively enhance the progressive Collapse resistance of RC frame, the beam could be over-strengthened, resulting in a potential unfavorable “strong beam-weak column” failure mode. By contrast, the novel RC frame with a newly proposed structural detailing demonstrates a minor joint region damage with a satisfying progressive Collapse resistance. Moreover, the new prefabricated frame exhibits such characteristics as large rotation, low damage, self-centering, and ease of repair.
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Effects of Seismic and Progressive Collapse Designs on the Vulnerability of RC Frame Structures
Journal of Performance of Constructed Facilities, 2017Co-Authors: Yi Li, Xinzheng Lu, Hong GuanAbstract:AbstractBuildings are exposed to multiple natural hazards over their service lives. Multihazard analysis and Design of building structures has become a research hotspot worldwide. For these structures, earthquake and progressive Collapse are two of the most commonly encountered hazards. However, little research has been conducted to examine the effects of the seismic and progressive Collapse Designs on the resistance of buildings against multiple hazards. In this study, a series of six-story reinforced concrete (RC) frames are considered, and their seismic and progressive Collapse Designs are performed independently according to the corresponding Design codes. Fragility curves are used to assess the seismic and progressive Collapse resistance. The interactions between the two Designs are discussed by analyzing the fragility curves and the Collapse modes. Results show that the progressive Collapse Design of the RC frame may lead to an undesirable failure mode (i.e., strong-beam-weak-column) under earthquak...
Hong Guan - One of the best experts on this subject based on the ideXlab platform.
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A novel structural detailing for the improvement of seismic and progressive Collapse performances of RC frames
Earthquake Engineering & Structural Dynamics, 2019Co-Authors: Xinzheng Lu, Yi Li, Weidong Zhuo, Hong GuanAbstract:Earthquake‐induced building Collapse and progressive Collapse due to accidental local failure of vertical components are the two most common failure modes of reinforced concrete (RC) frame structures. Conventional Design methods usually focus on the Design requirements of a specific hazard but neglect the interactions between different Designs. For example, the progressive Collapse Design of an RC frame often yields increased reinforcement and flexural strength of the beams. As a result, the seismic Design principle of “strong‐column‐weak‐beam” may be violated, which may lead to unfavorable failure modes and weaken the seismic performance. To avoid these adverse effects of the progressive Collapse Design on the seismic resistance of RC frames, a novel structural detailing is proposed in this study. The proposed detailing technique intends to concurrently improve the seismic and progressive Collapse performances of an RC frame by changing the layout of the newly added longitudinal reinforcement against progressive Collapse without introducing any additional reinforcement. A six‐story RC frame is used as the prototype building for this investigation. Both cyclic and progressive Collapse tests are conducted to validate the performance of the proposed structural detailing. Based on the experimental results, detailed finite element (FE) models of the RC frame with different reinforcement layouts are established. The seismic and progressive Collapse resistances of different models are compared based on the incremental dynamic analysis (IDA) and nonlinear dynamic alternate path (AP) methods, respectively. The results indicate that the proposed structural detailing can effectively resolve the conflict between the seismic and progressive Collapse Designs.
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Experimental study of a novel multi-hazard resistant prefabricated concrete frame structure
Soil Dynamics and Earthquake Engineering, 2019Co-Authors: Xinzheng Lu, Yi Li, Hong GuanAbstract:Abstract Reinforced concrete (RC) frames are one of the most commonly used structural systems worldwide. Earthquake actions and progressive Collapse caused by accidental local damage are two critical hazards increasing Collapse risks of multi-story RC frames. A significant difference is well recognized between the structural seismic Design and progressive Collapse Design. Whilst the seismic Design focuses on resisting the lateral forces due to earthquake, the progressive Collapse Design deals with resisting the unbalanced vertical load induced by a localized failure. Existing research has revealed that considering the two different Designs individually for a structure may lead to an undesirable overall structural performance and unnecessary waste of construction materials. In this study, a novel Multi-Hazard Resistant, Prefabricated Concrete (MHRPC) frame system is proposed to satisfy the demands of both structural seismic and progressive Collapse Designs. Cyclic and progressive Collapse tests are conducted to validate the performance of this newly proposed structural system. The mechanisms of the MHRPC frame system under both cyclic loads and a middle column removal scenario are analyzed based on the experimental results and numerical simulations using OpenSees. The results indicate that the proposed fame system exhibits such characteristics as large rotation, low damage, self-centering, and ease of repair. The system is also proven to be able to meet the multi-hazard Design requirements of RC frames against both earthquake actions and progressive Collapse.
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Effects of Seismic and Progressive Collapse Designs on the Vulnerability of RC Frame Structures
Journal of Performance of Constructed Facilities, 2017Co-Authors: Yi Li, Xinzheng Lu, Hong GuanAbstract:AbstractBuildings are exposed to multiple natural hazards over their service lives. Multihazard analysis and Design of building structures has become a research hotspot worldwide. For these structures, earthquake and progressive Collapse are two of the most commonly encountered hazards. However, little research has been conducted to examine the effects of the seismic and progressive Collapse Designs on the resistance of buildings against multiple hazards. In this study, a series of six-story reinforced concrete (RC) frames are considered, and their seismic and progressive Collapse Designs are performed independently according to the corresponding Design codes. Fragility curves are used to assess the seismic and progressive Collapse resistance. The interactions between the two Designs are discussed by analyzing the fragility curves and the Collapse modes. Results show that the progressive Collapse Design of the RC frame may lead to an undesirable failure mode (i.e., strong-beam-weak-column) under earthquak...
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an energy based assessment on dynamic amplification factor for linear static analysis in progressive Collapse Design of ductile rc frame structures
Advances in Structural Engineering, 2014Co-Authors: Yi Li, Xinzheng Lu, Hong Guan, Lieping YeAbstract:Progressive Collapse is a mechanical process that exhibits nonlinear and dynamic characteristics. The nonlinear dynamic effect on the progressive Collapse resistance demand can be accurately evaluated by the nonlinear dynamic (ND) method. In engineering practice, however, the simplified and easy-to-use linear static (LS) method is often adopted. That is accomplished by using a dynamic amplification factor (DAF) to correct the LS resistance demand to approximate the true ND resistance demand. In this paper, the analytical expression of the DAF is established based on the energy conservation principle. The Collapse-resisting substructure is firstly simplified as a single-degree-of-freedom (SDOF) equivalent. Then the energy conservation equation and the static balance equation of the SDOF equivalent are established to obtain the ND and LS demands. Finally, the DAF is obtained by dividing the ND demand by the LS demand. The DAF is validated through a series of the numerical examples including a SDOF system, a...
Xinzheng Lu - One of the best experts on this subject based on the ideXlab platform.
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A novel structural detailing for the improvement of seismic and progressive Collapse performances of RC frames
Earthquake Engineering & Structural Dynamics, 2019Co-Authors: Xinzheng Lu, Yi Li, Weidong Zhuo, Hong GuanAbstract:Earthquake‐induced building Collapse and progressive Collapse due to accidental local failure of vertical components are the two most common failure modes of reinforced concrete (RC) frame structures. Conventional Design methods usually focus on the Design requirements of a specific hazard but neglect the interactions between different Designs. For example, the progressive Collapse Design of an RC frame often yields increased reinforcement and flexural strength of the beams. As a result, the seismic Design principle of “strong‐column‐weak‐beam” may be violated, which may lead to unfavorable failure modes and weaken the seismic performance. To avoid these adverse effects of the progressive Collapse Design on the seismic resistance of RC frames, a novel structural detailing is proposed in this study. The proposed detailing technique intends to concurrently improve the seismic and progressive Collapse performances of an RC frame by changing the layout of the newly added longitudinal reinforcement against progressive Collapse without introducing any additional reinforcement. A six‐story RC frame is used as the prototype building for this investigation. Both cyclic and progressive Collapse tests are conducted to validate the performance of the proposed structural detailing. Based on the experimental results, detailed finite element (FE) models of the RC frame with different reinforcement layouts are established. The seismic and progressive Collapse resistances of different models are compared based on the incremental dynamic analysis (IDA) and nonlinear dynamic alternate path (AP) methods, respectively. The results indicate that the proposed structural detailing can effectively resolve the conflict between the seismic and progressive Collapse Designs.
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Improvement to composite frame systems for seismic and progressive Collapse resistance
Engineering Structures, 2019Co-Authors: Xinzheng Lu, Lei Zhang, Yi LiAbstract:Abstract Steel-concrete composite frame is one of the widely used structural systems. Earthquake and progressive Collapse due to accidental localized damage are the main hazards that affect the safety of steel-concrete composite frames. Therefore, a seismic and progressive Collapse resistant composite frame (SPCRCF) structural system is proposed based on a comprehensive consideration of the seismic and progressive Collapse Design requirements. The seismic and progressive Collapse performances of the proposed SPCRCF were compared with the conventional steel-concrete composite frame using the experimental results of four specimens. The general-purpose finite element software, MSC.Marc, was used to simulate the specimens. The experimental and simulation results show that the proposed SPCRCF has better seismic resilience (low damage, self-centering, and easy repair) and larger progressive Collapse resistance compared to conventionally Designed steel-concrete composite frames.
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Experimental study of a novel multi-hazard resistant prefabricated concrete frame structure
Soil Dynamics and Earthquake Engineering, 2019Co-Authors: Xinzheng Lu, Yi Li, Hong GuanAbstract:Abstract Reinforced concrete (RC) frames are one of the most commonly used structural systems worldwide. Earthquake actions and progressive Collapse caused by accidental local damage are two critical hazards increasing Collapse risks of multi-story RC frames. A significant difference is well recognized between the structural seismic Design and progressive Collapse Design. Whilst the seismic Design focuses on resisting the lateral forces due to earthquake, the progressive Collapse Design deals with resisting the unbalanced vertical load induced by a localized failure. Existing research has revealed that considering the two different Designs individually for a structure may lead to an undesirable overall structural performance and unnecessary waste of construction materials. In this study, a novel Multi-Hazard Resistant, Prefabricated Concrete (MHRPC) frame system is proposed to satisfy the demands of both structural seismic and progressive Collapse Designs. Cyclic and progressive Collapse tests are conducted to validate the performance of this newly proposed structural system. The mechanisms of the MHRPC frame system under both cyclic loads and a middle column removal scenario are analyzed based on the experimental results and numerical simulations using OpenSees. The results indicate that the proposed fame system exhibits such characteristics as large rotation, low damage, self-centering, and ease of repair. The system is also proven to be able to meet the multi-hazard Design requirements of RC frames against both earthquake actions and progressive Collapse.
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Experimental Study of Novel Concrete Frames Considering Earthquake and Progressive Collapse
Concrete Structures in Earthquake, 2019Co-Authors: Xinzheng Lu, Donglian Gu, Yi LiAbstract:Earthquake and progressive Collapse are two critical hazards increasing the Collapse risks of reinforced concrete (RC) frames. Existing research has revealed that considering the seismic Design and progressive Collapse Design individually for a structure may lead to an undesirable structural performance and unnecessary waste of materials. In this study, two novel concrete frames are proposed to satisfy the demands of both seismic and progressive Collapse Designs. The experimental results of seismic cyclic and progressive Collapse tests indicate that although implementing progressive Collapse Design can effectively enhance the progressive Collapse resistance of RC frame, the beam could be over-strengthened, resulting in a potential unfavorable “strong beam-weak column” failure mode. By contrast, the novel RC frame with a newly proposed structural detailing demonstrates a minor joint region damage with a satisfying progressive Collapse resistance. Moreover, the new prefabricated frame exhibits such characteristics as large rotation, low damage, self-centering, and ease of repair.
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Effects of Seismic and Progressive Collapse Designs on the Vulnerability of RC Frame Structures
Journal of Performance of Constructed Facilities, 2017Co-Authors: Yi Li, Xinzheng Lu, Hong GuanAbstract:AbstractBuildings are exposed to multiple natural hazards over their service lives. Multihazard analysis and Design of building structures has become a research hotspot worldwide. For these structures, earthquake and progressive Collapse are two of the most commonly encountered hazards. However, little research has been conducted to examine the effects of the seismic and progressive Collapse Designs on the resistance of buildings against multiple hazards. In this study, a series of six-story reinforced concrete (RC) frames are considered, and their seismic and progressive Collapse Designs are performed independently according to the corresponding Design codes. Fragility curves are used to assess the seismic and progressive Collapse resistance. The interactions between the two Designs are discussed by analyzing the fragility curves and the Collapse modes. Results show that the progressive Collapse Design of the RC frame may lead to an undesirable failure mode (i.e., strong-beam-weak-column) under earthquak...
Kirk A Marchand - One of the best experts on this subject based on the ideXlab platform.
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dod research and criteria for the Design of buildings to resist progressive Collapse
Journal of Structural Engineering-asce, 2011Co-Authors: David Stevens, Brian Crowder, Kirk A Marchand, Eric B Williamson, Doug Sunshine, Robert Smilowitz, Mark WaggonerAbstract:The Collapse of conventional/nonhardened structures was a concern of the U.S. Department of Defense (DoD) for years before the Collapse of the World Trade Center (WTC) towers during the terrorist attacks on September 11, 2011 (9-11), owing to the bombings of the Murrah Federal Building in Oklahoma City, the U.S. embassies in Africa, and the U.S. Marine barracks in Lebanon. Since 9-11, motivated by the lack of any meaningful U.S. progressive Collapse Design requirements, DoD has worked with the civilian community on a number of significant efforts to improve the Design of buildings to resist disproportionate Collapse. The DoD efforts have included laboratory and field experiments, numerical simulations, and development of Design requirements. Synergy and coordination with the civilian community resulted in combined programs with the General Services Administration, guidance and feedback provided by the ASCE Structural Engineering Institute (SEI) Committee on Disproportionate Collapse Standards and Guidance...
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revision of the tie force and alternate path approaches in the dod progressive Collapse Design requirements
Structures Congress 2009: Don't Mess with Structural Engineers: Expanding Our Role, 2009Co-Authors: David J Stevens, Kirk A Marchand, Aldo MckayAbstract:The Department of Defense (DoD) Unified Facilities Criteria (UFC) 4-023-03 Design of Buildings to Resist Progressive Collapse was recently revised and a number of significant improvements were implemented, particularly in regards to the direct and indirect Design approaches. Direct Design explicitly considers progressive Collapse during the Design process and includes the Alternate Path method, in which the building bridges over a missing structural element, and, the Specific Local Resistance method, in which the building, or parts of the building, are Designed for a specific load or threat. In indirect Design, resistance to progressive Collapse is incorporated implicitly through prescriptive requirements for strength and continuity, typically in the form of Tie Forces, which insure a minimum tensile strength in horizontal and vertical structural members. During the revision of UFC 4-023-03, the effectiveness of the indirect and direct Design methods used in existing Design requirements was evaluated and research was performed to improve these approaches. For indirect methods, tension membrane and catenary behaviors were used to develop improved Tie Force requirements. For the Alternate Path method, the linear and nonlinear analysis procedures were improved, through adaptation of the overall approach provided in ASCE 41-06 Seismic Rehabilitation of Existing Buildings . In addition, the load and dynamic increase factors were revised, to better account for inertial and nonlinear effects in linear static and nonlinear static models. The research, analyses, and improvements for the indirect and direct methods are reported in this paper.
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Overview of the Revised DOD Progressive Collapse Design Requirements
Structures Congress 2009, 2009Co-Authors: David J Stevens, Owen Hewitt, Tim Campbell, Kirk A MarchandAbstract:In the three years since Unified Facilities Criteria (UFC) 4-023-03 Design of Buildings to Resist Progressive Collapse was first published in January of 2005, various omissions, ambiguities, and opportunities for improvement were identified by civilian and government Designers and engineers. A significant revision to the Progressive Collapse UFC was initiated in the Fall of 2006 and was recently completed, during which a number of significant improvements were made. Occupancy Categories (OCs) similar to those in ASCE 7 Minimum Design Loads for Structures are used to define a building's progressive Collapse Design requirements; previously, military definitions of levels of protection were used. Indirect Design methods for enhancing load redistribution capacity with tie forces and direct Design methods using alternate path and specific local resistance continue to be employed but with revisions. The alternate path method now includes dynamic and load increase factors that are based on careful analysis of the inertial and nonlinear aspects of load redistribution. Structural response criteria are specified in terms of force- and deformation-controlled actions, similar to ASCE 41-06 Seismic Rehabilitation of Existing Buildings . A non-threat specific, local hardening procedure was developed and implemented, to insure ductile behavior of critical elements without significant additional cost, for new construction. Finally, a brief overview of three example problems is provided.
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unified progressive Collapse Design requirements for dod and gsa
Structures Congress 2008: Crossing Borders, 2008Co-Authors: David J Stevens, Brian Crowder, Bruce Hall, Kirk A MarchandAbstract:As demonstrated in this paper, the updated UFC 4-023-03 has been significantly revised and improved relative to the initial version, to satisfy both DoD and GSA requirements. The modifications address shortcomings in the Tie Force and Alternate Path methods and result in a document that is more technically sound and rigorous, based on analysis and experimental data. The use of Occupancy Categories to determine applicability and level of Design requirements should open the combined GSA and DoD progressive Collapse Design requirements to a wider audience. Procedures outlined in the updated UFC 4-023-03 will also provide a substantial basis for prescriptive methods planned as a part of progressive Collapse mitigation approaches being developed for consensus-based, civilian building Design codes.
Mark Waggoner - One of the best experts on this subject based on the ideXlab platform.
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dod research and criteria for the Design of buildings to resist progressive Collapse
Journal of Structural Engineering-asce, 2011Co-Authors: David Stevens, Brian Crowder, Kirk A Marchand, Eric B Williamson, Doug Sunshine, Robert Smilowitz, Mark WaggonerAbstract:The Collapse of conventional/nonhardened structures was a concern of the U.S. Department of Defense (DoD) for years before the Collapse of the World Trade Center (WTC) towers during the terrorist attacks on September 11, 2011 (9-11), owing to the bombings of the Murrah Federal Building in Oklahoma City, the U.S. embassies in Africa, and the U.S. Marine barracks in Lebanon. Since 9-11, motivated by the lack of any meaningful U.S. progressive Collapse Design requirements, DoD has worked with the civilian community on a number of significant efforts to improve the Design of buildings to resist disproportionate Collapse. The DoD efforts have included laboratory and field experiments, numerical simulations, and development of Design requirements. Synergy and coordination with the civilian community resulted in combined programs with the General Services Administration, guidance and feedback provided by the ASCE Structural Engineering Institute (SEI) Committee on Disproportionate Collapse Standards and Guidance...
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discussion of examples using the revised dod progressive Collapse Design requirements
2009 Structures Congress - Don't Mess with Structural Engineers: Expanding Our Role, 2009Co-Authors: Joseph C Gannon, Walter P Moore, Viral Patel, Mark Waggoner, Eric B WilliamsonAbstract:In the three years since Unified Facilities Criteria (UFC) 4-023-03 Design of Buildings to Resist Progressive Collapse was first published in January of 2005, various omissions, ambiguities, and opportunities for improvement were identified by civilian and government Designers and engineers. A significant revision of the Progressive Collapse UFC was initiated in the fall of 2006 and was recently completed, during which a number of significant improvements were made. Readers are encouraged to refer to the newly completed document and its commentary for a discussion of revisions to the tie force procedure as well as alternate path dynamic and load increase factors, structural response criteria and other important topics. The revised Progressive Collapse UFC incorporates three example problems to demonstrate the application of the UFC requirements. This paper discusses example problems using steel, concrete, and wood structures, which illustrate the implementation of Occupancy Categories (OC) and both direct and indirect methods of providing resistance to progressive Collapse.