The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
Ying Tian - One of the best experts on this subject based on the ideXlab platform.
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experimental study of dynamic progressive collapse in flat plate buildings subjected to Exterior Column removal
Journal of Structural Engineering-asce, 2017Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:AbstractThis paper documents the findings from a dynamic collapse experiment carried out on a single-story two-by-two bay reinforced concrete flat-plate substructure. The test specimen had a 0.4 sc...
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Experimental Dynamic Response of Reinforced Concrete Flat Plate Sub-Structure under Collapse Scenario
Structures Congress 2015, 2015Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:The overall goal of this research is to evaluate the potential of disproportionate collapse in older reinforced concrete flat-plate buildings subjected to the loss of a supporting Column. If a supporting Column experiences failure, then the load must be redistributed to the surrounding connections. If the punching shear resistance of the surrounding connections is not sufficient, then a progressive collapse may result. The research program considers dynamic testing of isolated slab Column connections that represent the connection near the lost supporting Column. The dynamic tests are compared to static tests of similar specimens to determine the possible strength increase in the connection due to the loading rate. The test results show that the dynamic loading can increase the ductility of the slab by 23%, but did not show any increase in the connection strength. In addition, one multi-panel specimen representing a 0.4 scale 9 Column section of a flat slab building was dynamically tested. The specimen was loaded with dead weight equivalent to the design load 1.0D +0.5L and an Exterior Column dynamically removed. No progressive collapse occurred in the flat plate structure.
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Resistance of Flat-Plate Buildings against Progressive Collapse. II: System Response
Journal of Structural Engineering-asce, 2015Co-Authors: Ying Tian, Sarah OrtonAbstract:AbstractUsing a macromodeling approach and alternate path method, dynamic and static analyses are performed to assess the progressive collapse resistance of a multistory reinforced concrete flat-plate building lacking structural integrity reinforcement in the slabs. Two loading scenarios, instantaneous removal of an Exterior Column and interior Column, are considered. The dynamic analyses examine the potential of progressive collapse of the building, the dynamic demands on global and local nonlinear deformations, the effects of strain rate in materials, and the development of compressive membrane action. The effectiveness of an energy-based nonlinear static analysis procedure is examined for equivalently estimating the peak dynamic global and local responses caused by sudden Column removal. The analyses indicate that older flat-plate buildings are vulnerable to progressive collapse; the combined effects from strain rate and compressive membrane action can significantly increase punching resistance; energy...
Sarah Orton - One of the best experts on this subject based on the ideXlab platform.
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experimental study of dynamic progressive collapse in flat plate buildings subjected to Exterior Column removal
Journal of Structural Engineering-asce, 2017Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:AbstractThis paper documents the findings from a dynamic collapse experiment carried out on a single-story two-by-two bay reinforced concrete flat-plate substructure. The test specimen had a 0.4 sc...
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Experimental Dynamic Response of Reinforced Concrete Flat Plate Sub-Structure under Collapse Scenario
Structures Congress 2015, 2015Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:The overall goal of this research is to evaluate the potential of disproportionate collapse in older reinforced concrete flat-plate buildings subjected to the loss of a supporting Column. If a supporting Column experiences failure, then the load must be redistributed to the surrounding connections. If the punching shear resistance of the surrounding connections is not sufficient, then a progressive collapse may result. The research program considers dynamic testing of isolated slab Column connections that represent the connection near the lost supporting Column. The dynamic tests are compared to static tests of similar specimens to determine the possible strength increase in the connection due to the loading rate. The test results show that the dynamic loading can increase the ductility of the slab by 23%, but did not show any increase in the connection strength. In addition, one multi-panel specimen representing a 0.4 scale 9 Column section of a flat slab building was dynamically tested. The specimen was loaded with dead weight equivalent to the design load 1.0D +0.5L and an Exterior Column dynamically removed. No progressive collapse occurred in the flat plate structure.
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Resistance of Flat-Plate Buildings against Progressive Collapse. II: System Response
Journal of Structural Engineering-asce, 2015Co-Authors: Ying Tian, Sarah OrtonAbstract:AbstractUsing a macromodeling approach and alternate path method, dynamic and static analyses are performed to assess the progressive collapse resistance of a multistory reinforced concrete flat-plate building lacking structural integrity reinforcement in the slabs. Two loading scenarios, instantaneous removal of an Exterior Column and interior Column, are considered. The dynamic analyses examine the potential of progressive collapse of the building, the dynamic demands on global and local nonlinear deformations, the effects of strain rate in materials, and the development of compressive membrane action. The effectiveness of an energy-based nonlinear static analysis procedure is examined for equivalently estimating the peak dynamic global and local responses caused by sudden Column removal. The analyses indicate that older flat-plate buildings are vulnerable to progressive collapse; the combined effects from strain rate and compressive membrane action can significantly increase punching resistance; energy...
Zhonghua Peng - One of the best experts on this subject based on the ideXlab platform.
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experimental study of dynamic progressive collapse in flat plate buildings subjected to Exterior Column removal
Journal of Structural Engineering-asce, 2017Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:AbstractThis paper documents the findings from a dynamic collapse experiment carried out on a single-story two-by-two bay reinforced concrete flat-plate substructure. The test specimen had a 0.4 sc...
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Experimental Dynamic Response of Reinforced Concrete Flat Plate Sub-Structure under Collapse Scenario
Structures Congress 2015, 2015Co-Authors: Zhonghua Peng, Sarah Orton, Ying TianAbstract:The overall goal of this research is to evaluate the potential of disproportionate collapse in older reinforced concrete flat-plate buildings subjected to the loss of a supporting Column. If a supporting Column experiences failure, then the load must be redistributed to the surrounding connections. If the punching shear resistance of the surrounding connections is not sufficient, then a progressive collapse may result. The research program considers dynamic testing of isolated slab Column connections that represent the connection near the lost supporting Column. The dynamic tests are compared to static tests of similar specimens to determine the possible strength increase in the connection due to the loading rate. The test results show that the dynamic loading can increase the ductility of the slab by 23%, but did not show any increase in the connection strength. In addition, one multi-panel specimen representing a 0.4 scale 9 Column section of a flat slab building was dynamically tested. The specimen was loaded with dead weight equivalent to the design load 1.0D +0.5L and an Exterior Column dynamically removed. No progressive collapse occurred in the flat plate structure.
Mehrdad Sasani - One of the best experts on this subject based on the ideXlab platform.
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Integrity and progressive collapse resistance of RC structures with ordinary and special moment frames
Engineering Structures, 2015Co-Authors: Menglu Li, Mehrdad SasaniAbstract:Abstract General building codes and standards include structural integrity requirements as an indirect approach to mitigate the likelihood of collapse of structures due to abnormal loading conditions. Structures are designed for load combinations including live, dead, wind, earthquake, and other loads. Particularly for earthquake loads, different design approaches are used with the general understanding that for sites with high seismicity, structures need to be ductile and in turn may be designed for relatively smaller base shear. In this paper the effects of seismic design and structural integrity requirements on progressive collapse resistance of reinforced concrete frame structures is evaluated. The relative importance of ductility (deformation) capacity and strength is discussed for response of structures subjected to severe seismic ground motions and to loss of a Column. The effects of span length on a building’s response after Column removal are discussed. It is demonstrated that for buildings with shorter spans at sites with low to medium seismic severity, designing for higher seismicity does not necessarily lead to a better performance and smaller vertical displacement following loss of an Exterior Column. Effects of other parameters, such as the joist torsional stiffness and concrete tensile strength are also discussed. An approximate method using equivalent single degree of freedom systems is presented for evaluating maximum displacement response of structures after element failure, which estimated the building responses studied in this paper with a maximum error of 13%.
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Progressive collapse evaluation of Murrah Federal Building following sudden loss of Column G20
Engineering Structures, 2015Co-Authors: Ali Kazemi-moghaddam, Mehrdad SasaniAbstract:Abstract The Murrah Federal Building (MFB) was the main target of the Oklahoma City Bombing in 1995. Previous studies have concluded that the building would have collapsed even if Exterior Column G20 was statically removed. In this paper, the system-level response of the MFB due to the sudden loss of Column G20 is analytically studied. It is demonstrated that the building would have resisted progressive collapse, even if the Column was suddenly removed. Two important reasons have led to a different conclusion from those of the previous studies. First, the axial compressive force of the Column above the lost Column diminishes only a few milliseconds after Column removal, thus, it does not continue to push the supporting girder down. Second, two collapse resisting mechanisms were not considered in the previous studies: (a) a beam’s tendency to grow as it cracks and yields under flexure and its effects on the axial–flexural response of the 3rd floor transfer girder, resulting in the enhancement of its gravity load carrying capacity and (b) the redistribution of the gravity loads through new load paths in both longitudinal and transverse directions through Vierendeel frame action. Given that the structure collapsed, the initial damage to the MFB must have been more severe than a sudden loss of Column G20.
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Experimental and Analytical Progressive Collapse Evaluation of Actual Reinforced Concrete Structure
Aci Structural Journal, 2007Co-Authors: Mehrdad Sasani, Marlon Bazan, Serkan SagirogluAbstract:One approach to evaluate progressive collapse of structures is to study the effects of instantaneous removal of a load-bearing element such as a Column. In this paper, using experimental and analytical results, potential progressive collapse of an actual 10-story reinforced concrete (RC) structure following the explosion of an Exterior Column is evaluated. Development of Vierendeel action is identified as the dominant mechanism in redistribution of loads in this structure. The concrete modulus of rupture is identified as an important parameter in limiting the maximum recorded vertical deformation of the system to only 0.25 in. (6.4 mm). The changes in the directions of bending moments in the vicinity of the removed Column and their effects such as potential reinforcing bar pullout (bond failure) are studied. Potential failure modes and their consequences are studied. Some shortcomings of integrity requirements in current codes are pointed out and effects of beam reinforcement detail on the development of catenary action are discussed.
H.h. Snijder - One of the best experts on this subject based on the ideXlab platform.
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Preliminary design of outrigger braced shear wall structures on flexible foundations
2020Co-Authors: J.c.d. Hoenderkamp, M.c.m. Bakker, H.h. SnijderAbstract:This paper presents a graphical method to optimise the position of outriggers on shear walls with flexible foundations. This location for the outriggers will cause a maximum reduction in lateral deflection at the top of the building. The method can be used for preliminary design of high-rise structures subjected to horizontal loading. The method requires the calculation of six structural parameters: bending stiffnesses for the shear wall and outrigger structure, an overall bending stiffness contribution from the Exterior Columns, rotational stiffnesses for the shear wall and Column foundations in addition to a newly suggested bending stiffness parameter representing the structural behaviour of the flexible foundation beam connecting the foundation of the shear wall to the Exterior Column foundations. These parameters allow the derivation of two compatibility equations for rotations at the intersections of the neutral lines of the shear wall with the outrigger and foundation structures. They yield expressions for the restraining moments at outrigger and foundation levels that act in the opposing direction to the bending moment from the horizontal loading on the structure. Maximising the influence of the restraining moments on the horizontal deflections leads to the optimum location of the outrigger structure. Combining all stiffness parameters into two non-dimensional characteristic structural parameters allows the optimisation procedure for this type of structure to be represented by a single graph that directly gives the optimum level of the outrigger. It is concluded that all six stiffness parameters need to be included in the preliminary analysis of a proposed tall building structure as the optimum location of the outrigger as well as the reductions in horizontal deformations and internal forces in the structure can be significantly influenced by all the structural components.
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Preliminary design of high-rise outrigger braced shear wall structures on flexible foundations
2003Co-Authors: J.c.d. Hoenderkamp, M.c.m. Bakker, H.h. SnijderAbstract:This paper presents a graphical method to optimise the position of outriggers on shear walls with flexible foundations. This location for the outriggers will cause a maximum reduction in lateral deflection at the top of the building. The method can be used for preliminary design of high-rise structures subjected to horizontal loading. The method requires the calculation of six structural parameters: bending stiffnesses for the shear wall and outrigger structure, an overall bending stiffness contribution from the Exterior Columns, rotational stiffnesses for the shear wall and Column foundations in addition to a newly suggested bending stiffness parameter representing the structural behaviour of the flexible foundation beam connecting the foundation of the shear wall to the Exterior Column foundations. These parameters allow the derivation of two compatibility equations for rotations at the intersections of the neutral lines of the shear wall with the outrigger and foundation structures. They yield expressions for the restraining moments at outrigger and foundation levels that act in the opposing direction to the bending moment from the horizontal loading on the structure. Maximising the influence of the restraining moments on the horizontal deflections leads to the optimum location of the outrigger structure. Combining all stiffness parameters into two non-dimensional characteristic structural parameters allows the optimisation procedure for this type of structure to be represented by a single graph that directly gives the optimum level of the outrigger. It is concluded that all six stiffness parameters need to be included in the preliminary analysis of a proposed tall building structure as the optimum location of the outrigger as well as the reductions in horizontal deformations and internal forces in the structure can be significantly influenced by all the structural components.
