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Eric Sumner - One of the best experts on this subject based on the ideXlab platform.
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proposed design guidelines for strengthening of Steel Bridges with frp materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:Abstract This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel–concrete composite bridge girders. The flexural design procedure is based on a moment–curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness.
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Proposed design guidelines for strengthening of Steel Bridges with FRP materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel-concrete composite bridge girders. The flexural design procedure is based on a moment-curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness. © 2006 Elsevier Ltd. All rights reserved.
Michel Bruneau - One of the best experts on this subject based on the ideXlab platform.
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ductile end diaphragms for seismic retrofit of slab on girder Steel Bridges
Journal of Structural Engineering-asce, 1999Co-Authors: Seyed Mehdi Zahrai, Michel BruneauAbstract:Steel Bridges are frequently supported by seismically vulnerable substructures, as clearly dem- onstrated by recent earthquakes. The seismic retrofit of these nonductile substructures can be, in many cases, a rather costly operation. This paper investigates the adequacy of a seismic retrofit strategy that relies instead on ductile end-diaphragms inserted in the Steel superstructure: the objective is to protect the substructure by re- placing the Steel diaphragms over abutments and piers with specially designed ductile diaphragms calibrated to yield before the strength of the substructure is reached. For a type of Steel slab-on-girder bridge widely found in North America, this paper presents simplified analytical models as well as a step-by-step design procedure developed for three types of ductile diaphragm systems (such as shear panels, eccentrically braced frames, and triangular-plate added damping and stiffness devices), followed by results from nonlinear inelastic analyses conducted to investigate the seismic behavior of these retrofitted Bridges. At this time, only Bridges on stiff substructure are considered, although a few examples are presented to illustrate the potential inadequacy of this retrofit approach for Bridges on flexible substructures.
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impact of diaphragms on seismic response of straight slab on girder Steel Bridges
Journal of Structural Engineering-asce, 1998Co-Authors: Seyed Mehdi Zahrai, Michel BruneauAbstract:Many Steel Bridges have suffered diaphragm (cross frame) damage during recent earthquakes. Diaphragms provide an important load path for the seismically induced loads acting on slab-on-girder Steel Bridges, but their impact on seismic response is still unclear in many ways. The relative role played by intermediate and end diaphragms in providing lateral load resistance, along with the consequences of diaphragm damage on bridge seismic response, has not been studied. This paper quantitatively investigates the impact of diaphragms on the seismic response of straight slab-on-girder Steel Bridges. Typical 20 to 60 m span slab-on-girder Bridges with and without diaphragms are considered and studied through elastic and inelastic static push-over analyses. Two hand-calculation analytical models are proposed to evaluate their period, elastic response, and pseudospectral acceleration at first yielding. It is shown that a small end-diaphragm stiffness is sufficient to make the entire superstructure behave as a unit...
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performance of Steel Bridges during the 1995 hyogo ken nanbu kobe japan earthquake
Canadian Journal of Civil Engineering, 1996Co-Authors: Michel Bruneau, John C Wilson, Robert TremblayAbstract:A large number of Steel Bridges were damaged by the January 17, 1995, Hyogo-ken Nanbu (Kobe, Japan) earthquake. The concentration of Steel Bridges in the area of severe shaking was considerably larger than for any previous earthquake this century. As a result, this earthquake has provided a unique opportunity to examine how Steel Bridges of various designs and configurations behave when subjected to severe ground shaking. In this paper, a description of the Japanese past and current bridge design requirements is first presented, followed by an in-depth overview of the observed damage to Steel Bridges. The relevance of these observations to the Canadian bridge design practice is also reviewed. Key words: earthquake, seismic, Steel, Bridges, Steel columns, buckling, brittle fractures, bearing failures, seismic restrainers, design codes.
David Schnerch - One of the best experts on this subject based on the ideXlab platform.
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proposed design guidelines for strengthening of Steel Bridges with frp materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:Abstract This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel–concrete composite bridge girders. The flexural design procedure is based on a moment–curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness.
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Proposed design guidelines for strengthening of Steel Bridges with FRP materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel-concrete composite bridge girders. The flexural design procedure is based on a moment-curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness. © 2006 Elsevier Ltd. All rights reserved.
Mina Dawood - One of the best experts on this subject based on the ideXlab platform.
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proposed design guidelines for strengthening of Steel Bridges with frp materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:Abstract This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel–concrete composite bridge girders. The flexural design procedure is based on a moment–curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness.
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Proposed design guidelines for strengthening of Steel Bridges with FRP materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel-concrete composite bridge girders. The flexural design procedure is based on a moment-curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness. © 2006 Elsevier Ltd. All rights reserved.
Sami Rizkalla - One of the best experts on this subject based on the ideXlab platform.
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proposed design guidelines for strengthening of Steel Bridges with frp materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:Abstract This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel–concrete composite bridge girders. The flexural design procedure is based on a moment–curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness.
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Proposed design guidelines for strengthening of Steel Bridges with FRP materials
Construction and Building Materials, 2007Co-Authors: David Schnerch, Sami Rizkalla, Mina Dawood, Eric SumnerAbstract:This paper focuses on the use of externally bonded high modulus carbon fiber reinforced polymer (HM CFRP) materials to strengthen Steel Bridges and structures. Proper installation of the CFRP materials is necessary to prevent premature failure due to debonding. The paper proposes guidelines and installation techniques based on the best practice reported in the literature and the extensive practical experience in bonding of composite materials. The surface preparation of the materials, the application of the adhesive and the detailing of the strengthening are provided in detail. The design guidelines include the structural design criteria for the use of high modulus CFRP materials as flexural strengthening system of typical Steel-concrete composite bridge girders. The flexural design procedure is based on a moment-curvature analysis and a specified increase of the live load carried by the bridge to satisfy specific serviceability requirements. A bond model is also described which can be used to calculate the shear and peel stresses within the adhesive thickness. To prevent a premature debonding failure of the strengthening system, the criteria specify a maximum principle stress in the adhesive which cannot be exceeded for a given characteristic strength of an adhesive. A worked example is presented to illustrate the proposed flexural design approach. The research findings conclude that high modulus CFRP materials provide a promising alternative for strengthening Steel Bridges that can be easily designed and installed to increase their strength and stiffness. © 2006 Elsevier Ltd. All rights reserved.
