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Claudio Modena - One of the best experts on this subject based on the ideXlab platform.
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simplified seismic assessment of railway masonry Arch Bridges by limit analysis
Structure and Infrastructure Engineering, 2016Co-Authors: Francesca Da Porto, Paolo Zampieri, Claudio Modena, Giovanni Tecchio, Andrea ProtaAbstract:In this work, the seismic capacity of single and multi-span masonry Arch Bridges was assessed by limit analysis. A preliminary statistical survey was carried out on a stock of about 750 railway Bridges in Italy, classified according to characteristics and expected collapse mechanisms under seismic excitation. A comprehensive parametric study was carried out on identified homogeneous classes, to calculate limit horizontal accelerations triggering the collapse mechanism in longitudinal and transverse directions. Iso-acceleration envelope curves, representing limit horizontal acceleration of the bridge as a function of geometric parameters, were then derived. These graphs can be used for preliminary seismic safety checking of existing masonry Bridges, once the main geometric parameters are available by simple visual inspections and geometric surveys, and can easily be implemented in a Bridge Management System to prioritise seismic retrofitting interventions.
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simplified seismic assessment of multi span masonry Arch Bridges
Bulletin of Earthquake Engineering, 2015Co-Authors: Paolo Zampieri, Mariano Angelo Zanini, Claudio ModenaAbstract:The paper describes a simplified methodology for the evaluation of the seismic retrofit intervention types to be performed on clusters of multi-span masonry Arch Bridges, on the basis of the main Bridges geometrical characteristics. The structural behaviour of the analysed sample Bridges has been evaluated in their principal directions highlighting the potential local and global vulnerabilities and the related retrofit intervention typologies that need to be selected. The main aim of this study is to take the form of an useful tool for identify the best retrofit strategies for each masonry bridge structure in function of its geometrical characteristics and thus planning rationally the management of Bridges belonging to rail and road networks.
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performance evaluation of short span reinforced concrete Arch Bridges
Journal of Bridge Engineering, 2004Co-Authors: Giovanna Zanardo, Carlo Pellegrino, Carlo Bobisut, Claudio ModenaAbstract:In this paper, the static and seismic performance of some short span reinforced concrete Arch Bridges, before and after strengthening interventions, are evaluated. To verify whether retrofit strategies for the considered Arch Bridges, which were designed for resisting under permanent and service actions, were adequate for earthquake resistance, seismic analyses of the as-built model of the structures have been undertaken. To account for multiple input effects on Arches, induced by out-of-phase motions at foundation levels as well as different boundary conditions at structural supports, the seismic response of the structures under correlated horizontal and vertical multiple excitations is calculated. The effects on Arch Bridges of conventionally used uniform input and partially correlated multiple inputs with phase shifts are compared. In all cases, the results are discussed with particular reference to the influence of structural configuration, secondary systems, cross-section thickness of the Arch, and retrofit interventions.
Hanbin Ge - One of the best experts on this subject based on the ideXlab platform.
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a seismic upgrading method for steel Arch Bridges using buckling restrained braces
Earthquake Engineering & Structural Dynamics, 2005Co-Authors: Tsutomu Usami, Zhihao Lu, Hanbin GeAbstract:In this study the employment of buckling-restrained braces (BRBs) as energy dissipation dampers is attempted for seismic performance upgrading of steel Arch Bridges and the effectiveness of BRBs to protect structures against strong earthquakes is numerically studied. With buckling restrained, BRB members can provide stable energy dissipation capacity and thus damage of the whole structure under major earthquakes can be mitigated. Cyclic behaviour of such members is addressed with a numerical simulation model, and a strength design method for BRBs is proposed. BRBs are then placed at certain locations on the example steel Arch bridge to replace some normal members with two schemes, and the effect of the two installation schemes of BRBs for seismic upgrading is investigated by non-linear time-history analyses under various ground motions representing major earthquake events. Compared with the seismic behaviour of the original structure without BRBs, satisfactory seismic performance is seen in the upgraded models, which clarifies the effectiveness of the proposed upgrading method and it can serve as an efficient solution for earthquake-resistant new designs and retrofit of existing steel Arch Bridges. Copyright © 2005 John Wiley & Sons, Ltd.
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seismic performance evaluation of steel Arch Bridges against major earthquakes part 2 simplified verification procedure
Earthquake Engineering & Structural Dynamics, 2004Co-Authors: Zhihao Lu, Tsutomu Usami, Hanbin GeAbstract:The performance-based philosophy has been accepted as a more reasonable design concept for engineering structures. For this purpose, capacity evaluation and demand prediction procedures for civil engineering structures under earthquake excitations are of great significance. This work presents a displacement-based seismic performance verification procedure including capacity and seismic demand predictions for steel Arch Bridges and investigates its applicability. Pushover analyses is employed as a basis in this method to investigate the structure's behaviors. A failure criterion for steel members accounting for the effect of local buckling is involved and an equivalent single-degree-of-freedom (ESDOF) system with a simplified bilinear hysteretic model formulated using pushover analyses results is introduced to estimate the displacement capacity and maximum demand of steel Arch Bridges under major earthquakes. To check the accuracy of the proposed method, seismic capacities and demands from multi-degree-of-freedom (MDOF) time-history analyses with Level-II design earthquake record inputs modeling major earthquakes are used as benchmarks for comparison. By a case study, it is clarified that the proposed prediction procedure can give accurate estimations of displacement capacities and demands of the steel Arch bridge in the transverse direction, while insufficient for the longitudinal direction, which confirms the conclusion drawn in other structure types about the applicability of pushover analyses.
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applicability of pushover analysis based seismic performance evaluation procedure for steel Arch Bridges
Engineering Structures, 2004Co-Authors: Zhihao Lu, Hanbin Ge, Tsutomu UsamiAbstract:An investigation on the application of a capacity and demand prediction procedure based on a nonlinear pushover analysis and an equivalent single-degree-of-freedom (ESDOF) system approximation for seismic performance evaluation of steel Arch Bridges, as well as limitations of the pushover analysis is presented here. The procedure is applied to the transverse direction of two representative Arch Bridges with different spans for capacity and demand estimation. Displacement capacities are obtained by conducting pushover analysis until the ultimate state of the structure is reached, determined by a failure criterion proposed for thin-walled steel members governed by the local buckling-induced failure. Displacement demands under major earthquakes are estimated by ESDOF systems formulated using pushover analysis results. Capacities and demands are then compared with those from rigorous nonlinear time–history analyses on multi-degree-of-freedom (MDOF) models for verification and acceptable accuracy of the pushover analysis-based procedure is evidenced. Furthermore, applicability of the pushover analysis involving the fundamental mode only for seismic performance evaluation is extensively investigated considering the higher mode effect. A factor to account for higher mode contribution to seismic response is proposed and an applicable range of using the pushover analysis is quantitatively specified.
Mohammad S Marefat - One of the best experts on this subject based on the ideXlab platform.
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seismic performance assessment of plain concrete Arch Bridges under near field earthquakes using incremental dynamic analysis
Engineering Failure Analysis, 2019Co-Authors: Mahdi Yazdani, V Jahdngiri, Mohammad S MarefatAbstract:Abstract In the railway network of Iran, a large number of masonry Arch Bridges exist which most of them was constructed 80 years ago. Despite these types of Bridges have shown an appropriate behavior under the influence of gravity (vertical) loads, they have not been designed seismically. Concerning to the seismic hazard zoning map of Iran, most of these railway infrastructures are placed in the very high seismicity zones and constructed near the major faults. So the seismic assessment of these types of Bridges has become a significant subject for the engineers to explain the failure and seismic performance levels of these structures. Thus, they can be rehabilitated or removed if it is found required. Among various methods for seismic estimation of the capacity of the structures under seismic loading, the non-linear dynamic method or the incremental dynamic analysis (IDA) may be mentioned as the most precise and complete method for near-field excitations. For this purpose, by selecting 28 near-field earthquake records, this study has seismically surveyed two railway masonry Arch Bridges, which are respectively placed in the kilometers 23 (2L20 bridge) and 24 (5L06 bridge) of the old railway of Tehran-Qom. The macro-modeling approach was used in the finite element method. In total, 316 non-linear dynamic analyses have been carried out for the seismic assessment of the masonry Arch Bridges under near-field ground motion. The results found from the IDA analysis specified that the near-field seismic performance of the masonry Arch bridge with lower span length (i.e., 5L06 bridge) is safer than the bridge with longer span length (i.e., 2L20 bridge). Mostly, it has to decide to retrofit the masonry bridge with longer span length to improve their performance since the seismic behavior of those has been found inappropriate under near-field earthquakes.
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intensity measures for the seismic response assessment of plain concrete Arch Bridges
Bulletin of Earthquake Engineering, 2018Co-Authors: Vahid Jahangiri, Mahdi Yazdani, Mohammad S MarefatAbstract:Intensity measures (IMs) are used as a link between seismic hazard and seismic demand analysis and therefore have a key role in performance-based earthquake engineering. To the best of our knowledge, no study has been carried out on the determination of suitable IMs to evaluate the seismic demand of plain concrete Arch Bridges. In the present study, the efficiency, sufficiency, scaling robustness and practicality of 34 potential IMs for evaluating the seismic response of two old railway plain concrete Arch Bridges in km-23 and km-24 of Tehran–Qom railway are investigated. The considered Bridges are simulated using finite-element method and subjected to incremental dynamic analysis (IDA) using 22 far-field earthquake ground motion records. Complete response of the models is obtained through IDA method in terms of engineering demand parameter measured by the maximum displacement of the Bridges. The optimal IMs among the considered intensity measures for evaluating seismic demand of the investigated plain concrete Arch Bridges are recognized using the concepts of efficiency, sufficiency, scaling robustness and practicality. Using the results of the regression analysis, it is concluded that root mean square acceleration is the optimal IM based on efficiency, sufficiency, scaling robustness and practicality for seismic response evaluation of plain concrete Arch Bridges under far-field ground motions.
Paolo Zampieri - One of the best experts on this subject based on the ideXlab platform.
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Lateral Stability of Network Arch Bridges
Structural Integrity, 2019Co-Authors: Cyrille Denis Tetougueni, Paolo Zampieri, Carlo PellegrinoAbstract:Network Arch Bridges are Arch Bridges where hangers intersect each other at least twice. Although these innovative Bridges present several advantages in terms of cost and structural performance with respect to the conventional tied-Arch Bridges, they remain vulnerable under certain loading condition. Indeed, due to the large compressive force that may arise in steel Arches of the bridge under service, they are prone to deflect out of his plane resulting in the degradation of the aesthetic aspect often praised of Bridges of this type and later its service disablement. For this reason, the lateral behaviour of such kind of Bridges should be investigated carefully. In this study, lateral structural response of network Arch Bridges against traffic loads has been analyzed through extensive non-linear analyses. Firstly, a calibration is useful to validate the numerical model. Then, initial geometric imperfections are assigned to the Arch member before the analysis in order to take into consideration defects from the manufacturing process. Finally, non-linear analyses are performed on a full 3D numerical model to capture the behaviour of the Arch bridge. The results showed that the lateral displacement of the Arch member increase with the increase of the traffic loads up to a certain value. In addition, it is observed that the lateral Arch’s bracing changes the development of plastic hinges in the Arch.
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failure analysis of masonry Arch Bridges subject to local pier scour
Engineering Failure Analysis, 2017Co-Authors: Paolo Zampieri, Lorenzo Hofer, Flora Faleschini, Mariano Angelo Zanini, Carlo PellegrinoAbstract:Abstract In European roadway and railway networks, many multi-span unreinforced Arch Bridges were built in the last century. These structures are often characterized by piers with shallow foundations placed in the riverbed, which can be subject to hydrodynamic turbulences in case of river floods and further localized scour phenomena. The lack of adequate monitoring can cause scour-induced settlements over time, potentially causing bridge structural failure. This work investigates the structural behavior of existing masonry Bridges subject to local pier scour. A case study is used to carry out the failure analysis, simulating the evolution of the structural behavior of a six-span masonry Arch bridge with a finite element model, correlated with the local scour profile.
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simplified seismic assessment of railway masonry Arch Bridges by limit analysis
Structure and Infrastructure Engineering, 2016Co-Authors: Francesca Da Porto, Paolo Zampieri, Claudio Modena, Giovanni Tecchio, Andrea ProtaAbstract:In this work, the seismic capacity of single and multi-span masonry Arch Bridges was assessed by limit analysis. A preliminary statistical survey was carried out on a stock of about 750 railway Bridges in Italy, classified according to characteristics and expected collapse mechanisms under seismic excitation. A comprehensive parametric study was carried out on identified homogeneous classes, to calculate limit horizontal accelerations triggering the collapse mechanism in longitudinal and transverse directions. Iso-acceleration envelope curves, representing limit horizontal acceleration of the bridge as a function of geometric parameters, were then derived. These graphs can be used for preliminary seismic safety checking of existing masonry Bridges, once the main geometric parameters are available by simple visual inspections and geometric surveys, and can easily be implemented in a Bridge Management System to prioritise seismic retrofitting interventions.
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simplified seismic assessment of multi span masonry Arch Bridges
Bulletin of Earthquake Engineering, 2015Co-Authors: Paolo Zampieri, Mariano Angelo Zanini, Claudio ModenaAbstract:The paper describes a simplified methodology for the evaluation of the seismic retrofit intervention types to be performed on clusters of multi-span masonry Arch Bridges, on the basis of the main Bridges geometrical characteristics. The structural behaviour of the analysed sample Bridges has been evaluated in their principal directions highlighting the potential local and global vulnerabilities and the related retrofit intervention typologies that need to be selected. The main aim of this study is to take the form of an useful tool for identify the best retrofit strategies for each masonry bridge structure in function of its geometrical characteristics and thus planning rationally the management of Bridges belonging to rail and road networks.
T E Boothby - One of the best experts on this subject based on the ideXlab platform.
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load rating of masonry Arch Bridges refinements
Journal of Bridge Engineering, 2004Co-Authors: T E Boothby, Paul J FanningAbstract:In a paper previously published by the first writer, a procedure for load-rating masonry Arch Bridges was introduced. The procedure uses the Load Factor Method of the 1994 American Association of State Highway and Transportation Officials \IManual for the Condition Evaluation of Bridges\N, applied to a frame analysis model of a masonry Arch spanning from abutment to abutment. The procedure is based on the assumption of the Arch barrel having no tensile strength. The objective of this technical note is to complement the initial procedure by enabling the assessing engineer to exercise discretion in deciding whether or not a small value of tensile strength should be allowable in determining a suitable rating for masonry Arch Bridges. In addition the initially proposed strength values, which are considered overly conservative, are increased. The introduction of these refinements will allow a more accurate assessment of the nation’s stock of stone masonry Bridges.
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three dimensional modelling and full scale testing of stone Arch Bridges
Computers & Structures, 2001Co-Authors: Paul J Fanning, T E BoothbyAbstract:Abstract Existing test results of full-scale in-service masonry Arch Bridges are analysed to determine appropriate material properties for the modelling of this structural type. Three-dimensional nonlinear finite element models of three masonry Arch Bridges are generated using a commercially available finite element package. The behaviour of the masonry is replicated by use of a solid element that can have its stiffness modified by the development of cracks and crushing. The fill is modelled as a Drucker–Prager material, and the interface between the masonry and the fill is characterised as a frictional contact surface. The Bridges are modelled under service loads, and the model results are compared to the results of a program of field testing of the structures. It is found that the assumption of a reasonable set of material properties, based on visual observations of the material and construction of the structure, implemented through a program of three-dimensional nonlinear finite element analysis enable good predictions of the actual behaviour of a masonry Arch bridge.
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Transverse behaviour of masonry Arch Bridges
The Structural engineer, 2001Co-Authors: T E Boothby, B. J. RobertsAbstract:ReseArch efforts in the assessment of masonry Arch Bridges have concentrated on the strength of the Arch in the span direction. However, experience with these structures indicates that masonry Arch Bridges more often fail by sliding or overturning of the spandrel walls perpendicular to the roadway centreline, or by the development of longitudinal cracks in the Arch barrel and eventual separation of the spandrels from the remainder of the Arch barrel. The present paper reports results of a 3-dimensional non-linear finite element (FE) model of an Arch bridge that uses a Drucker-Prager material for the fill and a brittle material for the masonry. The model predicts that most truck-loaded stone Arch Bridges will exhibit a premature failure due to lateral effects rather than a mechanism collapse. The predicted lateral failure modes include local spandrel wall failures, overturning of the spandrel walls, edge failure of the Arch barrel, and local punching of the Arch. Stone Bridges with thin Arches or Bridges with very low tensile strengths were predicted to be significantly weakened by such lateral effects. (A)
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DYNAMIC TESTING OF MASONRY Arch Bridges
1998Co-Authors: J W Bintrim, J A Laman, T E BoothbyAbstract:This study examines the dynamic testing of masonry Arch Bridges to determine structural condition. Three masonry Arch Bridges were tested using seismometers and LVDTs to measure the responses. The Bridges were loaded using calibration trucks, random traffic, and a drop-weight device. The use of vibration velocities, intensities, and frequencies were used to determine the condition of the Bridges. The vibration studies are simple to conduct, but the longitudinal crack present in the Stony Brook Bridge was undetected by the vibration testing. The other two structures showed very large vibrations in a structure with no visible damage. These vibrations could indicate large cracks in the structure causing a separation of the Arch ring. This shows the promise of using vibration testing to determine the position of localized damage in less complex masonry Arch Bridges. (A) For the covering abstract, see IRRD E100543.
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service load response of masonry Arch Bridges
Journal of Structural Engineering-asce, 1998Co-Authors: T E Boothby, Daniel E Domalik, Vikram A DalalAbstract:The behavior of filled masonry Arch Bridges under truck loading is examined by service load testing and by developing a finite-element model of a unit width of the structure. The field tests included five structures varying in span from 3 to 12 m. The structures tested included a group of three structures of similar geometry, material, age, and geographic location. The testing program demonstrated the significance of the linearity of the response to different loading levels and the importance of permanent deformations in evaluating a structure. The field tests also gave evidence of the range of responses of similar structures, and showed some evidence of the development of an incipient mechanism. The analytical model included approximation of the load distribution through the fill and the restraint to movements of the Arch ring developed by the fill and spandrel walls. Reasonable approximations of the experimentally observed response of the structures were obtained using the analytical model. Guidance in ...
