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Effect of seismic retrofit of bridges on transportation networks

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Earthquake Engineering and Engineering Vibration 2003年第2期2卷 169-179页

作者： Masanobu Shinozuka Yuko Murachi Michal J.Orlikowski Department of Civil and Environmental Engineering University of CaliforniaIrvineUSA Distinguished Professor and Chair Department of Civil and Environmental Engineering University of CaliforniaIrvineUSA Research Associate Department of Civil and Environmental Engineering Princeton UniversityUSA Undergraduate Student.

The objective of this research is to determine the effect earthquakes have on the performance of transportation network *** do this,bridge fragility curves,expressed as a function of peak ground acceleration(PGA)and peak ground velocity(PGV),were *** damage was evaluated under the 1994 Northridge earthquake and scenario earthquakes.A probabilistic model was developed to determine the effect of repair of bridge damage on the improvement of the network performance as days passed after the *** an example,the system performance degradation measured in terms of an index,'Drivers Delay,'is calculated for the Los Angeles area transportation system,and losses due to Drivers Delay with and without retrofit were estimated.

关键词： fragility curves seismic retrofit probabilistic model bridges transportation networks drivers delay performance index Northridge earthquake.

Behaviour and Analysis of Horizontally Curved Steel Box-Girder bridges

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Open Journal of Civil Engineering 2022年第3期12卷 390-414页

作者： Mattia Mairone Rebecca Asso Davide Masera Pietro Palumbo Research and Development Masera Engineering Group S.r.l Corso Re Umberto 8 Torino Italy Department of Structural Geotechnical and Building Engineering DISEG Politecnico di Torino Corso Duca degli Abruzzi 24 Torino Italy Masera Engineering Group S.r.l. Corso Re Umberto 8 Torino Italy

Various theories and analytical formulations were implemented and exploited in the 1980s and 1990s for the design of bridge beams or decks curved in the horizontal plane and subjected to out-of-plane loads. Nowadays, the Finite Element Method (FEM) is a valid tool for the analysis of structures with complex geometries and, therefore, the development of sophisticated analytical formulations is not needed anymore. However, they are still useful for the validation of FE models. This paper presents the case study of an existing viaduct built in North Italy, aiming to compare analytical approaches and numerical modelling. The bridge is characterized by an axis curved in two directions and a rectilinear segment. The global analysis of the viaduct is carried out with special attention to the attributes that cause torque action and bending moment. The theoretical developments focus on a deeper understanding of the torsional response under different constraint and loading conditions and aspire to raise awareness of the mutual interaction of flexural and torsional behaviour, that are always present in these complex curved systems. The examination of the case study is also obtained by comparing the response of isostatic and hyperstatic curvilinear steel box-girders.

关键词： Analytical Calculation bridges Horizontally Curved Beam Structural Response Torsion

The Song of the River:The Hidden Beautyof Old Covered bridges

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中国新书:英文版 2023年第2期 22-29页

作者： Zhou Huacheng the China Writers Association

This book tells the stories of ancient covered bridges in southern Zhejiang,with a cultural prose *** presents the spiritual connotation behind the covered bridge culture with quiet and profound language and shows readers the strong spiritual support brought by this ancient *** author spent more than two years searching for Taishun Covered *** integrated documentary into pure literature and expressed the rich connotation of the covered bridge as Zhejiang's cultural business card with enchanting literarylanguage.

关键词： bridges searching spirit

The Values and Significance of the Colonial Steel Railway bridges of Pakistan

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Built Heritage 2017年第4期1卷 11-21页

作者： Ayesha Pamela Rogers Ghulam Mustafa Baloch Cultural Studies Department National College of ArtsLahorePakistan

This paper proposes that Civil Engineering Heritage is a distinct form of heritage,related to but differing from Industrial Heritage and a separate field that should be treated *** critical element that signifies engineering heritage is ingenium or innovation in development of complex technological responses to physical *** heritage requires specific approaches to its identification,documentation,conservation and *** important first step of this process is a clear understanding of the values and attributes that contribute to the significance of engineering heritage and must be *** example of engineering heritage examined here is the colonial steel railway bridges of Pakistan;three case study bridges are presented and the values and attributes of each are *** paper then identifies a set of shared essential values of this type of engineering heritage that can serve as a basis for value-based conservation and management.

关键词： civil engineering heritage bridges colonial Pakistan values innovation

Asynchronous earthquake strong motion and RC bridges response

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Journal of Traffic and Transportation Engineering(English Edition) 2018年第6期5卷 454-466页

作者： Davide Lavorato Gabriele Fiorentino Alessandro Vittorio Bergami Bruno Briseghella Camillo Nuti Silvia Santini Ivo Vanzi Department of Architecture Roma Tre University College of Civil Engineering Fuzhou University Department of Engineering and Geology University of Chieti-Pescara "G.d'Annunzio"

The dynamic response of long structures(e.g., bridges) is sensitive to the spatial variability of strong ground motion(asynchronous motion). Ground motion differences increase from point to point with increasing foundation distance. This latter is due to two physical phenomena: soil-wave interaction, that causes the loss of coherence and local amplification; wave traveling with finite velocity, that causes signals time lag. This ground motion variability produces a different structural demand compared to the synchronous one,which is the only one considered by designers in the majority of cases. A few codes consider this type of actions, therefore further research efforts are necessary. In this study,asynchronous ground motions are generated by means of a new generation procedure implemented in the software GAS 2.0 using as input the simultaneous strong motion records from the April 6 th, 2009, L’Aquila(Italy) at the seismic stations AQA and AQV, located in the Aterno River valley. These records are used to calibrate the generation model and to produce sets of asynchronous earthquake sampling. The asynchronous earthquake sets are applied on a typical highway reinforced concrete bridge to study its dynamic response considering two different configurations: non-isolated with traditional supports and isolated bridge with lead rubber bearings. The bridge is placed in two positions along the wave propagation direction: a position near one recording station and a position between the two stations to consider local soil effects. The response parameters investigated are the maximum relative displacements of soil and deck. The results show that there is animportant variation of relative displacement along the direction of wave propagation due to asynchronous motion with effects that designer should consider for the structural details design of isolated and non-isolated bridges.

关键词： Asynchronous motion bridges Seismic response Earthquake spatial variability

Positioning in Dynamic Testing of Slender bridges

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Positioning 2011年第3期2卷 103-111页

作者： Alexander Tesar Jan Bencat 不详

The positioning combined with multi-functioning and interactive mechanics in dynamic testing of slender bridges are treated in present paper. The approach takes into account multiple functions in dynamic testing of slender bridges constructed of thin-walled structural members with their hierarchical configuration. Theoretical, numerical and experimental in situ assessments of the problem are presented. Some results of the application in situ are submitted.

关键词： bridges Deformation Positioning Dynamic Testing Interactive Mechanics Fourier Transformation Mul-ti-functioning Optimization Virtual Monitoring Wave Propagation

Some Observations on bridges Dynamic Behaviour

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Journal of Civil Engineering and Architecture 2020年第3期14卷 144-152页

作者： Jan B.Obrebski Faculty of Civil Engineering Warsaw University of TechnologyAl.Armii Ludowej 16Warsaw 00-637Poland

The paper presents rather some conclusions from large investigations over dynamic behaviour of bridges under travelling loads. There, as basic tool was applied the 3D-Time Space Method (3D-TSM) in edition proposed by present author. The method uses four-dimensional space, where besides of usual 3D space, the time is the fourth dimension. The bridge with simply supported steel girder is here modelled by means of theory for thin-walled bars (TWBs). In final calculations, solutions are obtained here on numerical way applying well known and simple Finite Differences Method (FDM). In consequence the task is brought to trivial determination of unknowns from set of linear algebraic equations. There, essential part of these equations is so called dynamical stiffness matrix (DSM). The last is additionally tested by Uniform Criterion (...) for evaluation of bridges Critical States (CrS).

关键词： bridges dynamic behaviour critical states critical velocity critical length uniform criterion 3D-time-space method

Strengthening of Concrete Box Girder bridges under Close-in Detonations

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Journal of Civil Engineering and Architecture 2012年第6期6卷 699-706页

作者： Ahmed Ibrahim Hani Salim Department of Civil Engineering and Construction Bradley University Peoria IL 61625 USA Department of Civil and Environmental Engineering University of Missouri Columbia MO 65211 USA

The response of a bridge superstructure under blast loading might depend largely on the extent of the local damage experienced due to close-in explosion threats. This paper investigates the local and structural response of box girder bridge decks strengthened using CFRP （carbon fiber reinforced polymers） under close-in detonations. Due to the lack of experimental research on this topic, the study is conducted using the explicit finite element computer program LS-DY-NA. The numerical study will be verified using the results of strengthened reinforced concrete slabs under field detonations. The blast load was assumed to be detonated above the bridge deck. The key parameters investigated are the charge size, and the strengthening location on the deck. This paper will present the results of this investigation and provides recommendations for predicting the local damage level based on the CFRP strengthening design under blast threat.

关键词： Pre-stressed blast box girder bridges carbon fiber.

Application of Non-destructive Testing to Evaluate the Performance of bridges Structures

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Journal of Civil Engineering and Architecture 2017年第1期11卷 1-7页

作者： Diego Jesus de Souza Elaine Souza dos Santos Eric Pianizolli Flor Gabriel Pereira Marinho Giovana Costa Reus Heloise Cristine Cezario Leticia Andrade Camara Department of Civil Engineering University of Ottawa Ottawa K2P0M1 Canada Department of Civil Construction Universidade Federal do Parana Sao Jose dos Pinhais 83040-334 Brazil Department of Civil Construction Universidade Federal do Parana Linhares 29902-190 Brazil Department of Civil Construction Universidade Federal do Parana Curitiba 80630-280 Brazil Department of Civil Construction Universidade Federal do Parana Campo Largo 83604-230 Brazil Department of Civil Construction Universidade Federal do Parana Curitiba 80060-120 Brazil

bridges are important elements in road system and can influence the entire economy of cities and region. Usually, these structures have high financial investments for their constructions, in this way, maintenance and conservation become so important. Inspection is a technical activity that covers several operations, including performance analysis; examination; final performance report, other operations may be necessary, such as maintenance work, recovery, strengthening and rehabilitation. Technical examination together with some test methods allows a critical and parametric judgment of the bridge performance by minimizing the subjectivity of visual evaluations, and permits a more detailed diagnosis. This paper discusses the methodology to perform tests to complement the assessment recommended by DNIT （Brazilian National Department of Transport Infrastructure）, which consists only on a visual judgment. This approach provides technical basis to classify the bridges as its need and urgency of maintenance.

关键词： Non-destructive testing bridges concrete durability.