In-Situ Field Measurements and Numerical Model Identification of a Multi-Span Steel Railway Bridge

Abstract. It has been seen that bridges are vulnerable to earthquakes by the research studies after important earthquakes like the San Fernando earthquake (1971 USA), the Northridge earthquake (1994 USA), Great Hanshin earthquake (1995 Japan), and Chi-Chi earthquake (1999 Taiwan). These studies show that to do the seismic risk assessments for bridges, fragility curves are useful tools. There are the most used two ways to generate the fragility curves; empirically or analytically. If the damage reports from past earthquakes are available then empirical fragility curves may be developed but otherwise seismic response analysis of structures may be used to develop analytical fragility curves. In Turkey, earthquake damage data are very limited so to develop the fragility curves for the Alasehir bridge, the analytical method is used in this study. The bridge that is studied on is lying on the Manisa-Afyon railway line that is very important for both transportation and freightage. As the most of the country land covers the seismically active zones it is a necessity to find out the vulnerability of the Alasehir bridge. The Alasehir bridge is consists of six 30 m length truss system span with a total span length of 189.43 m supported by 2 abutments and 5 truss piers with height of 12.5 m, 19 m, 26 m, 33 m and 40 m. Sap2000 is used for computer model of the Alaşehir bridge and the model is refined by using field measurements. Then selected 60 different real earthquake data are used for the analysis by using the refined model. Both material nonlinearity and Δ-δ are considered during the analysis. With this study, seismic behavior of Alasehir steel railway bridge is determined. Truss piers reaction and displacements are used to determine the seismic performance of the Alasehir bridge. Different IMs are compared in terms of efficiency, practicality, and sufficiency. Component and system fragility curve are derived for most proper IMs.

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Evaluation of Performance Indicator of Railway Bridges Using Updated Finite Element Model

Strojnícky casopis – Journal of Mechanical Engineering ◽

10.2478/scjme-2019-0019 ◽

2019 ◽

Vol 69 (2) ◽

pp. 89-96

Author(s):

Sokol Milan ◽

Márföldi Monika ◽

Venglár Michal ◽

Lamperová Katarína

Keyword(s):

Health Monitoring ◽

Performance Indicator ◽

Element Model ◽

Fe Model ◽

Railway Bridge ◽

Railway Bridges ◽

Evaluation Of Performance ◽

Bridge Structures ◽

Steel Railway Bridge

AbstractStructural health monitoring (SHM) can provide information needed to make important decisions regarding the maintenance of bridge structures. However, the data collected from monitoring needs to be first translated into actionable, quantitative or qualitative based characteristics, that indicate the condition of a bridge. This paper presents a process of evaluation of such performance indicator in case of a steel railway bridge using the updated FE model and in-situ measurements of strains on selected stringers and floorbeams.

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Seismic assessment of a multi-span steel railway bridge in Turkey based on nonlinear time history

Natural Hazards and Earth System Science ◽

10.5194/nhess-18-231-2018 ◽

2018 ◽

Vol 18 (1) ◽

pp. 231-240 ◽

Cited By ~ 3

Author(s):

Mehmet F. Yılmaz ◽

Barlas Ö. Çağlayan

Keyword(s):

Fragility Curves ◽

Time History ◽

Field Measurements ◽

Response Analysis ◽

Railway Bridge ◽

Intensity Measures ◽

Railway Line ◽

Damage Data ◽

Steel Railway Bridge ◽

Nonlinear Time History

Abstract. Many research studies have shown that bridges are vulnerable to earthquakes, graphically confirmed by incidents such as the San Fernando (1971 USA), Northridge (1994 USA), Great Hanshin (1995 Japan), and Chi-Chi (1999 Taiwan) earthquakes, amongst many others. The studies show that fragility curves are useful tools for bridge seismic risk assessments, which can be generated empirically or analytically. Empirical fragility curves can be generated where damage reports from past earthquakes are available, but otherwise, analytical fragility curves can be generated from structural seismic response analysis. Earthquake damage data in Turkey are very limited, hence this study employed an analytical method to generate fragility curves for the Alasehir bridge. The Alasehir bridge is part of the Manisa–Uşak–Dumlupınar–Afyon railway line, which is very important for human and freight transportation, and since most of the country is seismically active, it is essential to assess the bridge's vulnerability. The bridge consists of six 30 m truss spans with a total span 189 m supported by 2 abutments and 5 truss piers, 12.5, 19, 26, 33, and 40 m. Sap2000 software was used to model the Alasehir bridge, which was refined using field measurements, and the effect of 60 selected real earthquake data analyzed using the refined model, considering material and geometry nonlinearity. Thus, the seismic behavior of Alasehir railway bridge was determined and truss pier reaction and displacements were used to determine its seismic performance. Different intensity measures were compared for efficiency, practicality, and sufficiency and their component and system fragility curves derived.

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Equivalent nosing force for a steel railway bridge based on in situ measurements

10.2749/ghent.2021.1273 ◽

2021 ◽

Author(s):

Lazar Georgiev ◽

Lyubomir Zdravkov ◽

Vatyu Tanev ◽

Milcho Lepoev

Keyword(s):

In Situ Measurements ◽

Railway Bridge ◽

Open Type ◽

Long Span ◽

Out Of Plane ◽

Design Loads ◽

The Republic ◽

Design Speed ◽

Steel Railway Bridge

<p>The weight and design speed of the railway vehicles increases in time. As a result, the values of design loads grow up. In old Bulgarian standard [1] the equivalent nosing force is prescribed as 60kN. In the present EN1991-2 [2] this value is 100kN. Meanwhile, a significant part of the very old bridges is not designed for nosing forces. In cases of long span between cross girders of the “open type” deck and lack of nosing braces, the load bearing capacity of longitudinal girders, concerning out of plane bending moments due to nosing forces, is insufficient. To investigate the value of equivalent nosing force are provided “in situ” measurements on the longitudinal girders of “open type” deck of a steel riveted railway bridge in exploitation in the Republic of Bulgaria. The strains and horizontal linear deformations are measured in the midspan of the longitudinal beams for real trains. The equivalent nosing force is calculated using developed procedures.</p>

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Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

Annals of Glaciology ◽

10.3189/1998aog26-1-174-178 ◽

1998 ◽

Vol 26 ◽

pp. 174-178 ◽

Cited By ~ 5

Author(s):

Peter Gauer

Keyword(s):

Numerical Simulation ◽

Numerical Model ◽

Three Dimensional ◽

Field Measurements ◽

Blowing Snow ◽

Related Field ◽

Drifting Snow ◽

Physically Based ◽

Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

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Underwater Holographic Sensor for Plankton Studies In Situ Including Accompanying Measurements

Sensors ◽

10.3390/s21144863 ◽

2021 ◽

Vol 21 (14) ◽

pp. 4863

Author(s):

Victor Dyomin ◽

Alexandra Davydova ◽

Igor Polovtsev ◽

Alexey Olshukov ◽

Nikolay Kirillov ◽

...

Keyword(s):

World Ocean ◽

Field Tests ◽

Field Measurements ◽

Measuring Systems ◽

Water Turbidity ◽

Background Data ◽

Average Size ◽

Size Dispersion

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

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Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽

10.3390/buildings11070276 ◽

2021 ◽

Vol 11 (7) ◽

pp. 276

Author(s):

Nisar Ali Khan ◽

Giorgio Monti ◽

Camillo Nuti ◽

Marco Vailati

Keyword(s):

Numerical Model ◽

Construction Materials ◽

Building Codes ◽

Construction Technique ◽

Infill Walls ◽

Mortar Strength ◽

Materials Used ◽

Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

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Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽

10.3390/w13081131 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1131

Author(s):

Soonkie Nam ◽

Marte Gutierrez ◽

Panayiotis Diplas ◽

John Petrie

Keyword(s):

Hydraulic Conductivity ◽

Field Measurements ◽

Natural Soil ◽

In Situ Tests ◽

Seepage Analysis ◽

Soil Deposits ◽

Seepage Modeling ◽

Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

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