• Structural Engineering and Mechanics
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• v.18 no.5
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• pp.609-626
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• 2004

The Land Transport Authority of Singapore has a continuing program of highway bridge upgrading, to refurbish and strengthen bridges to allow for increasing vehicle traffic and increasing axle loads. One subject of this program has been a short span bridge taking a busy highway across a coastal inlet near a major port facility. Experiment-based structural assessments of the bridge were conducted before and after upgrading works including strengthening. Each assessment exercise comprised two separate components; a strain and acceleration monitoring exercise lasting approximately one month, and a full-scale dynamic test carried out in a single day. This paper reports the application of extreme value statistics to estimate bridge live loads using strain measurements.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.143-153
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• 2006

In design of bridges, estimation of actions and loadings is very important for the safety and maintenance of bridges. In general, effect of traffic loading on the bridge can be modeled as live load (including impact load) and fatigue load. For estimation of traffic loading, it is important to get reliable and comprehensive truck statistical data such as the traffic and weight information. To get statistical data, Bridge Weigh-In-Motion (BWIM), which measures the truck weights without stopping the traffic, is need to be developed. In this study, BWIM system with various functions is developed first. Then this system is used to get comprehensive truck data. Traffic loadings including fatigue and live loading are formulated from the truck data acquired from the bridges. Objectives of this study are to develop the BWIM system, to apply the system in test bridge in Highway, and to formulate the live and fatigue loading for bridge design.

• Smart Structures and Systems
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• v.24 no.6
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• pp.723-732
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• 2019

Globally road transport networks are subjected to continuous levels of stress from increasing loading and environmental effects. As the most popular mean of transport in the UK the condition of this civil infrastructure is a key indicator of economic growth and productivity. Structural Health Monitoring (SHM) systems can provide a valuable insight to the true condition of our aging infrastructure. In particular, monitoring of the displacement of a bridge structure under live loading can provide an accurate descriptor of bridge condition. In the past B-WIM systems have been used to collect traffic data and hence provide an indicator of bridge condition, however the use of such systems can be restricted by bridge type, assess issues and cost limitations. This research provides a non-contact low cost AI based solution for vehicle classification and associated bridge displacement using computer vision methods. Convolutional neural networks (CNNs) have been adapted to develop the QUBYOLO vehicle classification method from recorded traffic images. This vehicle classification was then accurately related to the corresponding bridge response obtained under live loading using non-contact methods. The successful identification of multiple vehicle types during field testing has shown that QUBYOLO is suitable for the fine-grained vehicle classification required to identify applied load to a bridge structure. The process of displacement analysis and vehicle classification for the purposes of load identification which was used in this research adds to the body of knowledge on the monitoring of existing bridge structures, particularly long span bridges, and establishes the significant potential of computer vision and Deep Learning to provide dependable results on the real response of our infrastructure to existing and potential increased loading.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.429-432
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• 2000

Test methods by hydraulic oil or vehicular live load have been used for structural evaluation of prototype bridge. However it has been reported that the use of hydraulic jack has some disadvantages for the view of safety and economy, and the complete structural evaluation through each loading state can not be accomplished blocks is presented to overcome those demerits. To verify the application and safely of the use of concrete weight blocks during each loading state, it is applied to prototype deteriorated bridge. As a result, it could be evaluated the structural behavior completely using the concrete weight blocks

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.179-184
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• 2002

For the development of the practical design and analysis scheme of a bridge connecting to the typical VLFS, relevant design criteria and theory and techniques are studied and numerical analysis for the verification of the structural safety of the bridge are carried out. For the design of a typical steel bridge, characteristics of proper type bridge are reviewed and the requirements fur the bridge of this kind are studied as well as the environmental loads. By using the design spiral technique, several alternatives are investigated and an efficient type of a bridge is initially designed. Structural idealization is performed to make overall structural analysis first, and the structural behaviors of the proposed bridge in the given loading condition are evaluated. Through this study a bridge is finally proposed and it is found that this one works well for the connecting function of the bridge.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.3
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• pp.127-134
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• 2008

The response of a bridge can be influenced by span length, bridge's surface condition, vehicle's weight, and vehicle's velocity. It is difficult to predict accurate behavior of a bridge. In the current standard of specifications, such dynamic effect is defined by impact factor and prescribed to consider live load as to increase design load by means of multiplying this value by live load. However, it is not well understood because the Impact factor method differs from every country. Dynamic, static and pseudo-staitic field loading tests on PSC-I girder bridges were carried out to find out the dynamic property of the bridge. This paper is aimed to figure out actual dynamic property of the bridge by using field loading test. An empirical method based on impact factor is widely used and also argued. Displacement and strain response measured from the tests was compared with one from the empirical method. The former seems to be reasonable since it can consider actual response of a bridge through field tests.

• Structural Engineering and Mechanics
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• v.30 no.5
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• pp.559-576
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• 2008

Having established the initial geometry and cable force of a typical three span suspension bridge under permanent load, the additional maximum response of the cable and the stiffening girder due to live load are determined, by means of an analytic procedure, considering the girder first hinged at its ends and then continuous through the main towers. The problem of interaction between the cable and the stiffening girder is examined taking under due consideration the second order effects, whereby, through the analogy to a fictitious tensioned beam under transverse load, a closed -form solution is achieved by means of a simple quadratic equation. It is found that the behavior of the whole system is governed by five simple dimensionless parameters which enable a quick determination of all the relevant design magnitudes of the bridge. Moreover, by introducing these parameters, a set of diagrams is presented, which enable the estimation of the influence of the geometric and loading data on the response and permit its immediate evaluation for preliminary design purposes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.339-346
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• 2019

Various studies have been conducted to evaluate the probabilistic fatigue life of steel railway bridges, but many of them are based on a relatively simple model of crack propagation. The model assumes zero minimum stress and constant loading amplitude, which is not appropriate for the fatigue life evaluation of railway bridges. Thus, this study proposes a new probabilistic method employing an advanced crack propagation model that considers the live-dead load ratio for the fatigue life evaluation of steel railway bridges. In addition, by using the rainflow cycle counting algorithm, it can handle variable-amplitude loading, which is the most common loading pattern for railway bridges. To demonstrate the proposed method, it was applied to a numerical example of a steel railway bridge, and the fatigue lives of the major components and structural system were estimated. Furthermore, the effects of various ratios of live-dead loads on bridge fatigue life were examined through a parametric study. As a result, with the increasing live-dead stress ratio from 0 to 5/6, the fatigue lives can be reduced by approximately 30 years at both the component and system levels.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.04a
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• pp.207-212
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• 1993

Rail carrying structures in international routes as well as domestic ones shall be designed to carry HL(High Speed Railway live Load) loads, The loads shall be placed in the most unfavourable position for the part of the structure in question. In general, influence lines may be used to determine the maximum bending moments and maximum shear forces in the reinforced concrete rahmen bridge structures. In this study, based on the finite element analysis, equivalent distributed loads of HL loading for design of the rahmen bridges are deterimined.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.111-123
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• 2006

In the design of bridges, exact evaluation of traffic loading is very important for the safety and maintenance of bridges. In general, traffic loading is represented by live load (including impact load) and fatigue load. For exact evaluation of traffic loading, it is important to get reliable and comprehensive truck data including the traffic and weight information. It requires the development of Bridge Weigh-In-Motion (BWIM), which measures the truck weights without stopping the traffic. Objectives of the study is (1) to develop the BWIM system, (2) to verified the system in bridges in Highways.