• Computational Structural Engineering
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• v.10 no.2
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• pp.189-201
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• 1997

A number of standard type of steel-box pedestrian bridges are constructed in th metropolitan high way or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and load carrying capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model is formulated based on the von Mises' combined stress yield criterion. It has been demonstrated that the proposed model is effective for the reliability-based safety assessment and load carrying capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.60-68
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• 2012

This study describes an analytical and experimental investigation of the pedestrian steel-deck truss bridge in the City of Rochester, New York, U.S.A. This investigation was undertaken to provide assurance that this important bridge continues to be functional for this use. An ambient vibration experiment on full-scale structures is a way of assessing the reliability of the various assumptions employed in the mathematical models used in analysis. It is also the most reliable way of determining the structural parameters of major importance in structural dynamics, such as the mode shapes and the associated natural frequencies. Pedestrian-induced vibrations have been measured on the bridge to determine the displacement and the vertical and transverse dynamic characteristics of the steel deck truss. In the analytical modeling, three-dimensional finite element analysis was developed and validated against the ambient tests.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.5-8
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• 2004

About 175 vehicular bridges and 160 pedestrian bridges in service now, worldwide, are made of composites, completely of partially. In this paper, the status of this application is briefly explained.

• International Journal of Concrete Structures and Materials
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• v.7 no.1
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• pp.79-93
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• 2013

One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, and time dependent factors. The cracking of bridge decks not only creates unsightly aesthetic condition but also greatly reduces durability. It leads to a loss of functionality, loss of stiffness, and ultimately loss of structural safety. This investigation consists of field, laboratory, and analytical phases. The experimental and field testing investigate the early age transverse cracking of bridge decks and evaluate the use of sealant materials. The research identifies suitable materials, for crack sealing, with an ability to span cracks of various widths and to achieve performance criteria such as penetration depth, bond strength, and elongation. This paper also analytically examines the effect of a wide range of parameters on the development of cracking such as the number of spans, the span length, girder spacing, deck thickness, concrete compressive strength, dead load, hydration, temperature, shrinkage, and creep. The importance of each parameter is identified and then evaluated. Also, the AASHTO Standard Specification limits liveload deflections to L/800 for ordinary bridges and L/1000 for bridges in urban areas that are subject to pedestrian use. The deflection is found to be an important parameter to affect cracking. A set of recommendations to limit the transverse deck cracks in bridge decks is also presented.

• Computers and Concrete
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• v.24 no.4
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• pp.303-311
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• 2019

The depth of superstructure is the summation of the height of girders and the thickness of the deck floor. In this study, it is aim to determine the maximum span length of girders and minimum depth of the superstructure of prestressed concrete I-girder bridge. For this purpose the superstructure of the bridge with the width of 10m and the thickness of the deck floor of 0.175m, which the girders length was changed by two meter increments between 15m and 35m, was taken into account. Twelve different girders with heights of 60, 75, 90, 100, 110, 120, 130, 140, 150, 160, 170 and 180 cm, which are frequently used in Turkey, were chosen as girder type. The analyses of the superstructure of prestressed concrete I girder bridge was conducted with I-CAD software. In the analyses AASHTO LRFD (2012) conditions were taken into account a great extent. The dead loads of the structural and non-structural elements forming the bridge superstructure, prestressing force, standard truck load, equivalent lane load and pedestrian load were taken into consideration. HL93, design truck of AASHTO and also H30S24 design truck of Turkish Code were selected as vehicular live load. The allowable concrete stress limit, the number of prestressed strands, the number of debonded strands and the deflection parameters obtained from analyses were compared with the limit values found in AASHTO LRFD (2012) to determine the suitability of the girders. At the end of the study maximum span length of girders and equation using for calculation for minimum depth of the superstructure of prestressed concrete I-girder bridge were proposed.

• Journal of Korean Association for Spatial Structures
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• v.12 no.4
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• pp.99-108
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• 2012

In recently, sky-bridge are often applied to high-rised adjacent buildings for pedestrian bridge. the seisnic response control of adjacent buildings have been studied and magneto-rheological(MR) fluid dampers have been applied to seismic response control. In this study, vibration control effect of the MR damper connected adjacent buildings has been investigated. Adjacent building structures with different natural frequencies were used as example structures. Two typed of control methods, displacement based or velocity based, are applied to determinate control force of MR damper. In this numerical analysis, it has been shown that displacement-based control algorithm is more effective than velocity-based control algorithm for seismic response control of adjacent buildings. And, when displacement-based control method is applied to control of adjacent buildings, the control of building occurred large displacement is more efficient in reducing the seismic response.

• Journal of KIBIM
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• v.5 no.4
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• pp.47-52
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• 2015

This paper presents a case study using Building Information Modeling (BIM) for planning, simulating, and implementing complex site logistics in a headquarter office building construction project in Silver Spring, MD. As part of the project a prefabricated 92ft structural tube steel pedestrian connector bridge was installed between two adjacent buildings in the city of Silver Spring, MD. There were multiple significant challenges to deliver, offload, prepare, and install the connector bridge safely, on time, and with the minimum disturbances to the neighbors. BIM was of the foremost importance to visualize, simulate, analyze, improve, and communicate the site logistics plan from delivery to installation of the connector bridge. As a result of the effort, GC of the project was able to prepare a highly detailed plan, communicate it effectively to all stakeholders, and flawlessly execute the work as planned. This case study would provide a useful reference for contractors who are seeking a better planning method that enables generation of more accurate, implementable, optimized plans for complex site logistics.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.197-202
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• 2008

The Korea Land Corporation have planned Chongna site in Incheon as a great complex town including residence, financial center, resort, shopping mall, tour and sport. One of the large estate(17,800,000$m^2$) is under construction. Cheongna site is divided into six zoning parts, according to the meaning of 6 jewels(crystal, sapphire, ruby, emerald, jade, pearl, diamond). KLC required to me 6 pedestrian with various special forms and structural system. I will introduce a various pedestrians. There are not only 4 stayed and suspended bridges, but also a truss and arch bridges.

• KIEAE Journal
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• v.15 no.4
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• pp.53-60
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• 2015

Purpose: Subway in Seoul, Korea is an important urban mass transportation system as it carries more than 4 million people a day. To support this important mission, subway entrances were designed and installed to maximize accessibility to the stations. However, a uniform plan by the national government guided quantity and layout of the subway entrances. Therefore, the plan did not consider unique characteristics of each station area and reorganization of the subway entrance system is required to improve pedestrian environment. Method: This study grouped the subway entrances into specific patterns to propose reorganizing schemes. The authors conducted field surveys, examined case studies and proposed an entrance reorganizing plan for each type. Result: The study recommends subway entrances be installed inside adjacent building when large commercial or office complexes are nearby. The authors proposed installing a bridge connecting the stations and adjacent buildings for elevated entrances. This would be only possible when there are commercial or office facilities nearby with enough floor space. The study summarizes the pros and cons of each solution. To translate our proposals into realities, various incentives should be given to building or land owners. This study made suggestions as to which kinds of incentives exist and be effective in a range of situations.

• Smart Structures and Systems
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• v.24 no.5
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• pp.617-630
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• 2019

Currently most of the vision-based structural identification research focus either on structural input (vehicle location) estimation or on structural output (structural displacement and strain responses) estimation. The structural condition assessment at global level just with the vision-based structural output cannot give a normalized response irrespective of the type and/or load configurations of the vehicles. Combining the vision-based structural input and the structural output from non-contact sensors overcomes the disadvantage given above, while reducing cost, time, labor force including cable wiring work. In conventional traffic monitoring, sometimes traffic closure is essential for bridge structures, which may cause other severe problems such as traffic jams and accidents. In this study, a completely non-contact structural identification system is proposed, and the system mainly targets the identification of bridge unit influence line (UIL) under operational traffic. Both the structural input (vehicle location information) and output (displacement responses) are obtained by only using cameras and computer vision techniques. Multiple cameras are synchronized by audio signal pattern recognition. The proposed system is verified with a laboratory experiment on a scaled bridge model under a small moving truck load and a field application on a footbridge on campus under a moving golf cart load. The UILs are successfully identified in both bridge cases. The pedestrian loads are also estimated with the extracted UIL and the predicted weights of pedestrians are observed to be in acceptable ranges.