• Smart Structures and Systems
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• v.29 no.5
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• pp.715-728
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• 2022

Recently, numbers of long span pedestrian suspension bridges have been constructed worldwide. While recent tragedies regarding pedestrian suspension bridges have shown how these bridges can wreak havoc on the society, there are no specific guidelines for construction standards nor safety inspections yet. Therefore, a structural health monitoring system that could help ensure the safety of pedestrian suspension bridges are needed. System identification is one of the popular applications for structural health monitoring method, which estimates the dynamic system. Most of the system identification methods for bridges are currently adapting output-only system identification method, which assumes the dynamic load to be a white noise due to the difficulty of measuring the dynamic load. In the case of pedestrian suspension bridges, the pedestrian load is within specific frequency range, resulting in large errors when using the output-only system identification method. Therefore, this study aims to develop a system identification method for pedestrian suspension bridges considering both input and output of the dynamic system. This study estimates the location and the magnitude of the pedestrian load, as well as the dynamic response of the pedestrian bridges by utilizing artificial intelligence and computer vision techniques. A simulation-based validation test was conducted to verify the performance of the proposed system. The proposed method is expected to improve the accuracy and the efficiency of the current inspection and monitoring systems for pedestrian suspension bridges.

• Smart Structures and Systems
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• v.22 no.6
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• pp.699-709
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• 2018

With increasing traffic volumes and rising vehicle traffic, especially in cities, the number of pedestrian bridges has also increased significantly. Like all other structures, pedestrian bridges also suffer damage. In order to increase the safety of pedestrians, it is necessary to identify existing damage and to repair them to ensure the safety of the bridge structures. Owing to the shortcomings of local methods in identifying damage and in order to enhance the reliability of detection and identification of structural faults, signal methods have seen significant development in recent years. In this research, a new methodology, based on cone-shaped kernel distribution with a new damage index, has been used for damage detection in pedestrian truss bridges. To evaluate the proposed method, the numerical models of the Warren Type steel truss and the Arregar steel footbridge were used. Based on the results, the proposed method and damage index identified the damage and determined its location with a high degree of precision. Given the ease of use, the proposed method can be used to identify faults in pedestrian bridges.

• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.55-64
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• 2017

An effective design approach for Multiple Tuned Mass Dampers (MTMDs) in pedestrian bridges was proposed by utilizing the transfer function to obtain each TMD's optimum stiffness and damping. A systematic simulation of pedestrian excitations was described. The motion equation of a typical MTMD system attached to a Multi-degree-of-freedom (MDOF) system was presented, and the transfer function from the input pedestrian excitations to the output acceleration responses was defined. By solving the minimum norm of the transfer function, the parameters of the MTMD which resulted in the minimum overall responses can be obtained. Two applications of lightly damped pedestrian bridges attached with MTMD showed that MTMDs designed through this method can significantly reduce the structural responses when subjected to pedestrian excitations, and the vibration control effects were better than the MTMD when it was considered as being composed of equal number and mass ratios of TMDs designed by classical Den Hartog method.

• Structural Engineering and Mechanics
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• v.83 no.6
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• pp.729-744
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• 2022

In this paper, an analytical formulation is proposed to predict the vertical vibration response due to the pedestrian walking on a footbridge considering the human-structure interaction, where the footbridge and pedestrian are represented by the Euler beam and linear oscillator model, respectively. The derived coupled equation of motion is a nonlinear fourth-order partial differential equation. An uncoupled solution strategy based on the combined weighted residual and perturbation method) is proposed to reduce the tedious computation, which allows the separate integration between the bridge and pedestrian subsystems. The theoretical study demonstrates that the pedestrian subsystem can be treated as a structural system with added mass, damping, and stiffness. The analysis procedure is then applied to a case study under the conditions of single pedestrian and multi pedestrians, and the results are validated and compared numerically. For convenient vibration design of a footbridge, the simplified peak acceleration formula and the idea of decoupling problem are thus proposed.

• Journal of The Korea Institute of Healthcare Architecture
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• v.9 no.1
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• pp.7-15
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• 2003

Contemporary hospital has more and more extension because the growth and change of hospital has to respond the various needs. For expanding, the sky bridge(sky walk) becomes one of the method to interconnect two or more buildings on the air. Sometimes the designers don't know exactly how the sky bridge works after construction. Beyond the role of interconnecting two buildings, the role of sky bridge is transformed the main axis of pedestrian in the whole hospital organization. This scope of analysis is about the sky bridge of Hanyang University hospital. The first method is the investigation of the utilization in this time. The second is the analysis of design drawings got form the designing of the past(1994-1998). From this analysis, the conclusions are followings.；The designer who wants to apply the sky bridge should more consider about, 1) how the sky bridge impacts the whole spatial system such as the pedestrian, patients, physicians, service's facilities etc. 2) what the inside of sky bridge has something such as natural light, ventilation, and the height, depth, width of aisle, the sign for seeking orientation. etc. In future the research relating sky bridge should be studied some hospital as well as one hospital for comparing the characteristics of the concepts and organizations

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.280-284
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• 2005

Existing construction materials such as concrete and steel have chronic problems; deterioration and corrosion. Owing to its special features of light weight ‘ high durability, anti-corrosion, composite material used in civil infrastructure can not only solve fundamental problems of deterioration and corrosion, but also reduce both construction and maintenance cost significantly. After the fabrication of deck panel with snap-fit connection by pultrusion through composite design according to stacking sequence of composite laminates and structural analysis, performance of decks will be verified and evaluated by structural tests.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.71-77
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• 2017

In this study, the boundary non-linear analysis of the sky bridge subjected to walking load and running load is performed. The sky bridge is installed in the mid-story between two buildings and the walking load and running load induced by pedestrians are measured by load cell. LRB is modeled as a non-linear hysteresis model to accurately represent the behavior of LRB. For the serviceability evaluation of sky bridge, the acceleration responses of sky bridge are analyzed based on ISO 2631-2 and the velocity response are analyzed based on standards Bachmann &Amann. In serviceability evaluation of this sky bridge, the pedestrian can not perceive the vibration except for resonance running loads consequently. Therefore, it is concluded that this sky bridge haven't problem in the serviceability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2474-2480
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• 2013

A stress ribbon pedestrian bridge is the structure in which the axial force of prestressed deck, which is developed by introducing prestressed force into the thin deck with the very low value of span to deck-depth ratio which is installed on bearing cables with the specified sag, resists most of external loadings. Since the design of stress ribbon pedestrian bridges should be conducted by assuming the cross-section of deck, the area of bearing cables and post-tensioning cables, and the prestressed force of post-tensioning cables, it requires much more iterative processes than the design of general bridges. In this research, to minimize such iteration processes, regression equations which can reasonably assume the area of bearing cables and post-tensioning cables, and the prestressed force of post-tensioning cables, are suggested for the bridge length of 80m with the sag-span ratios of 1/30, 1/40, and 1/50.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.539-544
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• 2007

Glass fiber reinforced composite decks have high-strength, light-weight and high durability. The composite decks having vertical snap-fit connections are designed for pedestrian bridges and their structural behaviour are studied. The existing connection method of the composite decks in horizontal direction is replaced by the developed snap-fit connection method in vertical direction. The section shape of the composite decks having the vertical snap-fit connection is designed. The safety of the vertical snap-fit connection is verified by finite element analysis.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.59-66
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• 2011

In this study, the vibration serviceability of pedestrian by travelling vehicles on the cable-stayed bridge with concrete tower was studied. Experiment variables were considered travelling speed of vehicles, pavement state of asphalt on the deck and weight of vehicles, preferentially. Especially, pavement grade states were considered by A and C grades by BMS (Bridge Management System) standard. The incremental ratio extent of vibration acceleration responses, asphalt pavement grade C over A, was construed to 1.23~1.43. Only, these results are valid within extent of the Scaled-Weight 228.0~1161.9 km/h kN. The vibration equations for acceleration responses prediction of bridge deck were proposed into three types, reliability 50%, 90%, 95% respectively. These equations can consider asphalt pavement grade, and the vehicle's weight and travelling velocity, which are the source of vibration, are combined into the term called, 'Scaled Weight'.