• Structural Engineering and Mechanics
• /
• v.5 no.4
• /
• pp.399-414
• /
• 1997

This paper presents an investigation into the seismic response characteristics of a proposed ligh-weight pedestrian cable-stayed bridge made entirely from Glass Fiber Reinforced Plastics(GFRP). The study employs three dimensional finite element models to study and compare the dynamic characteristics and the seismic response of the GFRP bridge to a conventional Steel-Concrete (SC) cable-stayed bridge alternative. The two bridges were subjected to three synthetic earthquakes that differ in the frequency content characteristics. The performance of the GFRP bridge was compared to that of the SC bridge by normalizing the live load and the seismic internal forces with respect to the dead load internal forces. The normalized seismically induced internal forces were compared to the normalized live load internal forces for each design alternative. The study shows that the design alternatives have different dynamic characteristics. The light GFRP alternative has more flexible deck motion in the lateral direction than the heavier SC alternative. While the SC alternative has more vertical deck modes than the GFRP alternative, it has less lateral deck modes than the GFRP alternative in the studied frequency range. The GFRP towers are more flexible in the lateral direction than the SC towers. The GFRP bridge tower attracted less normalized base shear force than the SC bridge towers. However, earthquakes, with peak acceleration of only 0.1 g, and with a variety of frequency content could induce high enough seismic internal forces at the tower bases of the GFRP cable-stayed bridge to govern the structural design of such bridge. Careful seismic analysis, design, and detailing of the tower connections are required to achieve satisfactory seismic performance of GFRP long span bridges.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.210-218
• /
• 2019

Recently, cable-stayed bridges have been attempting to apply bold and experimental shapes for aesthetic and originality. In the case of bridges that have no similar cases, deep understanding and verification of analytical modeling is needed. S-shaped curved pedestrian cable-stayed bridge is always twisted because the cable is arranged on one side of the inverted triangular truss girder. In order to suppress the torsion, the Link-shoes are arranged at the left and right top members with reference to the Bearing placed at the mid-bottom member. The first research is related to the modeling method of Link-Shoe and Diaphram. In order to accurately reflect the transverse structural system and the torsional stiffness, it was necessary to model the Link-Shoe and the Diaphram directly rather than indirectly using the stiffness of the Bearing. The second study is related to the lateral arrangement of Bearing and Link-Shoes. Method 1 is to place in order of Link-shoe, Bearing, and Link-shoe from outside the curve radius. Method 2 is place to in order of Bearing, Bearing, and Link-shoe. In method 2, compared to method 1, the stress in the outer top member was larger and the stress in the inner one was decreased. It is analyzed that the stress adjustment is possible according to the lateral arrangement of Bearing and Link-Shoe.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.577-584
• /
• 2019

Recently, CSB(Cable-Stayed Bridge) have been attempted to be atypical forms for landscape elements in Korea. CSB with new geometry need to analyze their characteristics clearly to ensure structural safety. This study's bridge is the S-shaped curved pedestrian CSB that has a girder with S-shape plane curve and reverse triangular truss cross section, inclined independent pylon, modified Fan type main cable and vertical backstay cable. Curved CSB can have excessive lateral displacement and moment when the tension is adjusted, focusing only on longitudinal behavior, such as a straight CSB. In order to analyze the effect of the cable on the lateral behavior of bridges, the cable is divided into two groups according to the lateral displacement direction of the pylon due to tension. The influence of the combination ratio of GR1 and GR2 on the girder, bearing, pylon, and vertical anchor cable was analyzed. When the tension applied to the bridge is 1.0GR1 plus 1.0GR2, In the combination of 1.2GR1 plus 0.8GR2, the stress on the left and right upper member of the truss girder and the deviation of the both were minimized. In addition, the horizontal force of the bearing, the lateral displacement and moment of the pylon, and the tension of the vertical backstay cable also decreased. This study is expected to be used as basic data for determination of tension of CSB with similar geometry.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2004.05a
• /
• pp.197-205
• /
• 2004

A vocabulary for a understanding bridge has a different scope. There are the urban setting, landscape, lightness, from minimum to maximum, continuity, material, erection, motion and dynamic. Aesthetics criteria of footbridge design are movement and grace, space and experiment, symbolism, iconic, sculpture, innovation, spectacle, lighting, gemetry and wonder. New structural concepts of pedestrian bridges are presented on examples of recently built structures. The main characteristics of described structures are appropriateness, humanity, structural efficiency and aesthetics.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.11
• /
• pp.6898-6905
• /
• 2014

A stress ribbon bridge is a PSC structure that behaves as a reverse arch structure due to post-tensioned thin deck of the catenary type. In foreign countries, the stress ribbon bridge is recognized as the minimum destruction of nature and beautiful bridge, and has many construction examples as pedestrian and car bridges. On the other hand, there have been few studies in Korea. In this study, the FE Analysis model was established for different construction stages considering the nonlinear and time-dependent behaviors. The FE model was verified by a comparison with the numerical results and the behavior was analyzed for the different construction stages.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.34 no.4 s.117
• /
• pp.61-68
• /
• 2006

A park will soon be developed in an area of Gwangjang-dong, Gwangjin-gu. The place has been a patch of green space for years, isolated by driveways and apartment complexes and abandoned. This article describes plans to infuse the abandoned green space with history, ecology, culture, and sports. The facilities that are to be constructed in and around the green space are positioned to take into account the path of the sun and the location of the curvilinear green space axis. The cultural space is planned as a centerpiece of the park, linked with the sports facilities. The overall framework is arranged in harmony with nearby elementary schools, parks, public facilities, athletic facilities, parking lots, and apartment complexes. The themed circulation route was constructed according to the environmental conditions and the spatial plan. In addition, the historical space is planned to work in close conjunction with the cultural space, and the streets and pedestrian pathways have characters of their own. The established contour lines will be carefully preserved, and an ecological pond will. The facilities, such as the outdoor performance stage, the outdoor art gallery, the Monument of Wind represented by a sail, and the pedestrian bridge in memory of Acha-sansung, are positioned for spatial balance and to provide a nexus. The bamboo forest, designed to foster the experience of sound effects, the architectural thematic plants, and the ecological pond are positioned to connect to each other around the greenspace axis. The main facilities are the outdoor theater, the bamboo forest, the Acha-sansung bridge, the Monument of Wind, the ecological pond, the four-season flower garden, parking lots, playgrounds, circulatory athletic pathways, and the tennis court.

• Steel and Composite Structures
• /
• v.18 no.1
• /
• pp.149-163
• /
• 2015

Orthotropic steel highway bridges exist almost everywhere in world, especially in Europe. The design of these bridges started very early in 20th century and ended with a conventional orthotropic steel bridge structure, which is today specified in DIN FB 103. These bridges were mostly built in 1960's and exhibit damages in steel structural parts. The primary reason of these damages is the high pressure that is induced by wheel- loads and therefore damages develop especially in heavy traffic lanes. Constructive rules are supplied by standards to avoid damages in orthotropic steel structural parts. These rules are first given in detail in the standard DIN 18809 (Steel highway- and pedestrian bridges- design, construction, fabrication) and then in DIN- FB 103 (Steel bridges). Bridges built in the past are today subject to heavier wheel loads and the frequency of loading is also increased. Because the vehicles produced today in 21st century are heavier than before and more people have vehicle in comparison with 20th century. Therefore dimensioning or strengthening of orthotropic steel bridges by using stiffer dimensions and shorter spans is an essence. In the scope of this study the complex geometry of conventional steel orthotropic bridge is generated by FE-Program and the effects of cross beam web thickness and cross beam span on steel bridge are assessed by means of a parameter study. Consequently, dimensional and constructional recommendations in association with cross beam thickness and span will be given by this study.

• Steel and Composite Structures
• /
• v.23 no.2
• /
• pp.205-215
• /
• 2017

The use of advanced fibre composite materials in bridge engineering offers alternative solutions to structural problems compared to traditional construction materials. Advanced composite or fibre reinforced polymer (FRP) materials have high strength to weight ratios, which can be especially beneficial where dead load or material handling considerations govern a design. However, the reduced weight and stiffness of FRP footbridges results in generally poorer dynamic performance, and vibration serviceability is likely to govern their design to avoid the footbridge being "too lively". This study investigates the dynamic behaviour of the 51.3 m span Wilcott FRP suspension footbridge. The assessment is performed through a combination of field testing and finite element analysis, and the measured performance of the bridge is being used to calibrate the model through an updating procedure. The resulting updated model allowed detailed interpretation of the results. It showed that non-structural members such as the parapets can influence the dynamic behaviour of slender, lightweight footbridges, and consequently their contribution must be included during the dynamic assessment of a structure. The test data showed that the FRP footbridge is prone to pedestrian induced vibrations, although the measured response levels were lower than limits specified in relevant standards.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.11a
• /
• pp.263-269
• /
• 2003

This paper describes the vibration control using a tuned mass damper(TMD) for the existing footbridge. The footbridge connecting driveway to the Stadium is the simple steel box-girder bridge with the main span length of 44.6m. This footbridge has light weight(=25.3kN/m) and pedestrians walking on the footbridge were found to induce resonance at the fundamental mode of the structure, resulting in unacceptable accelerations in it. Taking into account economical and constructional benefits, TMD was designed to damp the vibrations of the modes next to the natural frequency caused by a pedestrian, with a limitation criteria of vertical amplitude. A set of two 500kgf vertical TMDs was manufactured by KR and installed into the railings next to the central section of this footbridge. The installation of TMDs reduced the peak acceleration in the meeting box to less than 90%. It is hoped that the study will present bridge engineers with a measure of retrofitting footbridges to make them more friendly to users.

• Journal of KIBIM
• /
• v.6 no.3
• /
• pp.42-48
• /
• 2016

Structural members are designed to maintain the load-carrying capacity as well as structural strength, and the structural serviceability such as the deflection, cracks, and vibration to give the occupants uncomfortable environment should be checked. Recently, the importance of the vibration has been issued since the Techno Mart accident due to vibration resonance. This study provides a passive vibration control system using the repulsion force of magnets to reduce dynamic vibrations. The systems is devised by importing the constraint condition by a hinge to operate magnets installed at two adjacent locations. The effectiveness of the proposed system is investigated by the vibration control test of a steel beam with and without the control system. It is illustrated in the test that the system is activated by the control forces executed by the magnets and can be utilized in reducing the dynamic responses. The system can be applied to pedestrian bridge and traffic bridge. The applicability is expected in the future by optimizing the factors to affect the dynamic responses like the intensity, mass, locations of magnets.