• Wind and Structures
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• 제31권3호
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• pp.209-216
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• 2020

Aiming at the wind-resistant design of a sea-crossing arch bridge, the static aerodynamic coefficients of its girder (composed of stretches of π-shaped cross-section and box cross-section) were studied by using computational fluid dynamics (CFD) numerical simulation and wind tunnel test. Based on the comparison between numerical simulation, wind tunnel test and specification recommendation, a combined calculation method for the horizontal force coefficient of intermediate and small span bridges is proposed. The results show that the two-dimensional CFD numerical simulations of the individual cross sections are sufficient to meet the accuracy requirements of engineering practice.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1470-1477
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• 2010

In 2004, Korea has become the world's fifth-express train states, Honam high-speed railroad which goes down another line with existing Kyoungbu high-speed railroad is divided 19 construction sectors, its total length is 230.9 km and it will be constructed by 2017. This site is located in Jeollabukdo Jeong-eup district along 9.38 km. There are three representative bridges. ;One is the PSC box girder bridge, another is the Extradosed bridge, and the other is the three continuous spans half-through hybrid arch bridge. This paper shows a planning and design of these bridges.

• 한국강구조학회 논문집
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• 제21권4호
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• pp.361-373
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• 2009

유전자 알고리즘을 이용한 닐센아치교의 최적설계기법을 이 논문에서 제시하였다. 설계 매개변수로는 닐센아치교의 아치-라이즈비와 강중비에 대해서 최적화기법을 적용하여 각각의 거동을 분석하고, 적정성을 평가하여 최적의 매개변수 값을 결정하였다. 매개변수의 결정은 구조물의 안전성과 사용성 그리고 경제성에 중요한 설계인자로서 정형화가 요구된다. 이를 위해 최적화 기법으로 전역 최적해 탐색능력이 우수한 유전자 알고리즘을 사용하였으며, 설계 목적함수로는 구조물의 총 중량을 사용하였고, 제약조건으로는 변위, 응력, 시공성 제약조건을 두었다. 구조해석은 미소변위이론에 의한 탄성해석을 수행하여 유전자 알고리즘과 조합하여 병렬연산으로 수행시간을 단축시켰다. 이 연구에서 개발된 최적설계기법을 사용하여 최적의 아치-라이즈비와 강중비, 최적설계영역을 제시 하였으며 실무에 적용할 수 있도록 하였다.

• 한국조경학회지
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• 제35권4호
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• pp.48-56
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• 2007

This study was to understand the component that affects the formative beauty and to present the direction of bridge design for improving the image of urban landscape to survey the visual effect and landscape Preference by the change of bridge type. The results of this study are as follows. In the results of image analysis by bridge types, the images of one-arch bridges are unique and interesting, whereas more than two successive arched bridge were harmonize, stable, consecutive and regular. In the case of the arch rib, braced-rib arch bridge was assessed that complicated, diverse and interesting more than solid-rib arch bridge. The results of factor analysis on the psychological factor were classified into three categories: orderliness, aesthetic and symbolism. In the results of analysis on psychological factors by bridge types, the orderliness and symbolism were different in the position of path, and the number of arches, too. In case of arch rib, symbolism was different. In the preference analysis, they showed a sensitive reaction in the background of building. In the results of the relativity preference and psychological factor, according to aesthetic, symbolism and orderliness, there was an effect on the background of building. And, there showed the high effect in order of aesthetic, orderliness and symbolism in the background of mountain and building. This study should be objective raw data of the arch bridge design for improving the urban landscape. In the future, aesthetic variables like colors or textures should be considered for more exact evaluation.

• Structural Engineering and Mechanics
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• 제47권1호
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• pp.59-73
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• 2013

The Xiaolan channel super large bridge is unique in style and with greatest span in the world with a total length of 7686.57 m. The main bridge with spans arranged as 100m+220m+100m is a combined structure composed of prestressed concrete V-shape rigid frame and concrete-filled steel tubular flexible arch. First of all, the author compiles APDL command flow program by using the unit birth-death technique and establishes simulation calculation model in the whole construction process. The creep characteristics of concrete are also taken into account. The force ratio of the suspender, arch and beam is discussed. The authors conduct studies on the three-plate webs's rule of shear stress distribution, the box girder's longitudinal bending normal stress on every construction stage, meanwhile the distribution law of longitudinal bending normal stress and transverse bending normal stress of completed bridge's box girder. Results show that, as a new combined bridge, it is featured by: Girder and arch resist forces together; Moment effects of the structure are mainly presented as compressed arch and tensioned girder; The bridge type brings the girder and arch on resisting forces into full play; Great in vertical stiffness and slender in appearance.

• Structural Engineering and Mechanics
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• 제50권4호
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• pp.419-439
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• 2014

In this study, the structural performance of a seven span masonry arch bridge was evaluated. Investigations were performed on Aspendos (Belkis) Masonry Arch Bridge which was located on road of Aspendos Acropolis City in Antalya, Turkey. The old bridge was constructed in the early of fourth century AD, but it was exposed to the earthquakes in this region and the overloading by the river water. The old bridge was severely damaged and collapsed by probably an earthquake many years ago and a new bridge was then reconstructed on the remains of this old bridge by Seljuk in the 13th century. The bridge has also been affected from overflowing especially in the spring of each year, so some protective measures should be taken for this monumental bridge. Therefore, the structural performance under these loading has to be known. For this purpose, an initial finite element model was developed for the bridge and it was calibrated according to ambient vibration test results. After that, it was analyzed for different load cases such as dead, live, earthquake and overflow. Three load combinations were taken into account by deriving from these load cases. The displacements and the stresses for these combination cases were attained and compared with each other. The structural performance of Aspendos Masonry Arch Bridge was determined by considering the demand-capacity ratio for the tensile stress of the mortar used in Aspendos Masonry Arch Bridge. After these investigations, some concluding remarks and offers were presented at the end of this study.

• Structural Monitoring and Maintenance
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• 제2권1호
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• pp.65-75
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• 2015

Among the destruction instances of half-through arch bridges, the shorter hangers are more likely to be ruined. For a thorough investigation of the hanger system durability, we have studied vehicle impact effect on hangers with vehicle-bridge coupling method for a half-through concrete-filled-steel-tube arch bridge. A numerical method has been applied to simulate the variation of dynamic internal force (stress) in hangers under different vehicle speeds and road surface roughness. The characteristics and differences in impact effect among hangers with different length (position) are compared. The impact effect is further analyzed comprehensively based on the vehicle speed distribution model. Our results show that the dynamic internal force induced by moving vehicles inside the shorter hangers is significantly greater than that inside the longer ones. The largest difference of dynamic internal force among the hangers could be as high as 28%. Our results well explained a common phenomenon in several hanger damage accidents occurred in China. This work forms a basis for hanger system's fatigue analysis and service life evaluation. It also provides a reference to the design, management, maintenance, monitoring, and evaluation for this kind of bridge.

• Structural Engineering and Mechanics
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• 제61권5호
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• pp.645-655
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• 2017

To determine the seismic applicability of a long-span railway concrete upper-deck arch bridge with concrete-filled steel-tube (CFST) rigid skeleton ribs, some fundamental principles and seismic approaches for long-span bridges are investigated to update the design methods in the current Code for Seismic Design of Railway Engineering of China. Ductile and mixed isolation design are investigated respectively to compare the structural seismic performances. The flexural moment and plastic rotation demands and capacities are quantified to assess the seismic status of the ductile components. A kind of triple friction pendulum (TFP) system and lead-plug rubber bearing are applied simultaneously to regularize the structural seismic demands. The numerical analysis shows that the current ductile layout with continuous rigid frame approaching spans should be strengthened to satisfy the demands of rare earthquakes. However, the mixed isolation design embodies excellent seismic performances for the continuous girder approaching span of this railway arch bridge.

• Structural Engineering and Mechanics
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• 제39권4호
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• pp.521-539
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• 2011

Jilin highway concrete bridge is located in the center of Jilin City, which is positioned in the middle part in Jilin Province in the east north of China. This bridge crosses the Songhua River and connects the north and the south of Jilin City. The main purpose of damages inspection of the bridge components is to ensure the safety of a bridge and to identify any maintenance, repair, or strengthening which that need to be carried out. The damages that occur in reinforced concrete bridges include different types of cracks, scalling and spalling of concrete, corrosion of steel reinforcement, deformation, excessive deflection, and stain. The main objectives of this study are to inspect the appearance of Jilin highway concrete bridge and describe all the damages in the bridge structural members, and to evaluate the structural performance of the bridge structure under dead and live loads. The tests adopted in this study are: (a) the depth of concrete carbonation test, (b) compressive strength of concrete test, (c) corrosion of steel test, (d) static load test, and (e) dynamic load test. According to the damages inspection of the bridge structure appearance, most components of the bridge are in good conditions with the exception arch waves, spandrel arch, deck pavement of new arch bridge, and corbel of simply supported bridge which suffer from serious damages. Load tests results show that the deflection, strain, and cracks development satisfy the requirements of the standards.

• Coupled systems mechanics
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• 제10권1호
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• pp.1-19
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• 2021

Composite nature of the masonry structures in general causes complex and non-linear behaviour, especially in intense vibration conditions. The presence of different types and forms of structural elements and different materials is a major problem for the analysis of these type of structures. For this reason, the analysis of the behaviour of masonry structures requires a combination of experimental tests and non-linear mathematical modelling. The famous UNESCO Heritage Old Bridge in Mostar was selected as an example for the analysis of the global behaviour of reinforced stone arch masonry bridges. As part of the experimental research, a model of the Old Bridge was constructed in a scale of 1:9 and tested on a shaking table platform for different levels of seismic excitation. Non-linear mathematical modelling was performed using a combined finite-discrete element method (FDEM), including the effect of connection elements. The paper presents the horizontal displacement of the top of the arch and the failure mechanism of the Old Bridge model for the experimental and the numerical phase, as well as the comparison of the results. This research provided a clearer insight into the global behaviour of stone arch masonry structures reinforced with steel clamps and steel dowels, which is significant for the structures classified as world cultural heritage.