• 건축역사연구
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• 제16권3호
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• pp.7-20
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• 2007

A bridge is a space used as a passage. This space should be functional, solid, and beautiful. Since the beginning of human life, bridge architecture has given importance to function as a connection from one place to another. Stepping stones in the stream were the connections between divided spaces in the agricultural life, the bridge on the entrances of a town was the place for separation, expectation, and communication for people gathering around the community. Southern Chinese provinces such as Zhejiang, Hunan, Yunnan, and Guizhon is famous for it's spectacular scenary, and tribes like the 'Miao' and 'Dong' live in a cooperate community. The 'Dong' tribe is one of the 'Yue' genealogy where the people have settled down in this place in the days of 'Qin Shi Huang(Qin dynasty)'. As the population of the 'Dong' tribe growed, they used a bridge to connect town to town. The scale became larger with additional design, giving splendid achievement to bridge architecture. The 'Fungyu bridge' in Tongdao and 'Chungyang bridge' in Sanjiang are some fine examples. The Fungyu bridge could be defined as a bridge which blocks wind and rain, this has the same function as the lounge bridge in Taishun located in southern Zhejiang province. In Taishun, 5 minority races such as the 'Dong' and 'Miao' people have been living together as a clan society for centuries on mountains as high as 1000m following their own tradition. The 'Xiliu river' flowing thorough has a variety of bridges remaining in it's original form, and it is recently known as a museum of ancient bridges. The formation of the bridges in Tongdao and Taishun shows that it is different with the arch and straight bridges remaining in Korea. In this study, it is readjusting the base data, showing plan characteristics and describing the construction of the wooden structure above the bridge post.

• Earthquakes and Structures
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• 제10권5호
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• pp.1089-1109
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• 2016

Modified two-surface model (M2SM) is one of the steel elasto-plastic hysteretic constitutive models that consider both analysis accuracy and efficiency. However, when M2SM is used for complex strain history, sometimes the results are irrational due to the limitation of stress-strain path judgment. In this paper, the defect of M2SM was re-modified by improving the judgment of stress-strain paths. The accuracy and applicability of the improved method were verified on both material and structural level. Based on this improvement, the nonlinear time-history analysis was carried out for a deck-through steel arch bridge with a 200 m-long span under the ground motions of Chi-Chi earthquake and Niigata earthquake. In the analysis, we compared the results obtained by hysteretic constitutive models of improved two-surface model (I2SM) presented in this paper, M2SM and the bilinear kinematic hardening model (BKHM). Results show that, although the analysis precision of displacement response of different steel hysteretic models differs little from each other, the stress-strain responses of the structure are affected by steel hysteretic models apparently. The difference between the stress-strain responses obtained by I2SM and M2SM cannot be neglected. In significantly damaged areas, BKHM gives smaller stress result and obviously different strain response compared with I2SM and M2SM, and tends to overestimate the effect of hysteretic energy dissipation. Moreover, at some position with severe damage, BKHM may underestimate the size of seismic damaged areas. Different steel hysteretic models also have influences on structural damage evaluation results based on deformation behavior and low cycle fatigue, and may lead to completely different judgment of failure, especially in severely damaged areas.

• 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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• 제22권2호
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• pp.173-183
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• 2010

본 논문은 I형 강재와 프리캐스트 콘크리트 바닥판으로 구성된 비합성 합성아치 생태교량에 대한 해석 및 실험 연구이다. 범용유한 요소해석 프로그램 ABAQUS(2007)를 사용하여 단위거더, 단위합성거더, 3거더 아치, 3거더 합성아치 등 4종류의 해석모델이 검토되었으며, 해석 결과를 토대로 모델별 거동특성을 분석하고, 3거더 합성아치 모형실험체에 설치될 응력 및 변형률 게이지 위치를 결정하였다. 본 연구의 정적파괴 하중실험에 사용된 실험체는 3개의 I형강 거더와 14개의 PC패널로 구성되어 있다. 모형실험체 정적파괴실험결과로부터 강거더 하부플랜지가 항복응력에 도달하는 시기의 재하하중은 유한요소해석을 통해 얻어진 정적하중과 17%정도의 차이를 나타내고 있으며, 실험체 파괴하중은 1,961kN으로 AASHTO LRFD 교량설계기준 (2007)의 단면 소성모멘트를 이용한 작용가능하중은 1,380kN으로 본 실험체는 충분한 내하력을 나타내고 있다. 해석결과와 실험결과를 토대로 새로운 형식의 비합성 합성아치 교량의 안전성과 강도가 충분히 발휘됨을 확인할 수 있었다.

• Smart Structures and Systems
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• 제15권3호
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• pp.645-663
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• 2015

Recently, an indirect displacement estimation method using data fusion of acceleration and strain (i.e., acceleration-strain-based method) has been developed. Though the method showed good performance on beam-like structures, it has inherent limitation in applying to more general types of bridges that may have complex shapes, because it uses assumed analytical (sinusoidal) mode shapes to map the measured strain into displacement. This paper proposes an improved displacement estimation method that can be applied to more general types of bridges by building the mapping using the finite element model of the structure rather than using the assumed sinusoidal mode shapes. The performance of the proposed method is evaluated by numerical simulations on a deck arch bridge model and a three-span truss bridge model whose mode shapes are difficult to express as analytical functions. The displacements are estimated by acceleration-based method, strain-based method, acceleration-strain-based method, and the improved method. Then the results are compared with the exact displacement. An experimental validation is also carried out on a prestressed concrete girder bridge. The proposed method is found to provide the best estimate for dynamic displacements in the comparison, showing good agreement with the measurements as well.

• 한국구조물진단유지관리공학회 논문집
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• 제8권4호
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• pp.175-183
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• 2004

아치교량의 미관과 경제성을 고려할 때 가장 중요한 요소가 라이즈 비 이며, 이러한 라이즈 비를 결정하는데 있어 현재는 자중에 의한 영향만을 고려하고 있다. 본 연구에서는 아치교량의 라이즈 비 검토시 현재 고려하고 있는 자중에 의한 영향뿐만 아니라 최근 중요시 되고 있는 지진하중에 대한 동적안정성 문제를 라이즈 비 결정인자로 추가하여 자중에 의한 라이즈 비 결정이 가지고 있는 문제점에 대하여 검토하였다. 그 결과 라이즈 비 선정시 지진하중에 대한 동적안정성은 필히 고려되어야 할 것으로 판단되었다.

• 한국방재학회 논문집
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• 제11권1호
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• pp.15-22
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• 2011

본 논문에서는 아치 형상을 갖는 강재 거더에 콘크리트가 충진되고 외부에 긴장력을 도입하여 구조적 효율성을 높인 CFTA 거더(Concrete-Filled and Tied Steel Tubular Arch Girder)의 아치효과와 구조적 성능을 검증하기 위해 정적하중재하실험을 수행하였고, 실험결과의 타당성을 검증하기 위해 유한요소해석을 수행하였다. CFTA 거더는 강재, 콘크리트, PS강재 등을 이용하여 각 재료의 역학적 장점을 최대한 발휘하도록 형상화하였다. 본 연구에서는 프레임해석프로그램으로 지간장 12m인 축소모형을 설계하였으며, 해석결과에 근거하여 정적재하실험이 수행되었다. 정적재하실험 결과, CFTA 거더의 구조적 성능과 안전성이 검증되었으며, 아치 효과에 의해 타 구조형식과는 다른 처짐 형상이 나타났다. 또한 ABAQUS 프로그램을 이용한 유한요소해석을 통해 차량 충돌 안정성과 정적재하실험결과의 타당성을 입증하였다.

• Smart Structures and Systems
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• 제17권6호
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• pp.1087-1105
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• 2016

Traffic load and volume is one of the most important physical quantities for bridge safety evaluation and maintenance strategies formulation. This paper aims to conduct the statistical analysis of traffic volume information and the multimodal modeling of gross vehicle weight (GVW) based on the monitoring data obtained from the weigh-in-motion (WIM) system instrumented on the arch Jiubao Bridge located in Hangzhou, China. A genetic algorithm (GA)-based mixture parameter estimation approach is developed for derivation of the unknown mixture parameters in mixed distribution models. The statistical analysis of one-year WIM data is firstly performed according to the vehicle type, single axle weight, and GVW. The probability density function (PDF) and cumulative distribution function (CDF) of the GVW data of selected vehicle types are then formulated by use of three kinds of finite mixed distributions (normal, lognormal and Weibull). The mixture parameters are determined by use of the proposed GA-based method. The results indicate that the stochastic properties of the GVW data acquired from the field-instrumented WIM sensors are effectively characterized by the method of finite mixture distributions in conjunction with the proposed GA-based mixture parameter identification algorithm. Moreover, it is revealed that the Weibull mixture distribution is relatively superior in modeling of the WIM data on the basis of the calculated Akaike's information criterion (AIC) values.

• 한국조경학회지
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• 제30권5호
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• pp.31-38
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• 2002

This study attempts to grasp the correlation between the image of bridges and bridge landscapes with their surroundings during day and nighttime viewing, and to understand the psychological influence of nighttime lighting through quantitative analysis. In addition, it presents a design to construct bridges in order to increase viewers enjoyment of bridge landscapes lit at night. To attain this objective and contrive generalization of the results, this paper selects 8 of 9 bridges with lightings in Seoul and excludes bridges constructed by 2004. The criteria for selection of the viewpoints is that each must be within easy reach of bridges, and must allow viewers to recognize surrounding landscape details both in daylight and at night. As well, the pictures of bridges are taken in the terraced land by the riverside. The study selects 16 pictures, judged to be of similar quality and angle, to establish the conditions of luminosity, color, definition and angle. The results are as follows. First, viewers preferences of night landscapes are higher than day landscapes due to the effect of lighting. By day, viewers preferred bridges with various structures such as cable-stayed bridges and arch bridges more than simple bridges like girder bridges. Viewers also indicated preferences for lightings which feature a unique color and which are harmonized with their surroundings. Second, components representing the images of bridge landscape are classified into three types, 'beauty', 'system' and 'agreeableness'. Third, the factors affecting preference are the shape of bridge by day and lighting at night. Esthetic appeal is the most important factor in visual preference so each bridges own esthetic appeal and surroundings must be considered. Thus, a complete plan must be created which considers safety, beauty and the local surroundings. In addition, when the lighting of a bridge is selected, the design of the bridge landscape must consider various lighting schemes to harmonize the upper and lower parts of the structure. At this point, the study reveals the basic elements of bridge planning in order to increase appreciation of the bridge landscape.

• International Journal of Concrete Structures and Materials
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• 제1권1호
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• pp.29-36
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• 2007

The purpose of this paper is the assessment of the capacity of the reinforced concrete (RC) elements of an arch bridge when they are subjected to contact and near-contact explosive charges of various amounts, and the estimation of the critical charges for these components. The bridge considered is the Tenza Viaduct, a decommissioned structure south of Naples, Italy. Its primary elements, deck, piers and arches were analyzed. The evaluation was accomplished via numerical analyses that made possible to obtain the elements dynamic response when they are exposed to blast loading conditions. To evaluate the member's capacities, failure criteria for deck, piers and arches were proposed based on concrete damage parameters. Additionally, curves relating the explosive charge to the residual capacity and to damage level of the elements were also developed. The results of this work were taken into account to investigate the progressive collapse of the global structure.