• Wind and Structures
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• 제17권2호
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• pp.203-225
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• 2013

An analysis framework for vehicle-bridge dynamic interaction system under turbulent wind is proposed based on the relevant theory of wind engineering and dynamics. Considering the fluctuating properties of wind field, the stochastic wind velocity time history is simulated by the Auto-Regressive method in terms of power spectral density function of wind field. The bridge is represented by three-dimensional finite element model and the vehicle by a multi-rigid-body system connected by springs and dashpots. The detailed calculation formulas of unsteady aerodynamic forces on bridge and vehicle are derived. In addition, the form selection of wind barriers, which are applied as the windbreak measures of newly-built railways in northwest China, is studied based on the suggested evaluation index, and the suitable values about height and porosity rate of wind barriers are studied. By taking a multi-span simply-supported box-girder bridge as a case study, the dynamic response of the bridge and the running safety indices of the train traveling on the bridge with and without wind barriers are calculated. The limit values of train speed with respect to different wind velocities are proposed according to the allowance values in the design code.

• Steel and Composite Structures
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• 제26권5호
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• pp.583-594
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• 2018

Although a lot of experimental and analytical investigations have been carried out for steel bridge piers made of SS400 and SM490, the formulas available for SS400 and SM490 are not suitable for evaluating ultimate load and deformation capacities of steel bridge piers made of high strength steel (HSS) SM570. The effect of various parameters is investigated in this paper, including plate width-to-thickness ratio, column slenderness ratio and axial compression force ratio, on the ultimate load and deformation capacities of steel bridge box piers made of SM570 steel subjected to cyclic loading. The elasto-plastic behavior of the steel bridge piers under cyclic loads is simulated through plastic large deformation finite element analysis, in which a modified two-surface model (M2SM) including cyclic hardening is employed to trace the material nonlinearity. An extensive parametric study is conducted to study the influences of structural parameters on the ultimate load and deformation capacities. Based on these analytical investigations, new formulas for predicting ultimate load and deformation capacities of steel bridge piers made of SM570 are proposed. This study extends the ultimate load and deformation capacities evaluation of steel bridge piers from SS400, SM490 steels to SM570 steel, and provides some useful suggestions.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.155-161
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• 2013

증강현실 기술은 가상의 정보와 현실의 배경을 혼합하여 사용자에게 제공하는 기술로, 현재 많은 분야에서 이 기술을 접목하여 다양한 연구를 진행하고 있다. 그 중 하나인 건설 산업은 복잡한 설계와 시설물을 기반으로 모든 업무가 행해지는 특징으로 인해 증강현실 기술의 활용 가능성이 높은 분야로 주목받고 있다. 또한 증강현실 기술은 현재 많은 사람들이 사용하고 있는 스마트폰에 구현되어 쉽고 빠르게 이용할 수 있게 되었다. 이에 본 논문에서는 콘크리트 교량의 유지 및 관리를 위해 증강현실 기반의 모바일 어플리케이션을 제안한다. 내/외적인 정보들을 제공하는 증강현실 기반 교량 정보 시스템을 제안한다. 본 논문에서 구현한 교량 정보 어플리케이션은 스마트폰과 증강현실 기술을 이용하여 교량의 다양한 정보를 제공할 수 있다.

• Structural Engineering and Mechanics
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• 제15권1호
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• pp.115-134
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• 2003

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast which reduces its section in steps, and it is strengthened by transverse cables and struts in the transverse vertical plane. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the threat from typhoons, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. This paper is devoted to the ambient vibration measurements of the bridge for evaluation of dynamic characteristics including the natural frequencies and mode shapes. It also describes the modelling of the bridge. A few finite element models are developed and calibrated to match with the field data and the results of subsequent structural health monitoring of the bridge.

• 한국도로학회논문집
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• 제15권1호
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• pp.103-110
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• 2013

PURPOSES: The objective of this study is to analyze and evaluate the behavior of orthotropic steel bridge deck pavement using three-dimensional finite element analysis and full-scale wheel load testing. METHODS: Since the layer thickness and material properties used in the bridge deck pavement are different from its condition, it is very difficult to measure and access the behavior of bridge deck pavement in the field. To solve this problem, the full-scale wheel load testing was conducted on the PSMA/Mastic bridge deck pavement and the deflection of bridge deck and horizontal tensile strain on top of pavement were measured under the loading condition. Three-dimensional finite element analysis was conducted to predict the behavior of bridge deck pavement and the predicted deflection and tensile strain values are compared with measured values from the wheel loading testing. RESULTS: Test results showed that the predicted deflections are 10% lower than measured ones and the error between predicted and measured horizontal tensile strain values is less than 2% in the critical location. CONCLUSIONS: The fact indicates that the proposed the analysis is found to be accurate for estimating the behavior of bridge deck pavements.

• Steel and Composite Structures
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• 제36권4호
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• pp.463-480
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• 2020

Although detailed shell analysis is suitable to predict the ductile crack initiation life of steel members, such detailed method adds time expense and complexity. In order to simply predict the ductile crack initiation life of stiffened steel bridge piers, a total of 33 cases are simulated to carry out the parametric analyses. In the analysis, the effects of the width-to-thickness ratio, slenderness ratio, plate thickness and so on are considered. Both shell analyses and beam analyses about these 33 cases are conducted. The plastic strain and damage index obtained from shell and beam analyses are compared. The modified factor β_s is determined based on the predicted results obtained from both shell and beam analyses in order to simulate the strain concentration at the base corner of the steel bridge piers. Finally, three experimental results are employed to verify the validity of the proposed method in this study.

• 한국안전학회지
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• 제27권5호
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• pp.88-94
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• 2012

In order to develop high performance concrete that overcome defects of asphalt and latex modified concrete for bridge deck overlay, this study aims to evaluate durability performance of concrete slab for bridge deck overlay. The present study is an exploratory research concerned with evaluation of two types of high performance concrete for bridge deck applications. This study is composed of a set of experiments, including static loading test and fatigue test and compared with data of defection, crack, concrete and steel strain. Also, experimental results were verified with analytical models by ABAQUS program. But overall behaviors of all specimens are comfortable, so those take sufficient load carrying capacity and high stiffness in cyclic load.

• 한국전산구조공학회논문집
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• 제27권5호
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• pp.403-412
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• 2014

이 연구에서는 물량저감 철근상세를 갖는 중공 철근콘크리트 교각 시스템의 전용 설계프로그램과 소성설계 적용 결과를 제시하였다. 개발된 물량저감 철근상세는 경제성과 합리성을 갖으며 공사기간의 단축을 가져올 수 있다. 물량저감 중공 철근콘크리트 교각의 적용을 통해 경제성 평가를 수행하였다. 평가 결과 개발상세가 기존상세에 비해 구조적 합리성, 시공성, 그리고 경제성 등이 우수함을 확인하였다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.319-326
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• 2000

The purpose of this study is to evaluate seismic performance of reinforced concrete pier columns in Seohae Ground Bridge. Since the bridge was designed before preparing the seismic design specification the bridge columns of hollow hexagonal section were designed and constructed with insufficient seismic reinforcement details such as longitudinal and transverse reinforcement lap-splices. In order to take the necessary measures to improve its seismic performance experimental study was performed by small-scale test for the bridge columns, From the quasi-static test for small-scale column specimens the lap-splices were not critical for overall behavior of the column if sufficient lap-splice-length was provided. The test results of failure mode effective stiffness ductility and equivalent viscous damping ratio are presented.

• Structural Engineering and Mechanics
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• 제11권3호
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• pp.259-272
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• 2001

The impact behavior of a multigirder concrete bridge under single and multiple moving vehicles is studied based on correlated road surface characteristics. The bridge structure is modeled as grillage beam system. A 3D nonlinear vehicle model with eleven degrees of freedom is utilized according to the HS20-44 truck design loading in the American Association of State Highway and Transportation Officials (AASHTO) specifications. A triangle correlation model is introduced to generate four classes of longitudinal road surface roughness as multi-correlated random processes along deck transverse direction. On the basis of a correlation length of approximately half the bridge width, the upper limits of impact factors obtained under confidence level of 95 percent and side-by-side three-truck loading provide probability-based evidence for the evaluation of AASHTO specifications. The analytical results indicate that a better transverse correlation among road surface roughness generally leads to slightly higher impact factors. Suggestions are made for the routine maintenance of this type of highway bridges.