• Title/Summary/Keyword: Bridge pier

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Structrral Analysis of Bridge Pier with 40MPa High Strength Concrete (설계강도 40MPa 고강도 콘크리트를 적용한 교량 교각 구조물의 구조해석)

  • Hur, Jae-Hun;Yi, Sang-Keun;Gwak, Seok-Hwan;Huh, Suk-Bum;Park, Chang-Min
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.157-158
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    • 2009
  • In this study, We analyze structural behavior feature of column under reinforced-bar and concrete strength and load conditions and analyze optimal column diameter and construction cost through parameter study. In case we use the 40MPa high strength concrete instead of 27MPa concrete in pier, the results show positive effect in appearance of pier and cost because of small column diameter and low construction cost. Also, practical effect is proved by applying this results in pier of Shin Hou Bridge on Hum-Sung ${\sim}$ Chung-Ju highway construction work.

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Reliability Index Optimization for Pier Type Quay Walls Using Life Cycle Cost (생애주기비용을 이용한 잔교식 안벽의 신뢰도지수 최적화)

  • Kim, Dong-Hyawn;Yoon, Gil-Lim
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.6
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    • pp.422-428
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    • 2011
  • Optimal reliability indices were found by optimizing life cycle cost(LCC) of pier type quay walls. Failure probability of pier and shore bridge were calculated by response surface method. Then, they were used to obtain recovery cost after damage. Costs for initial construction and maintenance were also considered in finding optimal reliability indices. Target reliability indices which may be used in reliability based design were suggested by numerical examples under seismic load and ship load.

Study on lateral behavior of digging well foundation with consideration of soil-foundation interaction

  • Wang, Yi;Chen, Xingchong;Zhang, Xiyin;Ding, Mingbo;Lu, Jinhua;Ma, Huajun
    • Geomechanics and Engineering
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    • v.24 no.1
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    • pp.15-28
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    • 2021
  • Digging well foundation has been widely used in railway bridges due to its good economy and reliability. In other instances, bridges with digging well foundation still have damage risks during earthquakes. However, there is still a lack of knowledge of lateral behavior of digging well foundation considering the soil-foundation interaction. In this study, scaled models of bridge pier-digging well foundation system are constructed for quasi-static test to investigate their lateral behaviors. The failure mechanism and responses of the soil-foundation-pier interaction system are analyzed. The testing results indicate that the digging foundations tend to rotate as a rigid body under cyclic lateral load. Moreover, the depth-width ratio of digging well foundation has a significant influence on the failure mode of the interaction system, especially on the distribution of foundation displacement and the failure of pier. The energy dissipation capacity of the interaction system is discussed by using index of the equivalent viscous damping ratio. The damping varies with the depth-width ratio changing. The equivalent stiffness of soil-digging well foundation-pier interaction system decreases with the increase of loading displacement in a nonlinear manner. The absolute values of the interaction system stiffness are significantly influenced by the depth-width ratio of the foundation.

Experimental investigations of the seismic performance of bridge piers with rounded rectangular cross-sections

  • Shao, Guangqiang;Jiang, Lizhong;Chouw, Nawawi
    • Earthquakes and Structures
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    • v.7 no.4
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    • pp.463-484
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    • 2014
  • Solid piers with a rounded rectangular cross-section are widely used in railway bridges for high-speed trains in China. Compared to highway bridge piers, these railway bridge piers have a larger crosssection and less steel reinforcement. Existing material models cannot accurately predict the seismic behavior of this kind of railway bridge piers. This is because only a few parameters, such as axial load, longitudinal and transverse reinforcement, are taken into account. To enable a better understanding of the seismic behavior of this type of bridge pier, a simultaneous influence of the various parameters, i.e. ratio of height to thickness, axial load to concrete compressive strength ratio and longitudinal to transverse reinforcements, on the failure characteristics, hysteresis, skeleton curves, and displacement ductility were investigated. In total, nine model piers were tested under cyclic loading. The hysteretic response obtained from the experiments is compared with that obtained from numerical studies using existing material models. The experimental data shows that the hysteresis curves have significantly pinched characteristics that are associated with small longitudinal reinforcement ratios. The displacement ductility reduces with an increase in ratio of axial load to concrete compressive strength and longitudinal reinforcement ratio. The experimental results are largely in agreement with the numerical results obtained using Chang-Mander concrete model.

A Study on The Bed Scour at Stream Bridge during Flood - In the case of Jeongjang Bridge in Gurye - (홍수시 소하천 교량에서의 하상세굴 연구 - 구례 정장교를 중심으로 -)

  • Jung, Jae-Sung;Chung, Mahn;Kim, Min-Hwan
    • Journal of Environmental Science International
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    • v.11 no.10
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    • pp.1075-1080
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    • 2002
  • The hydrological frequency of the flood in July 2000 at Seosi stream basin in Gurye and the bed scour of the stream channel were estimated to investigate the bed scour related with Jeongjang bridge collapse. The storm over the basin in July 2000, 303mm/day was 103year frequency rainfall and the equivalent flood was 2580cms. As the results of 100year and 30year flood application, flood level 30.78~31.38m and mean velocity 3.79~4.03m/s were appeared. And the purification project of Seosi stream increased the velocity of the section near to Jeongjang bridge by the improvement of conveyance at the downstream. The local scour at pier was the major factor of bed scour at Jeongjang bridge site and the total scour at pier No.6 was increased from 2.32m to 2.45m by the purification project.

Monitoring bridge scour using dissolved oxygen probes

  • Azhari, Faezeh;Scheel, Peter J.;Loh, Kenneth J.
    • Structural Monitoring and Maintenance
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    • v.2 no.2
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    • pp.145-164
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    • 2015
  • Bridge scour is the predominant cause of overwater bridge failures in North America and around the world. Several sensing systems have been developed over the years to detect the extent of scour so that preventative actions can be performed in a timely manner. These sensing systems have drawbacks, such as signal inaccuracy and discontinuity, installation difficulty, and high cost. Therefore, attempts to develop more efficient monitoring schemes continue. In this study, the viability of using optical dissolved oxygen (DO) probes for monitoring scour depths was explored. DO levels are very low in streambed sediments, as compared to the standard level of oxygen in flowing water. Therefore, scour depths can be determined by installing sensors to monitor DO levels at various depths along the buried length of a bridge pier or abutment. The measured DO is negligible when a sensor is buried but would increase significantly once scour occurs and exposes the sensor to flowing water. A set of experiments was conducted in which four dissolved oxygen probes were embedded at different soil depths in the vicinity of a mock bridge pier inside a laboratory flume simulating scour conditions. The results confirmed that DO levels jumped drastically when sensors became exposed during scour hole evolution, thereby providing discrete measurements of the maximum scour depth. Moreover, the DO probes could detect any subsequent refilling of the scour hole through the deposition of sediments. The effect of soil permeability on the sensing response time was also investigated.

Desired earthquake rail irregularity considering random pier height and random span number

  • Jian Yu;Lizhong Jiang;Wangbao Zhou
    • Structural Engineering and Mechanics
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    • v.90 no.1
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    • pp.41-49
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    • 2024
  • In recent years, China's high-speed railway (HSR) line continues to expand into seismically active regions. Analyzing the features of earthquake rail irregularity is crucial in this situation. This study first established and experimentally validated a finite element (FE) model of bridge-track. The FE model was then combined with earthquake record database to generate the earthquake rail irregularity library. The sample library was used to construct a model of desired earthquake rail irregularity based on signal processing (SFT) and hypothesis principle. Finally, the effects of random pier height and random span number on desired irregularity were analyzed. Herein, an equivalent method of calculating earthquake rail irregularities for random structures was proposed. The results of this study show that the amplitude of desired irregularity is found to increase with increasing pier height. When calculating the desired irregularity of a structure with unequal pier heights, the structure can be regarded as that with equal pier heights (taking the largest pier height). For a structure with the span number large than 9, its desired irregularity can be considered equal to that of a 9-span structure. For the structures with both random pier heights and random span number, their desired irregularities are obtained by equivalent calculations for pier height and span number, respectively.

Study on Characteristics of Displacement and Stress of Piers under Adjacent load

  • Song, Bo;Zhang, Jingxing;Zhang, Zunke;Wang, Yanxuc;Kim, Taehwan
    • Journal of the Society of Disaster Information
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    • v.12 no.1
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    • pp.40-46
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    • 2016
  • Nowdays, adjacent loading bringing enormous harm to the existing bridge in engineering construction. In this paper, the influencing mechanism of adjacent loading to pier and Law of displacement of pier is researched through living examples, and the safe influence area has been defined. Research shows that: the main damages to piers is caused by the side loading; lateral displacement index of pier top surface is more conservative than the pier additional stress index; it is secure when the distance of adjacent load is 0.5 times of the height of accumulation or 6m, otherwise it would be very scary, and the monitoring measure is necessary.

Moment Control of Pier in Concrete Bridges Constructed by Free Cantilever Method (FCM 공법으로 시공되는 콘크리트 교량의 교각 모멘트 제어)

  • Yang, In-Hwan
    • Journal of the Korea Concrete Institute
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    • v.18 no.6 s.96
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    • pp.711-720
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    • 2006
  • The structural behavior of concrete girder in bridges constructed by free cantilever method is time-dependent due to creep and shrinkage of concrete. The constraint effects of longitudinal movement of concrete girders can introduce unfavourable moment into piers. This study is aimed at proposing a method to reduce the moment of piers in bridge constructed by free cantilever method. The method are systematically composed of time-dependent structural analysis of bridges and loading of control force during construction of bridge. Numerical analyses are carried out depending on the parameters such as amount of control force and flexibility of pier. Time-dependent structural behavior shows that moment of pier increases according as pier height decreases. Also, moment of pier decreases when control method are applied. Numerical result of the study represents that time-dependent moment of piers can be controlled effectively by employing the proposed method.

Experimental and numerical investigation of the seismic performance of railway piers with increasing longitudinal steel in plastic hinge area

  • Lu, Jinhua;Chen, Xingchong;Ding, Mingbo;Zhang, Xiyin;Liu, Zhengnan;Yuan, Hao
    • Earthquakes and Structures
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    • v.17 no.6
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    • pp.545-556
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    • 2019
  • Bridge piers with bending failure mode are seriously damaged only in the area of plastic hinge length in earthquakes. For this situation, a modified method for the layout of longitudinal reinforcement is presented, i.e., the number of longitudinal reinforcement is increased in the area of plastic hinge length at the bottom of piers. The quasi-static test of three scaled model piers is carried out to investigate the local longitudinal reinforcement at the bottom of the pier on the seismic performance of the pier. One of the piers is modified by increased longitudinal reinforcement at the bottom of the pier and the other two are comparative piers. The results show that the pier failure with increased longitudinal bars at the bottom is mainly concentrated at the bottom of the pier, and the vulnerable position does not transfer. The hysteretic loop curve of the pier is fuller. The bearing capacity and energy dissipation capacity is obviously improved. The bond-slip displacement between steel bar and concrete decreases slightly. The finite element simulations have been carried out by using ANSYS, and the results indicate that the seismic performance of piers with only increasing the number of steel bars (less than65%) in the plastic hinge zone can be basically equivalent to that of piers that the number of steel bars in all sections is the same as that in plastic hinge zone.