• Title/Summary/Keyword: CHBDC

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Moment Equations for Long-Span Soil-Steel Box Culverts (장지간 지중강판 박스컬버트의 휨모멘트 식)

  • Choi, Dong-Ho;Lee, Seung-Jae;Kim, Nam-Gi
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.3
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    • pp.55-68
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    • 2006
  • This paper studies the moment equations in the 2000 Canadian highway bridge code(CHBDC) for soil-steel box structures, which are applicable to the span less than 8m. Finite element analyses carried out for soil-steel box structures having spans of 3-12m using the deep corrugated steel plates under three construction stages; backfill up to the crown, backfill up to the cover depth, and live loading. The coefficients of moment equations are newly proposed based on the results of numerous finite element analyses considering various design variables, such as span length, soil depth, backfill conditions. The validity of the proposed coefficients in the moment equations of the 2000 CHBDC is investigated by the comparison with the existing coefficients and numerical results of finite element analyses. The comparisons show that the moments of the 2000 CHBDC give good predictions for the span less than 8m, but underestimate for the span greater than 8m, whereas the proposed moments give good estimates of numerical results for the spans of 3-12m.

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Coefficients of Moment Equations for Long-Span Soil-Metal Box Structures (장지간 지중강판 박스구조물의 휨모멘트 계수식 제안)

  • Choi, Dong Ho;Lee, Seung Jae;Cho, Yong Woo;Park, Sang Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.133-142
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    • 2006
  • This paper evaluates the moment equations in the 2000 Canadian highway bridge code (CHBDC) for soil-metal box structures, which are applicable to the span less than 8 m. Finite element analyses carried out for soil-metal box structures having spans of 3-12 m using the deep corrugated metal plates under three construction stages; backfill up to the crown, backfill up to the cover depth, and live loading. The coefficients of moment equations are newly proposed based on the results of numerous finite element analyses considering various design variables, such as span length, soil depth, backfill conditions. The validity of the proposed coefficients in the moment equations of the 2000 CHBDC is investigated by the comparison with the existing coefficients and numerical results of finite element analyses. The comparisons show that the moments of the 2000 CHBDC give good predictions for the span less than 8m, but underestimate for the span greater than 8m, whereas the proposed moments give good estimates of numerical results for the spans of 3-12 m. In addition, this study suggests the use of high strength steel to satisfy the requirement of design bending strength for the span greater than 8 m.

Numerical Evaluation of Buckling Strength for High-Strength Corrugated Steel Structures (고강도 원형 지중강판 구조물의 좌굴성능에 대한 수치적 평가)

  • Choi, Dongho;Cho, Sunkyu;Park, Sangil;Moon, Eunkyung
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.6
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    • pp.75-88
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    • 2006
  • This paper evaluates the feasibility of use of high-strength steel for soil-metal corrugated steel structures. Two specifications, the AASHTO(2004) and the CHBDC(2000), were compared and the scientific background of equations for the buckling stability in those specifications were investigated to figure out the governing factors for buckling strength of structures. Numerous finite element analyses for round-pipe type of soil-metal corrugated steel structures were carried out with considering the elastic-plastic relationship of a material and the geometrical non-linearity, as well as the various design variables, such as span length, depths of soil cover, section properties, tensile strength and backfill conditions. Buckling strength equation of the CHBDC(2000) is still valid and conservative for both normal and high-strength steel soil-metal corrugated steel structures, and the buckling strength increases with the use of hight-strengths steel.

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Evaluation of Analysis Code of Corrugated Steel Plate Lining in Cut-and-Cover Tunnel (개착식 터널에서 파형강판 라이닝의 해석 기법 평가)

  • Kim, Jung-Ho;Kim, Nak-Young;Lee, Yong-Jun;Lee, Seung-Ho;Hwang, Young-Chul;Cho, Chul-Shin;Chung, Hyung-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1316-1323
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    • 2005
  • Most tunnel lining material which has been used in the domestic is a concrete. But many problems as the construction period, the cost, and the crack occurrence for the design, construction, and management were happened in the concrete lining. For this reason, many research institutes like the Korea Highway Corporation recognize the necessity of an alternate material development and grow on the interest for that. So in this study, the behaviour characteristics for the application of the Corrugated Steel Plate Lining in cut-and-cover tunnel are evaluated as several conditions for the backfill height, the cutting slope, and the relative density of backfill soil are changed. In addition, through using that conditions, CHBDC(2000, Canadian Highway Bridge Design Code) is evaluated if it could be applied to the design by comparing with the numerical analysis results. As the behaviour characteristics of the Corrugated Steel Plate Lining by CHBDC and the static numerical analysis are analyzed, both the methods show the same linear increases of the compressive stress according to the increase of the backfill height. The CHBDC of the dead load condition has very similar tendency by comparing with the result of the static numerical analysis.

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An analytical study on corrugated steel plate lining in cut-and-cover tunnel (개착식 터널에서 파형강판 라이닝 적용을 위한 해석적 연구)

  • Kim, Jung-Ho;Chung, Hyung-Sik
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.1
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    • pp.3-16
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    • 2004
  • A finite element method is used for the force analysis of semicircular arch shaped corrugated steel plate lining. The assessment of stability and behavior for several conditions are executed from the analysis of soil-structure interaction in accordance with CHBDC (Canadian Highway Bridge Design Code, 2000). One fortieth scaled model tests were conducted on the semicircular arch lining to verify the FEM analysis results under the earth-load conditions.

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Performance Evaluation of Encased-Concrete Bridge Plate(Deep Corrugated Steel Plate) Member (콘크리트 충전 브릿지 플레이트(대골형 파형강판) 부재의 성능평가)

  • Sim, Jong-Sung;Park, Cheol-Woo;Kim, Tae-Soo;Lee, Hyoung-Ho;Kang, Tae-Sung
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.297-303
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    • 2010
  • The current encased-concrete deep corrugated steel plate has an arch type plate structure, which is a compressive strength-dominant structure that has a small moment due to its arch shape. Therefore, it increases the strength against compression by adding reinforcements to make concrete-filling spaces for increasing the compressive strength and forming cross sections that contain reinforced concrete. In this study, the safety factor of the new-concept encased-concrete bridge plate member was evaluated by comparing the compressive strength obtained from the compressive tests, flexural tests and the design compressive strength determined by using the Canadian Highway Bridge Design Code (CHBDC, 2003), which is a design standard for the encased-concrete bridge plate structures. The results of the safety factor evaluation using the design compressive strength and the test results showed that the safety factor was well above the appropriate value 2.0, which could be adjudged very conservative. If the safety factor based on this study results is considered and applied to the design, economical construction will be possible due to the reduced cross section and construction cost.

Impact factors of an old bridge under moving vehicular loads

  • Liu, Yang;Yin, Xinfeng;Zhang, Jianren;Cai, C.S.
    • Structural Engineering and Mechanics
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    • v.46 no.3
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    • pp.353-370
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    • 2013
  • This paper presents a new method to study the impact factor of an old bridge based on the model updating technique. Using the genetic algorithm (GA) by minimizing an objective function of the residuals between the measured and predicted responses, the bridge and vehicle coupled vibration models were updated. Based on the displacement relationship and the interaction force relationship at the contact patches, the vehicle-bridge coupled system can be established by combining the equations of motion of both the bridge and vehicles. The simulated results show that the present method can simulate precisely the response of the tested bridge; compared with the other bridge codes, the impact factor specified by the bridge code of AASHTO (LRFD) is the most conservative one, and the value of Chinese highway bridge design code (CHBDC) is the lowest; for the large majority of old bridges whose road surface conditions have deteriorated, calculating the impact factor with the bridge codes cannot ensure the reliable results.

Reliability-based condition assessment of a deteriorated concrete bridge

  • Ghodoosi, Farzad;Bagchi, Ashutosh;Zayed, Tarek;Zaki, Adel R.
    • Structural Monitoring and Maintenance
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    • v.1 no.4
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    • pp.357-369
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    • 2014
  • In the existing bridge management systems, assessment of the structural behavior is based on the results of visual inspections in which corresponding condition states are assigned to individual elements. In this process, limited attention is given to the correlation between bridge elements from structural perspective. Also, the uncertainty of parameters which affect the structural capacity is ignored. A system reliability-based assessment model is potentially an appropriate replacement for the existing procedures. The aim of this research is to evaluate the system reliability of existing conventional Steel-Reinforced bridge decks over time. The developed method utilizes the reliability theory and evaluates the structural safety for such bridges based on their failure mechanisms. System reliability analysis has been applied to simply-supported concrete bridge superstructures designed according to the Canadian Highway Bridge Design Code (CHBDC-S6) and the deterioration pattern is achieved based on the reliability estimates. Finally, the bridge condition index of an old existing bridge in Montreal has been estimated using the developed deterioration pattern. The results obtained from the developed reliability-based deterioration model and from the evaluation done by bridge engineers have been found to be in accordance.

Evaluation of minimum depth of soil cover and reinforcement of soil cover above soil-steel bridge (지중강판 구조물의 최소토피고 평가 및 상부토피 보강 방안)

  • Jung, Hyun-Sik;Lee, Jong-Ku;Cho, Sung-Min;Kim, Myoung-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.425-432
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    • 2004
  • In this paper, the results of the numerical analysis for the minimum depth of soil cover have been compared with those of currently suggested codes. Based on this comparison, the minimum depth of soil cover for the structures with long spans was suggested. Results showed that the actual depth of the soil cover required against soil failure over a circular and low-profile arch structure does not vary significantly with the size of the span and for the circular structure, the minimum depth of the soil cover was about 1.5m, and for the low-profile arch structures, below about 1.6m. And the previously established code in which the minimum depth of soil cover is defined to linearly increase with the increase in the span (CHBDC, 2001) was very conservative. For the structure with the relieving slab, the maximum live load thrust was reduced by about 36 percent and the maximum moment about 81 percent. The numerical analysis gave more conservative estimation of the live-load thrusts than the other design methods.

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Numerical analysis of steel-soil composite (SSC) culvert under static loads

  • Beben, Damian;Wrzeciono, Michal
    • Steel and Composite Structures
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    • v.23 no.6
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    • pp.715-726
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    • 2017
  • The paper presents a numerical analysis of a steel-soil composite (SSC) culvert in the scope of static (dead and live) loads. The Abaqus program based on the finite element method (FEM) was used for calculations. Maximum displacements were obtained in the shell crown, and the largest stresses in the haunches. Calculation results were compared with the experimental ones and previous calculations obtained from the Autodesk Robot Structural Analysis (ARSA) program. The shapes of calculated displacements and stresses are similar to those obtained with the experiment, but the absolute values were generally higher than measured ones. The relative differences of calculated and measured values were in the range of 5-23% for displacements, and 15-42% for stresses. Developed calculation model of the SSC culvert in the Abaqus program allows obtaining reasonable values of internal forces in the culvert. Using both calculation programs, the relative differences for displacements were in the range of 15-39%, and 17-44% for stresses in favour of the Abaqus program. Three design methods (Sundquist-Pettersson, Duncan and CHBDC) were used to calculate the axial thrusts and bending moments. Obtained values were compared with test results. Generally, the design methods have conservative assumptions, especially in the live loads distribution, safety factors and consideration the interaction between soil and steel structure.