• Title/Summary/Keyword: Concrete slab

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Prediction of Failure Mode Under Static Loading in Long Span Bridge Deck Slabs by FEM (유한요소해석에 의한 장지간 바닥판의 정적파괴형태 예측)

  • Park, Woo Jin;Hwang, Hoon Hee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.52-59
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    • 2012
  • An analytical model is presented to predict the static behavior of the long-span prestressed concrete bridge deck(the long-span PSC deck). The finite element analysis is performed and the results are compared with that of the previous experimental test. The load-deflection relationship curves by FEM are in good agreement with the results reported in the previous study. The failure mode of all test specimens is predicted by the punching shear in this study. It is also observed in the previous experimental test. The main objective of this paper is presenting supportive method to predict static behavior of the long-span PSC deck slab. It is not simulating the punching shear behavior graphically.

Applicability of the Pile-Supported Embankment in Korea (성토지지말뚝공법의 국내 적용성 분석)

  • Lee, Il-Wha;Kim, Seung-Sun;Lee, Joo-Gong;Shim, Shung-Kyu;Lee, Su-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.32 no.3
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    • pp.5-13
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    • 2016
  • Stability analysis was conducted to analyze the application of pile-supported embankment to concrete slab track on the soft ground in Korea. Pile efficiency and tension of geosynthetics in accordance with the hight of embankment and the depth of soft soil were carried out by theoretical and numerical methods. Theoretical method predicted more conservatively than the numerical method for all the cases presented herein. The settlement stability is satisfied to allowable criteria of high speed railway in Korea. The pile-supported embankment has great potential for application to soft ground condition.

Influence of Inadequate Rebar Lap Position on Crack of Underground Box Slab (철근 겹침이음 위치 부적정이 지하박스 슬래브 균열 발생에 미치는 영향)

  • Choi, Jung-Youl;Jang, In-Soo;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.685-692
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    • 2020
  • In this study, the experimental and analytical study were performed on the location of longitudinal cracks in the middle of underground box structures. The location where the longitudinal cracking occurred was investigated that the overlapping joint of the rebar and the section of maximum tensile stress generated. Using the finite element analysis, the strength reduction ratio of the rebar was estimated by lack of overlap joint length. As the result of adequacy investigation for the length of the overlap joint presented in the design criteria, it was analytically proved that the lack of the overlap joint length could be cause the decreasing cross-sectional force and concrete cracking. As the result of this study, the adequacy of the overlapping criterion in the current design criteria was confirmed based on the finite element analysis and actual field case. In the case of overlapping joints installed in inappropriate position, it was considered that a long term crack control would be need to ensure the sufficient safety factor for the designed cross-sectional force.

Lateral Stiffness and Natural Period Evaluation of Flat Plate Tall Buildings for Wind Design (내풍설계를 위한 초고층 무량판 건축물의 횡강성 및 고유주기 산정)

  • Park, Je-Woo;Kim, Hong-Jin;Jo, Ji-Seong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.1
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    • pp.73-80
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    • 2010
  • Wind-induced vibration is one of the important structural design factors for serviceability of tall buildings. In order to evaluate the reliable wind-loads and wind induced-vibration, it is necessary to obtain the exact natural period of buildings. The discrepancy in the natural period estimation often results in the overestimation of wind loads. In this study, the effectiveness of lateral stiffness estimation method for tall buildings with flat plate system is evaluated. For this purposed, the results of finite element analysis of three recently constructed buildings are compared with those obtained from field measurement. For the analysis, factors affecting on the lateral resistance such as cracked stiffness of vertical members, elastic modulus of concrete, effective slab width, and cracked stiffness of link beam are considered. Form the results, it is found that the use of non-cracked stiffness and application of dynamic modulus of elasticity rather than initial secant modulus yields closer analysis result to the as-built period.

Standardization of composite connections for trapezoid web profiled steel sections

  • Saggaff, A.;Tahir, M.M.;Sulaiman, A.;Ngian, S.P.;Mirza, J.
    • Structural Engineering and Mechanics
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    • v.55 no.4
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    • pp.765-784
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    • 2015
  • Connections are usually designed either as pinned usually associated with simple construction or rigid normally is associated with continuous construction. However, the actual behaviour falls in between these two extreme cases. The use of partial strength or semi-rigid connections has been encouraged by Euro-code 3 and studies on semi-continuous construction have shown substantial savings in steel weight of the overall construction. Composite connections are proposed in this paper as partial or full strength connections. Standardized connection tables are developed based on checking on all possible failure modes as suggested by "component method" for beam-to-column composite connection on major axis. Four experimental tests were carried out to validate the proposed standardised connection table. The test results showed good agreement between experimental and theoretical values with the ratio in the range between 1.06 to 1.50. All tested specimens of the composite connections showed ductile type of failure with the formation of cracks occurred on concrete slab at maximum load. No failure occurred on the Trapezoidal Web Profiled Steel Section as beam and on the British Section as column.

Numerical analysis of channel connectors under fire and a comparison of performance with different types of shear connectors subjected to fire

  • Shahabi, S.E.M.;Ramli Sulong, N.H.;Shariati, M.;Mohammadhassani, M.;Shah, S.N.R.
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.651-669
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    • 2016
  • The behavior of shear connectors plays a significant role in maintaining the required strength of a composite beam in normal and hazardous conditions. Various types of shear connectors are available and being utilized in the construction industry according to their use. Channel connectors are a suitable replacement for conventional shear connectors. These connectors have been tested under different types of loading at ambient temperature; however, the behavior of these connectors at elevated temperatures has not been studied. This investigation proposes a numerical analysis approach to estimate the behavior of channel connectors under fire and compare it with the numerical analysis performed in headed stud and Perfobond shear connectors subjected to fire. This paper first reviews the mechanism of various types of shear connectors and then proposes a non-linear thermo-mechanical finite element (FE) model of channel shear connectors embedded in high-strength concrete (HSC) subjected to fire. Initially, an accurate nonlinear FE model of the specimens tested at ambient temperature was developed to investigate the strength of the channel-type connectors embedded in an HSC slab. The outcomes were verified with the experimental study performed on the testing of channel connectors at ambient temperature by Shariati et al. (2012). The FE model at ambient temperature was extended to identify the behavior of channel connectors subjected to fire. A comparative study is performed to evaluate the performance of channel connectors against headed stud and Perfobond shear connectors. The channel connectors were found to be a more economical and easy-to-apply alternative to conventional shear connectors.

A Study on the Section Change Using the Slip-Form Method (슬립폼 공법 적용 시 단면변화에 대한 고찰)

  • Suh, Jin-Sun;Han, Jun-Young;Im, Chil-Soon
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.123-128
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    • 2007
  • Already, core wall construction method for apartment wall structure and general building special areas applied the engineering method's appropriate examination. Also, trial and error depending on slip-form method is a good examination opportunity to consider. In the present paper's slip-form engineering method l)Casting concrete to slab in sliding 2)RC structure + SRC structure (part of segment) 3)Inside segment variation(straight line-diagonal-circle) are together while determining whether it is possible not to carry out actual construction work on the structure. Finally, small problems continuously appear on actual slip-form method application, design and engineering, starting with planning thoroughly the field examination and diagnosing the atmosphere, minimizing cost, secure work safety facilities characterized by good quality, slip-form research extension, development and decision-making.

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Analysis on Shear Force of Specimens Using Perfobond Rib Shear Connector (Perfobond Rib 전단연결재를 사용한 실험체의 전단강도 분석)

  • Choi, Jin Woong;Park, Byung Gun;Kim, Hyeong Jun;Jeong, Ho Seong;Park, Sun Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.1
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    • pp.138-147
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    • 2011
  • The objective of this study which it sees direct shear stress and comparative analysis of flexural shear stress leads and it is a shear stress analysis which it follows in load direction of the structure which uses Perfobond Rib shear connectors. To analyze direct shear stress, five Perfobond Rib shear connect experiments were fabricated with five variables and conducted Push-out Tests. After experiments, mechanism of Perfobond Rib shear connector was examined and direct shear formula was proposed based on primary factors which influence direct shear stress. Also, for the analysis of flexural shear steel-concrete composite slab specimens were fabricated and static flexural test. Based on the static flexural test it analyzed the flexural behavior and the flexural shear stress it calculated. Direct shear stress and EN 1994-1-1 to lead and be calculated, it compared the flexural shear stress and it analyzed in about the shear resistance stress which it follows in load direction.

Static Test and Suggestion of Shear Strength Equation on Shear Studs in Composite Bridge (합성형 교량에서 전단연결재에 대한 정적실험 및 강도식의 제안)

  • Yi, Seong-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.2
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    • pp.43-50
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    • 2018
  • In this study, to investigate the shear connection material for the composite of steel plate and bottom plate, design standards and research cases for shear connectors in various countries around the world were analyzed and shear tests were performed on the Push-out specimens with a shear connection, which transmits the horizontal shear force developed on the contact surface between the steel plate and the concrete slab due to various vertical loads acting on the bridge deck. Through Push-out tests of shear studs, of which FRP bar instead reinforcement is placed, the shear stud evaluation formula of the steel strap bottom plate was suggested. The suggested equation suggested in this study has the safety factor of approximately three times compared to allowable strength of highway bridge design criteria. In addition, compared to existing DIN standards and Viest assessment equation, the results showed similar values(approximately, 5% error).

Study on the Rolling Noise Model Using an Analysis of Wheel and Rail Vibration Characteristics (철도 차륜 및 레일 진동 특성 해석을 통한 전동 소음 모델 연구)

  • Jang, Seungho;Ryue, Jungsoo
    • Journal of the Korean Society for Railway
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    • v.16 no.3
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    • pp.175-182
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    • 2013
  • Rolling noise is an important source of noise from railways; it is caused by wheel and rail vibrations induced by acoustic roughness at the wheel/rail contact. To reduce rolling noise, it is necessary to have a reliable prediction model that can be used to investigate the effects of various parameters related to the rolling noise. This paper deals with modeling rolling noise from wheel and rail vibrations. In this study, the track is modeled as a discretely supported beam by regarding concrete slab tracks, and the wheel vibration is simulated by using the finite element method. The vertical and lateral wheel/rail contact forces are modeled using the linearized Hertzian contact theory, and then the vibration responses of the wheel and rail are calculated to predict the radiated noise. To validate the proposed model, a field measurement was carried out for a test vehicle. It was found that the predicted result agrees well with the measured one, showing similar behavior in the frequency range between 200 and 4000 Hz where the rolling noise is prominent.