Structural Engineering and Mechanics

  • 제62권6호
  • /
  • Pages.725-737
  • /
  • 2017
  • /
  • 1225-4568(pISSN)
  • /
  • 1598-6217(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Short- and long-term analyses of shear lag in RC box girders considering axial equilibrium

  • Xiang, Yiqiang (Department of Civil Engineering, Zhejiang University) ;
  • He, Xiaoyang (Department of Civil Engineering, Zhejiang University)
  • 투고 : 2016.09.29
  • 심사 : 2017.05.23
  • 발행 : 2017.06.25
⟨ 이전 논문 다음 논문 ⟩

초록

An analytical method considering axial equilibrium is proposed for the short- and long-term analyses of shear lag effect in reinforced concrete (RC) box girders. The axial equilibrium of box girders is taken into account by using an additional generalized displacement, referred to as the longitudinal displacement of the web. Three independent shear lag functions are introduced to describe different shear lag intensities of the top, bottom, and cantilever plates. The time-dependent material properties of the concrete are simulated by the age-adjusted effective modulus method (AEMM), while the reinforcement is assumed to behave in a linear-elastic fashion. The differential equations are derived based on the longitudinal displacement of the web, the vertical displacement of the cross section, and the shear lag functions of the flanges. The time-dependent expressions of the generalized displacements are then deduced for box girders subjected to uniformly distributed loads. The accuracy of the proposed method is validated against the finite element results regarding the short- and long-term responses of a simply-supported RC box girder. Furthermore, creep analyses considering and neglecting shrinkage are performed to quantify the time effects on the long-term behavior of a continuous RC box girder. The results show that the proposed method can well evaluate both the short- and long-term behavior of box girders, and that concrete shrinkage has a considerable impact on the concrete stresses and internal forces, while concrete creep can remarkably affect the long-term deflections.

키워드

과제정보

연구 과제 주관 기관 : National Natural Science Foundation of China

참고문헌

  1. Bazant, Z.P. (1972), "Prediction of concrete creep effects using age-adjusted effective modulus method", ACI J., 69(4), 212-217.
  2. Bazant, Z.P., Yu, Q. and Li, G.H. (2012a), "Excessive long-time deflections of prestressed box girders. I: Record-span bridge in Palau and other paradigms", J. Struct. Eng., ASCE, 138(6), 676-686. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000487
  3. Bazant, Z.P., Yu, Q. and Li, G.H. (2012b), "Excessive long-time deflections of prestressed box girders. II: Numerical analysis and lessons learned", J. Struct. Eng., ASCE, 138(6), 687-696. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000375
  4. Cao, G.H. (2000), "Analysis and experimental study on shear lag effect of RC box girder", M.Sc. Dissertation, Hunan University, Changsha, China. (in Chinese)
  5. CEB-FIP model code 1990 (1993), Model Code for Concrete Structures, Euro-International Committee for Concrete-International Federation for Prestressing; Lausanne, Switzerland.
  6. Dezi, L. and Mentrasti, L. (1985), "Nonuniform bending-stress distribution (shear lag)", J. Struct. Eng., ASCE, 111(12), 2675-2690. https://doi.org/10.1061/(ASCE)0733-9445(1985)111:12(2675)
  7. Dezi, L., Gara, F. and Leoni, G. (2003), "Shear-lag effect in twin-girder composite decks", Steel Compos. Struct., 3(2), 111-122. https://doi.org/10.12989/scs.2003.3.2.111
  8. Dezi, L., Gara, F., Leoni, G. and Tarantino, A.M. (2001), "Time-dependent analysis of shear-lag effect in composite beams", J. Eng. Mech., ASCE, 127(1), 71-79. https://doi.org/10.1061/(ASCE)0733-9399(2001)127:1(71)
  9. Elbadry, M., Ghali, A. and Gayed, R.B. (2014), "Deflection control of prestressed box girder bridges", J. Bridge Eng., ASCE, 19(5), 04013027. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000564
  10. Gara, F., Leoni, G. and Dezi, L. (2009), "A beam element including shear lag effect for the time-dependent analysis of steel-concrete composite decks", Eng. Struct., 31(8), 1888-1902. https://doi.org/10.1016/j.engstruct.2009.03.017
  11. Gara, F., Ranzi, G. and Leoni, G. (2010), "Short- and long-term analytical solutions for composite beams with partial interaction and shear-lag effects", Int. J. Steel Struct., 10(4), 359-372. https://doi.org/10.1007/BF03215844
  12. Ghali, A., Favre, R. and Elbadry, M. (2012), Concrete Structures: Stresses and Deformations, Analysis and Design for Serviceability, (4th Edition), Spon Press, London, UK.
  13. Gilbert, R.I. and Ranzi, G. (2011), Time-dependent Behavior of Concrete Structures, Spon Press, London, UK.
  14. Granata, M.F., Margiotta, P. and Arici, M. (2013), "Simplified procedure for evaluating the effects of creep and shrinkage on prestressed concrete girder bridges and the application of European and North American prediction models", J. Bridge Eng., ASCE, 18(12), 1281-1297. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000483
  15. Guo, T. and Chen, Z.H. (2016), "Deflection control of long-span PSC box-girder bridge based on field monitoring and probabilistic FEA", J. Perform. Constr. Facil., ASCE, 30(6), 04016053. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000909
  16. Jirasek, M. and Bazant, Z.P. (2002), Inelastic Analysis of Structures, Wiley, Chichester, UK.
  17. Kristek, V. and Bazant, Z.P. (1987), "Shear lag effect and uncertainty in concrete box girder creep", J. Struct. Eng., ASCE, 113(3), 557-574. https://doi.org/10.1061/(ASCE)0733-9445(1987)113:3(557)
  18. Kristek, V. and Kadlec, L. (2014), "The cross-section warping effect with the associated creep-induced deformations", Adv. Eng. Softw., 72, 213-217. https://doi.org/10.1016/j.advengsoft.2013.06.015
  19. Lacidogna, G. and Tarantino, M. (1996), "Approximate expressions for the ageing coefficient and the relaxation function in the viscoelastic analysis of concrete structures", Mater. Struct., 29(3), 131-140. https://doi.org/10.1007/BF02486158
  20. Lin, Z.B. and Zhao, J. (2011a), "Least-work solutions of flange normal stresses in thin-walled flexural members with high-order polynomial", Eng. Struct., 33(10), 2754-2761. https://doi.org/10.1016/j.engstruct.2011.05.022
  21. Lin, Z.B. and Zhao, J. (2011b), "Revisit of AASHTO effective flange-width provisions for box girders", J. Bridge Eng., ASCE, 16(6), 881-889. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000194
  22. Lou, T.J., Lopes, S.M.R. and Lopes, A.V. (2014), "A finite element model to simulate long-term behavior of prestressed concrete girders", Finite Elem. Anal. Des., 81, 48-56. https://doi.org/10.1016/j.finel.2013.11.007
  23. Lou, T.J., Lopes, S.M.R. and Lopes, A.V. (2015a), "FE analysis of short- and long-term behavior of simply supported slender prestressed concrete columns under eccentric end axial loads causing uniaxial bending", Eng. Struct., 85, 52-62. https://doi.org/10.1016/j.engstruct.2014.12.023
  24. Lou, T.J., Lopes, S.M.R. and Lopes, A.V. (2015b), "Interaction between time-dependent and second-order effects of externally posttensioned members", J. Bridge Eng., ASCE, 20(11), 06015003. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000761
  25. Lou, T.J., Lopes, S.M.R. and Lopes, A.V. (2016), "Time-dependent behavior of concrete beams prestressed with bonded AFRP tendons", Compos. Part B: Eng., 97, 1-8. https://doi.org/10.1016/j.compositesb.2016.04.070
  26. Luo, Q.Z., Wu, Y.M., Li, Q.S., Tang, J. and Liu, G.D. (2004), "A finite segment model for shear lag analysis", Eng. Struct., 26(14), 2113-2124. https://doi.org/10.1016/j.engstruct.2004.07.010
  27. Malm, R. and Sundquist, H. (2010), "Time-dependent analyses of segmentally constructed balanced cantilever bridges", Eng. Struct., 32(4), 1038-1045. https://doi.org/10.1016/j.engstruct.2009.12.030
  28. Norachan, P., Kim, K.D. and Onate, E. (2014), "Analysis of segmentally constructed prestressed concrete bridges using hexahedral elements with realistic tendon profiles", J. Struct. Eng., ASCE, 140(6), 04014028. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000923
  29. Pan, Z.F., Fu, C.C. and Jiang, Y. (2011), "Uncertainty analysis of creep and shrinkage effects in long-span continuous rigid frame of Sutong Bridge", J. Bridge Eng., ASCE, 16(2), 248-258. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000147
  30. Reissner, E. (1946), "Analysis of shear lag in box beams by the principle of the minimum potential energy", Q. Appl. Math., 4(3), 268-278. https://doi.org/10.1090/qam/17176
  31. Robertson, I.N. (2005), "Prediction of vertical deflections for a long-span prestressed concrete bridge structure", Eng. Struct., 27(12), 1820-1827. https://doi.org/10.1016/j.engstruct.2005.05.013
  32. Sousa, C., Sousa, H., Neves, A.S. and Figueiras, J. (2012), "Numerical evaluation of the long-term behavior of precast continuous bridge decks", J. Bridge Eng., ASCE, 17(1), 89-96. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000233
  33. Sousa, H., Bento, J. and Figueiras, J. (2014), "Assessment and management of concrete bridges supported by monitoring databased finite-element modeling", J. Bridge Eng., ASCE, 19(6), 05014002. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000604
  34. Takacs, P.F. (2002), "Deformations in concrete cantilever bridges: Observations and theoretical modelling", Ph.D. Dissertation, The Norwegian University of Science and Technology, Trondheim, Norway.
  35. Wen, Q.J. (2011), "Long-term effect analysis of prestressed concrete box-girder bridge widening", Constr. Build. Mater., 25(4), 1580-1586. https://doi.org/10.1016/j.conbuildmat.2010.09.041
  36. Wu, Y.P., Liu, S.Z., Zhu, Y.L. and Lai, Y.M. (2003), "Matrix analysis of shear lag and shear deformation in thin-walled box beams", J. Eng. Mech., ASCE, 129(8), 944-950. https://doi.org/10.1061/(ASCE)0733-9399(2003)129:8(944)
  37. Xiang, Y.Q. and He, X.Y. (2015), "Time-dependent behavior of PC box girder bridges considering non-uniform shrinkage and creep", J. Harbin Inst. Tech., 47(12), 117-122. (in Chinese)
  38. Xiang, Y.Q., Tang, G.B. and Liu, C.X. (2011), "Cracking mechanism and simplified design method for bottom flange in prestressed concrete box girder bridge", J. Bridge Eng., ASCE, 16(2), 267-274. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000151
  39. Yang, I.H. (2007a), "Uncertainty and sensitivity analysis of time-dependent effects in concrete structures", Eng. Struct., 29(7), 1366-1374. https://doi.org/10.1016/j.engstruct.2006.07.015
  40. Yang, I.H. (2007b), "Prediction of time-dependent effects in concrete structures using early measurement data", Eng. Struct., 29(10), 2701-2710. https://doi.org/10.1016/j.engstruct.2007.01.015
  41. Zhang, Y.H. (2012), "Improved finite-segment method for analyzing shear lag effect in thin-walled box girders", J. Struct. Eng., ASCE, 138(10), 1279-1284. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000552
  42. Zhang, Y.H. and Lin, L.X. (2014a), "Shear lag analysis of thin-walled box girders adopting additional deflection as generalized displacement", J. Eng. Mech., ASCE, 140(4), 04014005. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000705
  43. Zhang, Y.H. and Lin, L.X. (2014b), "Shear lag analysis of thin-walled box girders based on a new generalized displacement", Eng. Struct., 61, 73-83. https://doi.org/10.1016/j.engstruct.2013.12.031
  44. Zhou, S.J. (2010), "Finite element considering shear-lag effect in box girder", J. Eng. Mech., ASCE, 136(9), 1115-1122. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000156