Wind and Structures

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Two case studies on structural analysis of transmission towers under downburst

  • Yang, FengLi (Engineering Mechanics Department, China Electric Power Research Institute) ;
  • Zhang, HongJie (Engineering Mechanics Department, China Electric Power Research Institute)
  • Received : 2015.07.24
  • Accepted : 2016.04.15
  • Published : 2016.06.25
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Abstract

Downbursts are of great harm to transmission lines and many towers can even be destroyed. The downburst wind field model by Chen and Letchford was applied, and the wind loads of two typical transmission towers in inland areas and littoral areas were calculated separately. Spatial finite element models of the transmission towers were established by elastic beam and link elements. The wind loads as well as the dead loads of conductors and insulators were simplified and applied on the suspension points by concentrated form. Structural analysis on two typical transmission towers under normal wind and downburst was completed. The bearing characteristics and the failure modes of the transmission towers under downburst were determined. The failure state of tower members can be judged by the calculated stress ratios. It shows that stress states of the tower members were mainly controlled by 45 degree wind load. For the inland areas with low deign wind velocity, though the structural height is not in the highest wind velocity zone of downburst, the wind load under downburst is much higher than that under normal wind. The main members above the transverse separator of the legs will be firstly destroyed. For the littoral areas with high deign wind velocity, the wind load under downburst is lower than under normal wind. Transmission towers are not controlled by the wind loads from downbursts in design process.

Keywords

Acknowledgement

Supported by : National Natural Science Foundation of China

References

  1. American Society of Civil Engineering (2010), ASCE manuals and reports on engineering practice No.74, Reston, USA.
  2. Australia/New Zealand Standard (2010), Overhead line design-Detailed procedures AS/NZS 7000, Sydeny, Australia.
  3. British Standards Institution (2005), Lattice tower and masts-Part1. Code of practice for loading BS-8100, London, British.
  4. Chen, L. and Letchford, C.W. (2004), "A deterministic-stochastic hybrid model of downbursts and its impact on a cantilevered structure", Eng. Struct., 26(5), 619-629. https://doi.org/10.1016/j.engstruct.2003.12.009
  5. Fujita, T.T. (1985), "The downburst : Microburst and Macroburst: Report of projects NIMROD and JAWS", University of Chicago.
  6. Holmes, J.D. (2008), "Recent developments in the specification of wind loads on transmission lines", J. Wind Eng., 5(1), 8-18.
  7. Holmes, J.D. and Oliver, S.E. (2000), "An empirical model of a downburst", Eng. Struct., 22(9), 1167-1172. https://doi.org/10.1016/S0141-0296(99)00058-9
  8. Holmes, J.D., Baker, C.J., English, E.C. and Choi, E.C.C. (2005), "Wind structure and codification", Wind Struct., 8(4), 235-250. https://doi.org/10.12989/was.2005.8.4.235
  9. Huang, B.C. and Wang, C.J. (2008), The Wind Resistance Analysis Principle and Application in Structure, Tongji University Press, Shanghai, China.
  10. International Electrotechnical Commission(2003), Design criteria of overhead transmission lines, Geneva, Switzerland.
  11. Li, C.X., Li, J.H. and Yu, Z.Q. (2009), "A review of wind-resistant design theories of transmission tower-line system", J. Vib. Shock, 28(10), 15-25.
  12. Lou, W.J., Wang, X. and Jiang, Y. (2009), "Wind-induced responses of a high-rise transmission tower to thunderstorm downbursts", Proceedings of the 7 th Asia-Pacific Conference on Wind Engineering, Taipei.
  13. Magdi F.Ishac and H.Brian White (1995), "Effect of tornado loads on transmission lines", IEEE T. Power Deliver., 10(1), 445-451. https://doi.org/10.1109/61.368368
  14. Mara, T.G., Hong, H.P., Lee, C.S. and Ho, T.C.E. (2016), "Capacity of a transmission tower under downburst wind loading", Wind Struct., 22(1), 65-87. https://doi.org/10.12989/was.2016.22.1.065
  15. National Energy Administration (2012), Technical regulation of design for tower and pole structures of overhead transmission line DL/T 5154-2012, Beijing, China.
  16. Oseguera, R.M. and Bowles, R.L. (1988), "A simple analytic 3-dimensional downburst model based on boundary layer stagnation flow", NASA Technical Memorandum 100632.
  17. Qu, W.L. and Ji, B.F. (2013), Formation and Diffusion of Downburst and Disaster Effect on Transmission Line", Science Press, Beijing, China.
  18. Savory, E., Parke, G.A.R., Zeinoddini, M., Toy, N. and Disney, P. (2001), "Modelling of tornado and microburst-induced wind loading and failure of a lattice transmission tower", Eng. Struct., 23(4), 365-375. https://doi.org/10.1016/S0141-0296(00)00045-6
  19. Shehata, A.Y., El Damattya, A.A. and Savory, E. (2005), "Finite element modeling of transmission line under downburst wind loading", Finite Elem. Anal. Des., 42(1), 71-89. https://doi.org/10.1016/j.finel.2005.05.005
  20. Vicroy, D.D. (1991), A Simple, Analytical, Asymmetric Microburst Model for Downdraft Estimation, NASA Technical Memorandum 104053.
  21. Wang, J.W. and Qu, W.L. (2009), "Analysis on the destroyed features of tower-line structures under downburst", Proceedings of the 14th national conference on structural wind engineering, Beijing.
  22. Wood, G.S. and Kwok, K.C.S. (1998), "An empirically derived estimate for the mean velocity profile of a thunderstorm downburst", Proceedings of the 7th AWES Workshop, Aukland.

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