DOI QR코드

DOI QR Code

Relationships for prediction of backstay effect in tall buildings with core-wall system

  • Received : 2019.02.10
  • Accepted : 2019.09.28
  • Published : 2020.01.25

Abstract

One of the prevailing structural systems in high-rise buildings is the core-wall system. On the other hand, the existence of one or more underground stories causes the perimeter below-grade walls with the diaphragm of grade level to constitute of a very stiff box. In this case or a similar situation, during the lateral response of a tall building, underground perimeter walls and diaphragms that provide an increased lateral resistance relative to the core wall may introduce a prying action in the core that is called backstay effect. In this case, a rather great force is generated at the diaphragm of the grade-level, acting in a reverse direction to the lateral force on the core-wall system, and thus typically causes a reverse internal shear. In this research, in addition to review of the results of the preceding studies, an improved relationship is proposed for prediction of backstay force. The new proposed relationship takes into account the effect of foundation flexibility and is presented in a non-dimensional form. Furthermore, a specific range of the backstay force to lateral load ratio has been determined. And finally, it is shown that although all suggested formulas are valid in the elastic domain, yet with some changes in the initial considerations, they can be applied to some certain non-linear problems as well.

Keywords

References

  1. Adebar, P. (2008), "Design of high-rise core-wall buildings: A Canadian perspective", Proceedings of the 14th World Conference on Earthquake Engineering, Beijing, China, October.
  2. Beiraghi, H., Kheyroddin, A. and Kafi, M.A. (2016), "Forward directivity near-fault and far-fault ground motion effects on the behavior of reinforced concrete wall tall buildings with one and more plastic hinges", Struct. Design Tall Special Buildings, 25(11), 519-539. https://doi.org/10.1002/tal.1270.
  3. Beiraghi, H. (2018a), "Energy demands in reinforced concrete wall piers coupled by buckling restrained braces subjected to near-fault earthquake", Steel Compos. Struct., 27(6), 703-716. https://doi.org/10.12989/scs.2018.27.6.703.
  4. Beiraghi, H. (2018b), "Energy dissipation of reinforced concrete wall combined with buckling-restrained braces subjected to near- and far-fault earthquakes", Iran. J. Sci. Technol., Transactions Civil Eng., 42(4), 345-359. https://doi.org/10.1007/s40996-018-0109-0.
  5. Beiraghi, H. (2018c), "Near-fault ground motion effects on the responses of tall reinforced concrete walls with buckling-restrained brace outriggers", Scientia Iranica, 25(4), 1987-1999. https://dx.doi.org/10.24200/sci.2017.4205.
  6. Beiraghi, H. (2018d), "Reinforced concrete core-walls connected by a bridge with buckling restrained braces subjected to seismic loads", Earthq. Struct., 15(2), 203-214. https://doi.org/10.12989/eas.2018.15.2.203.
  7. Beiraghi, H. (2017), "Earthquake effects on the energy demand of tall reinforced concrete walls with buckling-restrained brace outriggers", Struct. Eng. Mech., 63(4), 521-536. https://doi.org/10.12989/sem.2017.63.4.521.
  8. Beiraghi, H. and Siahpolo, N. (2016), "Seismic assessment of RC core-wall building capable of three plastic hinges with outrigger", Struct. Design Tall Special Buildings, 26(2), 1306-1325. https://doi.org/10.1002/tal.1306.
  9. Farghaly, A. A. (2016), "Seismic assessment of slender high rise buildings with different shear walls configurations", Adv. Comput. Design, 1(3), 221-234. https://doi.org/10.12989/acd.2016.1.3.221.
  10. Fu, F. (2018), Design and Analysis of Tall and Complex Structures, Elsevier Science, Cambridge, MA, USA.
  11. Fu, F. (2015), Advanced Modeling Techniques in Structural Design, Wiley, West Sussex, Chichester, UK.
  12. Gere, J.M. and Timoshenko, S.P. (1991), Mechanics of Materials, 3rd Edition, Springer, New York, USA.
  13. Karimi, M. and Kheyroddin, A. (2016), "Study of backstay effect in tall buildings and presentation of governed relationships of structural behavior from this standpoint", 2nd National Conference of Iranian structural Engineering, Tehran, Iran, February.
  14. Karimi, M., Kheyroddin, A. and Shariatmadar, H. (2018), "Study of Backstay Effect in Tall Buildings with Core Wall System by Involving of Shear Deformation", Bullet. Earthq. Sci. Eng., 5(3), 61-71.
  15. Kowalczyk, R.M., Sinn, R., Bennetts, I.D. and Kilmister, M.B. (1995), Structural Systems for Tall Buildings, Council on Tall Buildings and Urban Habitat, McGraw-Hill, New York, USA.
  16. LATBSDC (2017), An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region 2017 Edition, Los Angeles Tall Buildings Structural Design Council; Los Angeles, CA, USA.
  17. Moehle, J. (2015), Seismic Design of Reinforced Concrete Buildings, McGraw-Hill Education, New York, USA.
  18. PEER/ATC-72-1 (2010), "Modeling and Acceptance Criteria for Seismic Design and Analysis of Tall Buildings", PEER Rep. No. 2010/111, Pacific Earthquake Engineering Research Center, Berkeley, CA, USA.
  19. Rad, R.B. and Adebar, P. (2009), "Seismic design of high-rise concrete walls: Reverse shear due to diaphragms below flexural hinge", J. Struct. Eng., 135(8), 916-924. https://doi.org/10.1061/(ASCE)0733-9445(2009)135:8(916).
  20. Smith, B.S. and Coull, A. (1991), Tall Building Structures: Analysis and Design, John Wiley & Sons, New York, USA.
  21. Taranath, B.S. (2010), Reinforced Concrete Design of Tall Buildings, CRC Press, Taylor & Francis, Boca Raton, Florida, USA.
  22. TBI/PEER (2017), "Tall Building Initiative, Guidelines for Performance-Based Seismic Design of Tall Buildings", PEER 2017/06, Pacific Earthquake Engineering Research Center; Berkeley, CA, USA.
  23. Tocci, N. and Levi, S. (2012), "Basement modeling in tall buildings: Backstay effect", Structure Magazine, June, 23-24.