Comparison of New Zealand standards used for seismic design of concrete buildings
Major changes have occurred over the last six decades in New Zealand design codes for seismic resistance of structures. This paper describes the changes in the required design strengths, stiffness levels and capacity design provisions with particular reference to buildings where the lateral force resistance is provided by reinforced concrete moment resisting frames. It is shown that simple comparisons of response spectra and limiting inter-storey drifts can give misleading conclusions regarding relative strength and stiffness requirements unless allowance is made for many other interacting factors. To illustrate this, minimum design requirements defined in codes (or standards) over the last six decades are compared with the corresponding 2009 design requirements for regular buildings in which the lateral force resistance is provided by moment resisting frames. The approach that is described can be applied to other forms of structure. The paper is intended to provide background information for engineers planning to assess the need for seismic retrofit of existing buildings and to show the different factors which should to be considered in assessing existing structures against current design criteria.
Standards New Zealand, “NZS 1170.5:2004, Structural Design Actions, Part 5, Earthquake Actions New Zealand”.
Standards New Zealand, “NZS 3101:2006, Concrete Structures Standard”.
New Zealand Standards Institute, “NZSS 95, Pt. IV, Basic Loads to be Used in Design and Their Methods of Application”, Mar. 1955.
Andrews A.L., “Before Beginning”, Published NZSEE, 2008.
British Standards Institution, CP 114:1957, “The Structural Use of Reinforced Concrete in Buildings”, 1957.
New Zealand Standards Institute, NZSS 1900, Chapter 8: “Basic Design Loads”, 1965.
New Zealand Standards Institute, “NZSS 1900, Chapter 9.3, Design and Construction, Concrete”, 1964.
Ministry of Works, “Code of Practice, Design of Public Buildings”, Office of Chief Structural Engineer, May 1970.
American Concrete Institute, “ACI Standard, Building Code Requirements for Reinforced Concrete, (ACI 318-71), Detroit Michigan, 1971.
Standards Association New Zealand, “NZS 4203:1976, Code of Practice for General Structural Design and Design Loadings for Buildings”.
Blakeley, R.W.G. “A review of the new code provisions for separation of elements and buildings”, Bulletin of NZNSEE, Vol. 7, No. 3, September 1974.
Standards Association New Zealand, “NZS 4203:1984, Code of Practice for General Structural Design and Design Loadings for Buildings”.
Standards Association of New Zealand, “NZS 3101:1982, Code of Practice for Design of Concrete Structures”.
Paulay, T., “Column, evaluation of actions”, Bulletin NZNSEE, Vol. 10, No. 2, June 1977, pp 85-94.
Standards New Zealand “NZS 4203:1992, Code of Practice for General Structural Design and Design Loadings for Buildings”.
Fenwick, R.C., Davidson, B.J. and Chung, B.T., "P-delta actions in seismic resistant structures", Bulletin NZ National Society for Earthquake Engineering, Vol. 25, No.1, Mar. 1992. pp. 56-69.
Ruiz, J.A.F., “Performance of ductile reinforced concrete moment resisting frames subjected to earthquake actions”, University of Canterbury, Civil Engineering Report No. 2006/1, pp239.
Standards New Zealand, “NZS 3101: 1995, Concrete Structures Standard”.
ICBO, 1997, “Uniform Building Code, 97”, Vol. 2, International Conference of Buildings Officials, Whittier, CA.
Stannard, M., Bialostocki, R., Hopkins, D.C., Jury, R. and Saunders, D., “Hollow core floors – a regulator’s perspective”, paper no. 07, NZSEE Conference, March 2007.
Fenwick, R., Lau D. and Davidson B.J.,“A comparison of the seismic design requirements in the New Zealand loadings standard with other major design codes”, NZSEE Bulletin, Vol.35, No.4, Sept. 2002, pp190-203.
Copyright (c) 2009 Richard Fenwick, Gregory MacRae
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