Damage ratios for domestic buildings in the 1987 Edgecumbe earthquake

  • D. J. Dowrick DSIR Physics and Engineering Laboratory, Lower Hutt, New Zealand
  • D. A. Rhoades DSIR Applied Mathematics Division, Wellington, New Zealand


This paper describes an analysis of damage costs to house and farm property in the Ms = 6.6 Edgecumbe New Zealand earthquake of 2 March 1987. The study investigated damage ratios for dwellings, plus their associated garages and farm buildings. The damage costs were converted to damage ratios, by dividing them by the total value of the relevant property in the intensity zones concerned. The mean values and statistical distributions of these damage ratios were then found, the lognormal distribution fitting very well. The mean damage ratio for house buildings at MM intensity IX was 0.08, and the mean damage ratios were generally smaller than previous studies had shown.


NZ Jnl Geol Geoph, Special Edgecumbe earthquake issue, 1 (1989).

D.J. Oowrick, "Damage costs for houses and farms as a function of intensity in the 1987 Edgecumbe earthquake", submitted to Earthquake Engineering and structural Dynamics.

M.A. Lowry, S.C. Ede, and J.S. Harris, "Assessment of seismic intensities resulting from the 1987 Edgecumbe earthquake, New Zealand, and implications for modernising the intensity scale", New Zealand Jnl of Geology and Geophysics, 32, 145-153, (1989). DOI: https://doi.org/10.1080/00288306.1989.10421398

D. J. Dowrick, "A study of earthquake liabilities for the New Zealand South British Insurance Company", unpublished report by Brickell Moss & Partners (1981).

G.R. Birss, "Methodology for the assessment of the damage cost resulting from a large earthquake in the vicinity of Wellington", Bulletin NZ National society for Earthquake Eng., 18, 215- 223, (1985).

R.C. Cooney, and A.H.R. Fowkes, "New Zealand houses in earthquakes - What will happen?", in Large Earthquakes in New Zealand, The Royal Society of New Zealand, 101-109, (1981).

C. Rojan and R. L. Sharpe, "Earthquake damage evaluation data", ATC-13, Applied Technology Council, California, 1985.

R. C. Cooney, "The structural performance of houses in earthquakes", Proc. 2nd South Pacific Reg. Conf. on Earthquake Eng., Wellington, 2, 325- 351, 1979.

"Building Conf relating to the use of timber in building construction", Wellington, Govt Print, 1924 (NZ State Forest Service Circular No.14).

NZS 95-1936. New Zealand standard model building by-law. Sections I-X. Standards Association of New Zealand.

NZSS 95. New Zealand standard code of building by-laws. Standards Association of New Zealand (Part IX - Light Timber Construction, Feb. 1944; Part XII - Chimneys, July, 1951).

NZSS 1900: 1964. New Zealand standard model building by-law. Standards Association of New Zealand (Chapter 6, Division 6.1 and Chapter 7.)

NZS 3604:1978. Code of practice for light timber frame buildings not requiring specific design. Standards Association of New Zealand.

D. J. Dowrick, "Attenuation of Modified Mercalli intensity in New Zealand earthquakes", (in preparation).

How to Cite
Dowrick, D. J., & Rhoades, D. A. (1990). Damage ratios for domestic buildings in the 1987 Edgecumbe earthquake. Bulletin of the New Zealand Society for Earthquake Engineering, 23(2), 137-149. https://doi.org/10.5459/bnzsee.23.2.137-149