Economic payback of improved detailing for concrete buildings with precast hollow-core floors
A seismic financial risk analysis of typical New Zealand reinforced concrete buildings constructed with topped precast concrete hollow-core units is performed on the basis of experimental research undertaken at the University of Canterbury over the last five years. An extensive study that examines seismic demands on a variety of multi-storey RC buildings is described and supplemented by the experimental results to determine the inter-storey drift capacities of the buildings. Results of a full-scale precast concrete super-assemblage constructed and tested in the laboratory in two stages are used. The first stage investigates existing construction and demonstrates major shortcomings in construction practice that would lead to very poor seismic performance. The second stage examines the performance of the details provided by Amendment No. 3 to the New Zealand Concrete Design Code NZS 3101:1995. This paper uses a probabilistic financial risk assessment framework to estimate the expected annual loss (EAL) from previously developed fragility curves of RC buildings with precast hollow core floors connected to the frames according to the pre-2004 standard and the two connection details recommended in the 2004 amendment. Risks posed by different levels of damage and by earthquakes of different frequencies are examined. The structural performance and financial implications of the three different connection details are compared. The study shows that the improved connection details recommended in the 2004 amendment give a significant economic payback in terms of drastically reduced financial risk, which is also representative of smaller maintenance cost and cheaper insurance premiums.
Norton, J.A, King, A.B, Bull, D.K, Chapman, H.E, McVerry, G.H, Larkin, T.J, Spring, K.C, December 1994, “Northridge Earthquake Reconnaissance Report”, Bulletin of the New Zealand National Society for Earthquake Engineering, Vol. 27, No.4. DOI: https://doi.org/10.5459/bnzsee.27.4.235-344
Matthews, J. G., Lindsay, R., Mander, J. B. and Bull, D. 2005. “The seismic fragility of precast concrete buildings”, ICOSSAR 2005, Millpress, Rotterdam, pp 247-254.
Lindsay, R., Mander, J. B. and Bull, D.K. 2004. “Experiments on the seismic performance of hollow-core floor systems in precast concrete buildings”, 13th World Conference on Earthquake Engineering, Vancouver, B.C., Canada, August 1-6, 2004, Paper No. 285.
Krawinkler H. and Miranda E., 2004, “Performance- Based Earthquake Engineering”, Earthquake Engineering: From Engineering Seismology to Performance-Based Engineering, edited by Bozorgnia Y. and Bertero V.V. CRC Press, Boca Raton, FL. DOI: https://doi.org/10.1201/9780203486245.ch9
Dhakal, R. P. and Mander, J. B. 2005. “Probabilistic Risk Assessment Methodology Framework for Natural Hazards”, Report submitted to Institute of Geological and Nuclear Science (IGNS), Department of Civil Engineering, University of Canterbury, Christchurch, New Zealand.
Matthews J.G. 2004, “Hollow-core floor slab performance following a severe earthquake.” Ph.D Thesis, University of Canterbury, Christchurch, New Zealand.
Lindsay, R., 2004, “Experiments on the seismic performance of hollow-core floor systems in precast concrete buildings”, ME Thesis, University of Canterbury, Christchurch, New Zealand.
MacPherson, C., 2005. “Seismic performance and forensic analysis of a precast concrete hollow-core floor super-assemblage” ME Thesis, University of Canterbury, Christchurch, New Zealand.
NZS3101:1995, Standards New Zealand, 1995, “Concrete Structures Standard, NZS 3101, Parts 1 & 2”, Standards New Zealand.
NZS3101:2004, Amendment 3 to NZS3101:1995, Standards New Zealand, 1995, “Concrete Structures Standard, NZS 3101, Parts 1 & 2”, Standards New Zealand.
HAZUS. 1999, “Earthquake Loss Estimation Methodology”. Technical Manual. Prepared by the National Institute of Building Sciences for Federal Emergency Management Agency, Washington, DC.
Cornell C.A., Jalayer F., Hamburger R.O. and Foutch D.A., 2002, “Probabilistic Basis for 2000 SAC Federal Emergency Management Agency Steel Moment Frame Guidelines”, Journal of Structural Engineering, ASCE, Vol.128 No.4, pp 526-533. DOI: https://doi.org/10.1061/(ASCE)0733-9445(2002)128:4(526)
Lupoi G, Lupoi A and Pinto P.E, 2002, “Seismic Risk Assessment of RC Structures with the “2000 SAC/FEMA” Method”, Journal of Earthquake Engineering, Vol. 6, No. 4, pp 499-512. DOI: https://doi.org/10.1080/13632460209350427
Dutta A, 1999, “On Energy-Based Seismic Analysis and Design of Highway Bridges”, Ph.D Dissertation, Science and Engineering Library, State University of New York at Buffalo, Buffalo, NY.
Kennedy, R.P, Cornell, C.A, Campbell R.D, Kaplan, S and Perla H.F, 1980, “Probabilistic Seismic Safety Study of an Existing Nuclear Power Plant”, Nuclear Engineering and Design No. 59, pp 315-338. DOI: https://doi.org/10.1016/0029-5493(80)90203-4
NZS4203:1992, “Code of practice for general structural loading for buildings”, Standards New Zealand, Wellington, New Zealand.
Der Kiureghian A., 2005, “Non-erogodicity and PEER.s framework formula”, Earthquake Engineering and Structural Dynamics, Vol. 34, No. 13, pp 1643-1652. DOI: https://doi.org/10.1002/eqe.504