Seismic assessment of out-of-plane loaded unreinforced masonry walls in multi-storey buildings
A procedure is proposed to evaluate the dynamic out-of-plane stability of cracked unreinforced masonry (URM) walls located in multi-storey URM buildings. The equations of dynamic motion are derived from first principles and representative single-degree-of-freedom (SDOF) models are proposed. The models have nonlinear stiffness properties that correspond to the restoring gravitational forces. A method is suggested to transform the nonlinear problem to a corresponding linear equivalent so that conventional spectral methods can be used to calculate wall response.
The dynamic interaction between the URM building as the main structural system and the out-of-plane loaded walls as secondary elements is addressed by developing floor response spectra. Several buildings were assumed in a parametric study and subjected to code-compatible ground motion records. The absolute acceleration response at floor levels was calculated and the response spectra for that modified acceleration were subsequently obtained.
The results from the study suggest that modifications should be made to the equations proposed for the Parts response spectra in the New Zealand seismic loading standard, NZS 1170.5:2004, in order to calculate the spectral response of out-of-plane loaded URM walls. Several worked examples are presented to demonstrate application of the procedure.
Vaculik, J. (2012). Unreinforced masonry walls subjected to out-of-plane seismic actions. Ph.D. Thesis, School of Civil, Environmental, and Mining Engineering, The University of Adelaide.
ABK (1981). Methodology for mitigation of seismic hazards in existing unreinforced masonry buildings: Wall testing, out-of plane, ABK-TR-04. Technical report.
Priestley, M.J.N. (1985). Seismic behaviour of unreinforced masonry walls. Bulletin of the New Zealand National Society for Earthquake Engineering, 18(2):191–205.
Paulay, T. and Priestley, M.J.N. (1992), Seismic Design of Reinforced Concrete and Masonry Buildings, J. Wiley, New York. DOI: https://doi.org/10.1002/9780470172841
Simsir, C.C. (2004). Influence of diaphragm flexibility on the out-of-plane dynamic response of unreinforced masonry walls. Ph.D. Thesis, University of Illinois at Urbana-Champaign.
Costley, A.C. (1995). Dynamic response of URM buildings with flexible diaphragms. PhD Thesis, University of Illinois at Urbana-Champaign.
Tena-Colunga, A. (1992). Seismic evaluation of unreinforced masonry structures with flexible diaphragms. Earthquake Spectra, 8(2):305–318.
Penner O., Elwood, K. (2013). Shake table study on out-of-plane dynamic stability of unreinforced masonry walls. 12th Canadian Masonry Symposium, Vancouver, BC, Canada, June 02-05, 2013.
Penner, O. (2014). Effect of Diaphragm Flexibility on Out-Of-Plane Dynamic Stability of Unreinforced Masonry Walls. Ph.D. Thesis, The University of British Columbia.
Giongo, I., Wilson, A., Dizhur, D., Derakhshan, H., Tomasi, R., Griffith, M., Quenneville, P., Ingham, J. (2014). Detailed seismic assessment and improvement procedure for vintage flexible timber diaphragms, Accepted for publication in the Bulletin of the New Zealand Society for Earthquake Engineering, 47(2), June 2014, pp97-118. DOI: https://doi.org/10.5459/bnzsee.47.2.97-118
Sharif, I., Meisl, C.S. and Elwood, K.J. (2007). Assessment of ASCE 41 height-to-thickness ratio limits for URM walls. Earthquake Spectra, 23(4):893–908.
Housner, G.W. (1963). The behaviour of inverted pendulum structures during earthquakes, Bull. Seismol. Soc. Am. 53:403–417.
Makris, N. and Konstantinidis, D. (2003). The rocking spectrum and the limitations of practical design methodologies, Earthquake Eng. Struct. Dyn. 32:265– 289.
Doherty, K.T. (2000). An investigation of the weak links in the seismic load path of unreinforced masonry buildings. Ph.D. Thesis, Faculty of Engineering of The University of Adelaide.
Lam, N.T.K., Griffith, M., Wilson, J., Doherty, K. (2003). Time-history analysis of URM walls in out-of-plane flexure. Engineering Structures; 25(6):743–754.
Griffith, M.C., Magenes, G., Melis, G. and Picchi, L. (2003). Evaluation of out-of-plane stability of unreinforced masonry walls subjected to seismic excitation. Journal of Earthquake Engineering, 7(SPEC. 1):141–169.
Derakhshan, H., Griffith, M.C. and Ingham, J.M. (2013). Airbag testing of multi-leaf unreinforced masonry walls subjected to one-way bending, Engineering Structures, 57:512-522. DOI: https://doi.org/10.1016/j.engstruct.2013.10.006
Derakhshan, H., Dizhur D., Griffith, M.C. and Ingham, J.M. (2014). In-situ out-of-plane testing of as-built and retrofitted unreinforced masonry walls, ASCE J. of Struct. Eng., 140(6), 04014022. DOI: https://doi.org/10.1061/(ASCE)ST.1943-541X.0000960
Derakhshan, H., Griffith, M.C. and Ingham, J.M. (2013). "Out-of-plane behaviour of one-way spanning unreinforced masonry walls", ASCE J. Eng. Mech., 139(4), 409-417. DOI: https://doi.org/10.1061/(ASCE)EM.1943-7889.0000347
Walsh, K.Q., Dizhur, D.Y., Almesfer, N, Cummuskey, A., Cousins, J., Derakhshan, H., Griffith, M.C. and Ingham, J.M. (2014). Geometric Characterisation and Out-of-Plane Seismic Stability of Unreinforced Brick Masonry Buildings in Auckland, New Zealand. Bulletin of the New Zealand Society for Earthquake Engineering, 47(2), June 2014, pp139-156. DOI: https://doi.org/10.5459/bnzsee.47.2.139-156
BS (1992). BS5628.1:1992 Code of Practice for use of masonry; Part 1: Structural use of unreinforced masonry. British Standard.
Derakhshan, H. (2011). Seismic Assessment of Out-of-Plane Loaded Unreinforced Masonry Walls. Ph.D. Thesis, Faculty of Engineering, The University of Auckland.
NZSEE (2006). New Zealand Society for Earthquake Engineering (NZSEE): Assessment and Improvement of the Structural Performance of Buildings in Earthquakes. Recommendations of a NZSEE Study Group on Earthquake Risk Buildings.
Oyarzo-Vera, C.A., McVerry, G.H., Ingham, J.M. (2012). Seismic Zonation and Default Suite of Ground-Motion Records for Time-History Analysis in the North Island of New Zealand. Earthquake Spectra: 28(2):667-688.
NZS (2004). NZS 1170.5:2004: Structural Design Actions: Part 5: Earthquake actions, New Zealand. Standards New Zealand.
Shelton, R.H. (2004). “Seismic response of building parts and non-structural components.” Study report, No. 124. BRANZ, Porirua City 5381, New Zealand. ISSN: 0113-3675.
AS (2007). AS 1170.4:2007 Structural design actions, Part 4: Earthquake actions in Australia. Standards Australia.
Mazzon, N., Valuzzi, M.R., Aoki, T., Garbin, E., De Canio, G., Ranieri, G., Modena, C. (2009). Shaking table tests on two multi-leaf stone masonry buildings, 11th Canadian masonry Symposium, Toronto, Ontario, Canada, 31 May – 3 June.
University of Auckland (2011). Assessment and Improvement of Unreinforced Masonry Buildings for Earthquake Resistance, Draft 02/2011. Supplement to “NZSEE 2006 Assessment and Improvement of the Structural Performance of Buildings in Earthquakes”, Faculty of Engineering, University of Auckland.
Derakhshan, H., Ingham, J.M., and Griffith, M. (2009). Out-of-plane assessment of an unreinforced masonry wall: Comparison with the NZSEE recommendations. In Proceedings of the 2009 New Zealand Society for Earthquake Engineering Technical Conference, Christchurch, New Zealand, April 3-5.
AS (2011). AS 3700-2011: Masonry Structures. Standards Australia.
Wolf, J.P. (1985). Dynamic Soil–Structure Interaction. Prentice-Hall: Englewood Cliffs, NJ.
Copyright (c) 2014 Hossein Derakhshan, Dmytro Y. Dizhur, Michael C. Griffith, Jason M. Ingham
This work is licensed under a Creative Commons Attribution 4.0 International License.