Ambient Vibration Testing of Existing Buildings in Madinah

Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail

Abstract:

The elastic period has a primary role in the seismic assessment of buildings. Reliable calculations and/or estimates of the fundamental frequency of a building and its site are essential during analysis and design process. Various code formulas based on empirical data are generally used to estimate the fundamental frequency of a structure. For existing structures, in addition to code formulas and available analytical tools such as modal analyses, various methods of testing including ambient and forced vibration testing procedures may be used to determine dynamic characteristics. In this study, the dynamic properties of the 32 buildings located in the Madinah of Saudi Arabia were identified using ambient motions recorded at several, spatially-distributed locations within each building. Ambient vibration measurements of buildings have been analyzed and the fundamental longitudinal and transverse periods for all tested buildings are presented. The fundamental mode of vibration has been compared in plots with codes formulae (Saudi Building Code, EC8, and UBC1997). The results indicate that measured periods of existing buildings are shorter than that given by most empirical code formulas. Recommendations are given based on the common design and construction practice in Madinah city.

Keywords: Ambient vibration, Fundamental period, RC buildings, Infill walls.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1099948

References:

[1] Applied Technology Council, Tentative provisions for the development of seismic regulations for buildings, Report No. ATC3-06, Applied Technology Council, Palo Alto, California, 1978.
[2] UBC1997, "Uniform building Code" International Conference of Building Officials, USA, 1997.
[3] Eurocode 8, (EC8-2006), "Design of structures for earthquake resistance", Part 1: General rules, seismic actions and rules for buildings, ComiteEuropeen de Normalisation, Brussels, 2006.
[4] Saudi Building Code - Structural requirements for Loads and Forces - SBC 301 (2007).
[5] M.R. Gallipoli, M. Mucciarelli, M. Vona,"Empirical estimate of fundamental frequencies and damping for Italian buildings". Earthquake Engineering and Structure Dynamic Vol. 38, pp. 973–988, DOI: 10.1002/eqe.878, 2009.
[6] H. Crowley, and R. Pinho, "Revisiting Eurocode 8 formulae for periods of vibration and their employment in linear seismic Analysis" Earthquake Engineering and Structural Dynamics; Vol. 39 No. 2, pp. 223–235, DOI: 10.1002/eqe.949, 2010.
[7] N. Al-Nimry, M. Resheidat, and M. Al-Jamal, "Ambient vibration testing of low and medium rise in-filled RC frame buildings in Jordan", Soil Dynamics and Earthquake Engineering Vol. 59, pp. 21–29, DOI: 10.1016/j.soildyn.2014.01.002, 2014.
[8] S. Midorikawa, “Ambient vibration test of buildings in Santiago and Viña del Mar”, A report on the Chile-Japan joint study project on seismic design of structures, The Japan international cooperation agency, 1990.
[9] C. NegulescuR. Radoi, A. Aldea,"Microtremor measurement for evaluation of building vibration characteristics", Report, National Center for Seismic Risk Reduction, Bucharest, Part 1 - 23p. and Part 2, 20p, 2004.
[10] C. Michel, P. Guéguen., P. Y. Bard, "Dynamic parameters of structures extracted from ambient vibration measurements", an aid for the seismic vulnerability assessment of existing buildings in moderate seismic hazard regions, Soil Dynamics and Earthquake Engineering; Vol. 28 , No.8, pp. 593-604, 2008.
[11] S. Demetriuand A. Aldea, "Modal parameters of RC frame structure identified from ambient vibration measurements" 15 WCEE, Lisbona, 2012.
[12] R. Crawford and H. S. Ward, “Determination of the Natural Periodof Buildings,” Bulletin of the Seismological Society of America, Vol. 54, No. 6, pp. 1743-1756, 1964.
[13] M. D. Trifunac, “Comparison between Ambient and Forced Vibration Experiments,” Earthquake Engineering and Structural Dynamics, Vol. 1, pp. 133-150, 1972.
[14] B. Peeters, F. Vanhollebekeand H. Van der Auweraer, “Operational Polymax for Estimating the Dynamic Properties of a Stadium Structure During a Football Game,” Proc. 23rd Int. Modal Analysis Conference, Orlando, FL, 2005.
[15] ASCE 7-10, "Minimum Design Loads for Buildings and Other Structures", Published by the American Society of Civil Engineers, ASCE/SEI 7-10, 2010.