An attempt of real-time structural response assessment by an interferometric approach: A tailor-made earthquake early warning for buildings

Abstract Earthquake early warning systems (EEWS) are considered an effective and viable tool for seismic risk reduction in cities. Innovative directions for the development of novel EEWS include designing new methods for structure specific EEWS, where regional and on-site networks of seismic stations and seismological and earthquake-engineering knowledge and experience are combined. Furthermore, the design of novel EEWS can nowadays take advantage of recent technological advances involving the development of low-cost networks of wireless accelerometric stations. In this work we present a first attempt at designing a structure specific EEW procedure, which is based on the analysis of early P-wave signals recorded by wireless accelerometers placed at different levels of a structure. The procedure exploits the interferometric analysis of the recorded P-wave signals to obtain the response of the structure with respect to an impulsive input signal. This latter piece of information can be combined with an estimation of the incoming event size in order to obtain a real-time early assessment of the structural response at the different structure's levels. The procedure, named Tailor-made Earthquake Early Warning (TEEW), is composed of four steps: (1) The early event characterization through the inversion of the accelerometer spectra recorded at the base of the structure, (2) the early building response estimation through the deconvolution of P-wave signals recorded at selected levels of the structure, (3) the estimation of the expected shaking at the different levels through the convolution of the results from steps (1) and (2), and (4) a simple decisional rule based on the exceedance of a threshold value of the early estimation of the inter-story drift (i.e. the relative horizontal displacement of two adjacent floors in a building, expressed as a percentage of the story height separating the two adjacent floors) to determine whether or not to issue an alarm. A first test of the TEEW procedure is presented using recordings of three aftershocks of the L'Aquila sequence in 2009 that have been collected at the city hall of Navelli, Italy.

[1]  Yih-Min Wu,et al.  Development of an Earthquake Early Warning System Using Real-Time Strong Motion Signals , 2008, Sensors.

[2]  Marco Vona,et al.  Real time monitoring of structures in task force missions: the example of the Mw = 6.3 Central Italy Earthquake, April 6, 2009 , 2010 .

[3]  Angelo Masi,et al.  Far field damage on RC buildings: the case study of Navelli during the L’Aquila (Italy) seismic sequence, 2009 , 2011 .

[4]  H. Kanamori,et al.  The Potential for Earthquake Early Warning in Southern California , 2003, Science.

[5]  R. Clough,et al.  Dynamics Of Structures , 1975 .

[6]  Shunroku Yamamoto,et al.  On the estimation of seismic intensity in earthquake early warning systems , 2008 .

[7]  Hiroo Kanamori,et al.  Earthquake early warning: Concepts, methods and physical grounds , 2011 .

[8]  Rocco Ditommaso,et al.  A fast method for structural health monitoring of Italian reinforced concrete strategic buildings , 2010 .

[9]  Yih‐Min Wu,et al.  An examination of τc-Pd earthquake early warning method using a strong-motion building array , 2011 .

[10]  J. Brune.  Tectonic stress and the spectra of seismic shear waves from earthquakes , 1970 .

[11]  Peter Bormann,et al.  New Relationships between Vs, Thickness of Sediments, and Resonance Frequency Calculated by the H/V Ratio of Seismic Noise for the Cologne Area (Germany) , 2002 .

[12]  Erdal Şafak,et al.  Discrete-Time Analysis of Seismic Site Amplification , 1995 .

[13]  Gaetano Manfredi,et al.  REAL-TIME RISK ANALYSIS FOR HYBRID EARTHQUAKE EARLY WARNING SYSTEMS , 2006 .

[14]  C. Milkereit,et al.  Wireless technologies for the monitoring of strategic civil infrastructures: an ambient vibration test on the Fatih Sultan Mehmet Suspension Bridge in Istanbul, Turkey , 2010 .

[15]  H. Kanamori,et al.  A moment magnitude scale , 1979 .

[16]  S. Parolai,et al.  The Importance of Converted Waves in Comparing H/V and RSM Site Response Estimates , 2004 .

[17]  Iunio Iervolino,et al.  Performance-based earthquake early warning , 2011 .

[18]  John G. Anderson,et al.  A MODEL FOR THE SHAPE OF THE FOURIER AMPLITUDE SPECTRUM OF ACCELERATION AT HIGH FREQUENCIES , 1984 .

[19]  Iunio Iervolino,et al.  Foreword to: Prospects and applications of Earthquake Early Warning for real-time earthquake engineering, risk management and loss mitigation , 2011 .

[20]  Gaetano Festa,et al.  Earthquake magnitude estimation from early radiated energy , 2008 .

[21]  Gaetano Manfredi,et al.  Uncertainty in early warning predictions of engineering ground motion parameters : What really matters? , 2009 .

[22]  H. Engl,et al.  Regularization of Inverse Problems , 1996 .

[23]  Kiyoshi Kanai,et al.  Some New Problems of Seismic Vibrations of a Structure. Part 1. , 1963 .

[24]  Marco Vona,et al.  Interferometric Analysis of Strong Ground Motion for Structural Health Monitoring: The Example of the L’Aquila, Italy, Seismic Sequence of 2009 , 2011 .

[25]  Lucia Luzi,et al.  The Mw 6.3, 2009 L’Aquila earthquake: source, path and site effects from spectral analysis of strong motion data , 2009 .

[26]  Mihailo D. Trifunac,et al.  Earthquake damage detection in the Imperial County Services Building III: Analysis of wave travel times via impulse response functions , 2008 .

[27]  Thomas H. Heaton,et al.  The Virtual Seismologist (VS) Method: a Bayesian Approach to Earthquake Early Warning , 2007 .

[28]  An evolutionary approach to real‐time moment magnitude estimation via inversion of displacement spectra , 2011 .

[29]  Hiroo Kanamori,et al.  Real-Time Seismology and Earthquake Damage Mitigation , 2005 .

[30]  Richard M. Allen,et al.  The Status of Earthquake Early Warning around the World: An Introductory Overview , 2009 .

[31]  Yoshiaki Hisada,et al.  Application of an earthquake early warning system and a real-time strong motion monitoring system in emergency response in a high-rise building , 2011 .

[32]  Roel Snieder,et al.  Extracting the Building Response Using Seismic Interferometry: Theory and Application to the Millikan Library in Pasadena, California , 2006 .

[33]  Li Zhao,et al.  Magnitude estimation using the first three seconds P‐wave amplitude in earthquake early warning , 2006 .

[34]  Yang Wang,et al.  Performance monitoring of the Geumdang Bridge using a dense network of high-resolution wireless sensors , 2006, Smart Materials and Structures.

[35]  Can Zulfikar,et al.  The Self-organizing Seismic Early Warning Information Network (SOSEWIN) , 2009 .

[36]  Aldo Zollo,et al.  Earthquake magnitude estimation from peak amplitudes of very early seismic signals on strong motion records , 2006 .

[37]  Giovanna Cultrera,et al.  Separation of source and site effects by generalized inversion technique using the aftershock recordings of the 2009 L’Aquila earthquake , 2011 .

[38]  Paolo Gasparini,et al.  Earthquake early warning as a tool for improving society's resilience and crisis response , 2011 .

[39]  Mustafa Erdik,et al.  Istanbul Earthquake Rapid Response and the Early Warning System , 2003 .