The motion of a building depends on the excitation, coupling to ground, and mechanical properties building. We separate response from excitation ground by deconvolving recorded at different levels in apply this recordings Robert A. Millikan Library Pasadena, California. This de- convolution allows for separation instrinsic attenuation radiation damping. waveforms obtained deconvolution with top floor show superposition one upgoing downgoing wave. basement can be formulated either as sum...

This study examines the rationale of Hilbert-Huang transform (HHT) for analyzing dynamic and earthquake motion recordings in studies seismology engineering. In particular, this paper first provides fundamentals HHT method, which consist empirical mode decomposition (EMD) Hilbert spectral analysis. It then uses to analyze hypothetical real wave motion, results are compared with obtained by Fourier data processing technique. The analysis two indicates that method is able extract some...

Dynamic property measurements of the moment-resisting steel-frame University California, Los Angeles, Factor building are being made to assess how forces distributed over building. Fourier amplitude spectra have been calculated from several intervals ambient vibrations, a 24-hour period strong winds, and 28 March 2003 Encino, California ( ML =2.9), 3 September 2002 Yorba Linda, =4.7), November Central Alaska Mw =7.9) earthquakes. Measurements vibration records show that first-mode frequency...

This paper presents a discrete-time wave-propagation method to calculate the seismic response of multistory buildings, founded on layered soil media and subjected vertically propagating shear waves. Buildings are modeled as an extension by considering each story another layer in path. The is expressed terms wave travel times between layers reflection transmission coefficients at interfaces. accounts for filtering effects concentrated foundation floor masses. Compared with commonly used...

A concise review of the fheory adaptive modeling, identification, and control dynamic structural systems based on discrete‐time recordings is presented. Adaptive methods have four major advantages over classical methods: (1) Removal noise from signal done whole frequency band; (2) time‐varying characteristics can be tracked; (3) with unknown controlled; (4) a small segment data needed during computations. Included in paper are representation single‐input single‐output (SISO) systems, models...

Most of the previous studies considered structural system identification in continuous‐time domain. The discrete‐time approach to problem is more natural since all recordings are form. This study presents a method for by using linear filters. itself well known electrical and systems engineering fields, therefore not new. objective paper present emphasising its relation familiar continuous‐domain modal analysis that widely used engineering. In addition method, some practical but important...

Soil-structure interaction (SSI) can significantly alter the characteristics of recorded motions in buildings. The dominant frequency a building subjected to SSI is always smaller than frequencies fixed-base building, and foundation when no present. A with noncausal system because coupling between superstructure. presence be detected by investigating causality building's impulse response. For causal systems, amplitudes response function at negative times are zero, whereas for systems they...

The paper presents a tutorial review of the models and methods that are used to characterize site amplification from pairs rock- soil-site records, introduces some new techniques with better theoretical foundations. discussed include spectral cross-spectral ratios, ratios for downhole response constant factors, parametric models, physical time-varying filters. An extensive analytical numerical error analysis shows probabilistically give more reliable estimates amplification. Spectral should...

This paper investigates the effects of seismic retrofitting on modal characteristics a 6-story RC building located in Istanbul, Turkey. Ambient vibration surveys were carried out before, during, and after work, which took place between June December 2010. The was retrofitted via jacketing columns, addition structural walls, construction mat foundation. These studies complemented with data from forced tests performed an eccentric-mass shaker work completed. During retrofitting, partitions...

A discrete-time analysis of seismic site amplification in layered media for vertically propagating shear waves is presented. The approach not only simpler and more accurate than the previously suggested frequency-domain techniques but also provides better physical insight into problem. domain equations wave propagation can be derived by using upgoing downgoing as auxiliary variables, require three parameters each layer: reflection coefficient at bottom layer, travel time damping. formulation...

Recently developed adaptive methods for modeling, identification, and control are now being successfully used in various branches of science engineering. These present significant advantages over the classical methods, e.g., they can remove noise from signal whole frequency band, track time‐varying characteristics systems, make it possible to unknown systems. In this paper, five examples application techniques structural dynamics presented. The as follows: (1) Identification a simulated...

The objective of this paper is to present preliminary analyses a set acceleration response records obtained during the October 17, 1989 Loma Prieta earthquake (Ms=7.1) from 60‐story vertically tapered, pyramid‐shaped Transamerica Building—a landmark San Francisco. building was instrumented in 1985 with 22 channels synchronized sensors consisting 13 uniaxial ac‐celerometers deployed throughout structure and connected central recording system three triaxial strong‐motion accelerographs at...

The objective of this paper is to present analyses a set acceleration response records obtained during the October 17, 1989 Loma Prieta earthquake (Ms=7.1) from 30‐story, three‐winged, ductile moment‐resistant reinforced‐concrete‐framed Pacific Park Plaza Building, located in Emeryville, east San Francisco, Calif. building was constructed 1983, and instrumented 1985 with 21 channels synchronized uniaxial accelerometers deployed throughout structure, three at free‐field outside on north side...

A detailed analysis of the recorded seismic response Transamerica Building during October 17, 1989 Loma Prieta earthquake is presented. The system identification algorithm used for based on discrete‐time linear filtering approach with least‐squares approximation, and assumes a multi‐input, single‐output model building. Fifteen modes in north‐south direction, 18 east‐west direction are identified from records. shows that building's to was dominated by coupled mode vibration at 0.28 Hz...

Analyses of recordings include processing data, determining analytical models that match the record, and identification system from which record is obtained.Current methods are used to analyze in structural engineering based on classical filtering Fourier analysis approach.These assume that: (a) either signal noise spectra nonoverlapping, or there a frequency band where ratio high (i.e., can be neglected), (b) properties within selected time window time-invariant.Recently, new for have been...

This is the second of two companion papers on recorded seismic response Pacific Park Plaza building, in Emeryville, Calif., during October 17, 1989, Ms=7.1 (surface‐wave magnitude) Loma Prieta earthquake. In this part, data are analyzed more detail by using system‐identification techniques. The three‐dimensional behavior and coupled modes building determined, effects soil‐structure interaction investigated. study shows that nonlinear at beginning, becomes linear after 17 sec into dominant...

SUMMARY This paper presents the variations of vibration under different traffic conditions on Fatih Sultan Mehmet suspension bridge in Istanbul, Turkey.The main intention is to determine amplifications heavy‐traffic as opposed no‐traffic conditions. first study this particular area that has been performed bridge, over which an average 200,000 cars pass daily. Two full‐scale ambient surveys were carried out two days response diverse Initial measurements taken experienced heavy stress caused...