Identification of structural and soil properties from vibration tests of the Hualien containment model

Abstract

SUMMARYMeasurements of the response of the 1 4 -scale reinforced concrete Hualien (Taiwan) containment model obtained during forced vibration tests are used to identify some of the characteristics of the superstructure and the soil. In particular, attempts are made to determine the ÿxed-base modal frequencies, modal damping ratios, modal masses and participation factors associated with translation and rocking of the base. The shell superstructure appears to be softer than could have been predicted on the basis of the given geometry and of test data for the properties of concrete. Estimates of the shear-wave velocity and damping ratio in the top layer of soil are obtained by matching the observed and theoretical system frequency and peak amplitude of the response at the top of the structure. The resulting models for the superstructure and the soil lead to theoretical results for the displacement and rotations at the base and top of the structure which closely match the observed response.

Input and system identification of the Hualien soil–structure interaction system using earthquake response data

“…The Hualien LSST is an international joint research e ort among researchers from Taiwan, Japan, U.S.A., France and Korea for investigation of the SSI e ects during strong earthquake events and also for veriÿcation of the SSI computer analysis programs developed by the participants [7][8][9][10][11][12][13][14][15]. A Earthquake Engng Struct.…”

“…2003;32:1955-1975 the seismic activity is high. At ÿrst a series of forced vibration tests were conducted [7], and the test results were used to improve the properties of the analysis model for the soil and structure [13][14][15]. The ground accelerations and structural responses were then measured during several subsequent earthquake events.…”

Evaluation of soil-structure interaction effects from system identification of structures subject to forced vibration tests

“…Many such experiments to evaluate vibration properties of structures have been performed (e.g., [3,4,5,6,7]). Applications of forced vibration testing in which the data interpretation considers SSI effects are relatively limited, but have been undertaken to investigate system performance and its predictability (e.g., Millikan library, [8]; Lotung and Hualien containment models, [9,10], model structure [11]) and foundation impedance (Millikan library, [12]; model structures, [1,13]). Luco et al [12] developed two approaches to estimate fundamental-mode frequencies and damping ratios for the fixed-base condition using nonparametric system identification procedures, which is discussed further below.…”

“…Luco et al [12] developed two approaches to estimate fundamental-mode frequencies and damping ratios for the fixed-base condition using nonparametric system identification procedures, which is discussed further below. Those procedures are extended in Luco and de Barros [10] by applying parametric methods that estimate fixed base properties of the structure by fitting observed equivalent fixed-base displacements to equations for those displacements derived from theoretical models.…”

A survey of geotechnical system identification techniques

“…SASW technique was pioneered by Stokoe and coworkers [69,90] and developed further by Stokoe and others [70,83,101]. Forced-vibration tests of foundations were employed by Luco and Wong [64,65] to identify lowstrain stiffness and damping properties of underlying soil strata. The identifications were based on a minimization of differences between theoretical impedance functions [4] and those directly computed using forced-vibration results.…”