Experimental Study on Vibration Transfer from Shaking Table to the Surrounding Environment

Document Type : Research Article

Authors

1 Structural Engineering Research Center,International Institute of Earthquake Engineering and Seismology,Tehran,Iran

2 Structural Engineering Research Center,International Institute of Earthquake Engineering and Seismology

Abstract

Interaction study on shaking tables is considered necessary for such devices to guarantee their operational accuracy in vibration simulation. In such studies, accurate estimation of dynamic characteristics of the foundation of shaking tables and their neighboring soil is usually required. In this regard, experimental studies on the soil or the foundation after its completion are recommended to reduce uncertainties in the operation of the table in near future. In this work, a forced vibration study on the foundation of a six degrees of freedom shaking table (to be operated by the international institute of earthquake engineering and seismology) has been performed. In addition to the measured excitation information collected for the determination of dynamic characteristics of the foundation, that part of the vibration that transfers to the soil (at different distances from the foundation) was also evaluated. Based on the results of such measurements, dynamic characteristics of the shaking table foundation using a single degree of freedom model are estimated. Later the magnitude and the frequency contents of the vibration that was transferred to the soil in distances up to 25 meters from the edge of the foundation (in both vertical and horizontal directions) were also determined. According to the results of this study, the level of transferred acceleration to the soil reduces, rapidly, by distance from the foundation. However, the results of these measurements indicate that acceleration magnitude in the range of high-frequency vibration remains untouched.

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[1] Luco, J. E, Ozcelik, O., Conte, J. P., & Mendoza, L. "Experimental study of the dynamic interaction between the foundation of the NEES/UCSD Shake Table and the surrounding soil: Reaction block response." Soil Dynamics and Earthquake Engineering 31.7 (2011): 954-953.
[2] Soltani, Behroz. Soil-structure interaction in massive foundations. M.S. Thesis. International Institute of Earthquake Engineering and Seismology, 2015.
[3] Wolf, John P. Dynamic Soil-Structure Interaction. Vol. 1. Englewood: Prentice-Hall, 1985.
[4] Nabati, Farzaneh. Sensitivity analysis of a shaking table subjected to interaction with surrounding environment. M.S. Thesis. International Institute of Earthquake Engineering and Seismology, 2015.
[5] Clough, R. W., and Penzien, J., Dynamics of Structures, Second Edition, McGraw-Hill. Inc., New York, NY, 1993.