Evidence of coupled soil-structure interaction and site response in continuous viaducts from ambient vibration tests

2019 ◽  
Vol 120 ◽  
pp. 408-422 ◽  
Author(s):  
Fabrizio Gara ◽  
Marco Regni ◽  
Davide Roia ◽  
Sandro Carbonari ◽  
Francesca Dezi
Keyword(s):  
Soil Structure ◽  
Site Response ◽  
Ambient Vibration ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Ambient Vibration Tests ◽  
Vibration Tests

Soil-structure interaction at CDMG and USGS accelerograph stations

1989 ◽  
Vol 79 (1) ◽  
pp. 1-14
Author(s):  
C. B. Crouse ◽  
Behnam Hushmand
Keyword(s):  
Soil Structure ◽  
Transfer Functions ◽  
Ground Motions ◽  
Free Field ◽  
Soil Structure Interaction ◽  
Imperial Valley ◽  
Structure Interaction ◽  
Fundamental Frequencies ◽  
Vibration Tests ◽  
40 Hz

Abstract Forced harmonic and impulse-response vibration tests were conducted at several California accelerograph stations operated by the California Division of Mines and Geology (CDMG) and U.S. Geological Survey (USGS) to determine the extent to which soil-structure interaction may be affecting the recorded ground motions. The results of the tests on the foundations comprising USGS Station 6 in the Imperial Valley and CDMG Cholame 1E and Fault Zone 3 stations in the Cholame Valley indicated the presence of highly damped fundamental frequencies between 20 and 40 Hz. However, at the much larger Differential Array station, a masonry-block structure approximately 6 km southwest of Station 6, a moderately damped fundamental frequency of 12 Hz was observed. Approximate transfer functions between earthquake motions recorded at the stations and the free-field motions were computed from the response data obtained from the forced harmonic vibration tests. For the three smaller stations, these functions showed peak amplification factors ranging from 1.25 to 1.4 at frequencies between 20 and 40 Hz. The amplification at smaller frequencies was insignificant. For the Differential Array station, the amplification factor was 1.5 at 12 Hz and was roughly 0.6 for frequencies between 14 and 25 Hz. These results suggest that soil-structure interaction will have little effect on ground motions recorded at the smaller stations provided that most of the energy in these motions is confined to frequencies less than approximately 20 Hz. However, at the Differential Array station, soil-structure interaction probably has had, and will continue to have, a significant influence on the motions recorded at this station.

Seismic response of sands in centrifuge tests

2008 ◽  
Vol 45 (4) ◽  
pp. 470-483 ◽  
Author(s):  
Mohammad H.T. Rayhani ◽  
M. Hesham El Naggar
Keyword(s):  
Shear Modulus ◽  
Seismic Response ◽  
Soil Structure ◽  
Site Response ◽  
Damping Ratio ◽  
Soil Structure Interaction ◽  
Response Analysis ◽  
Structure Interaction ◽  
Centrifuge Tests ◽  
Seismic Site Response

Seismic site response of sandy soils and seismic soil–structure interaction are investigated using an electrohydraulic earthquake simulator mounted on a centrifuge container at an 80g field. The results of testing uniform and layered loose to medium-dense sand models subjected to 13 simulated earthquakes on the centrifuge are presented. The variation of shear modulus and damping ratio with shear strain amplitude and confining pressure was evaluated and their effects on site response were assessed. The evaluated shear modulus and damping ratio agreed reasonably with laboratory tests and empirical relationships. Site response analysis using the measured shear wave velocity and estimated modulus reduction and damping ratio as input parameters produced good agreement with the measured site response. The effect of soil–structure interaction for structures situated on dry sand is also investigated. These tests have revealed many important insights with regard to the characteristics of seismic site response and seismic soil–structure behaviour. The tests showed that the seismic response of soil deposits, input motions, and overall behaviour of the structure are affected by soil stratification. The results showed that the seismic kinematic soil–structure interaction is not very significant for structures situated on loose sand.

Use of Simple Model to Predict the Forced Vibration Responses of Hualien Model Structure

1999 ◽  
Vol 15 (3) ◽  
pp. 117-126
Author(s):  
Cheng-Hsing Chen ◽  
Shuh-Hua Yang
Keyword(s):  
Simple Model ◽  
Dynamic Response ◽  
Forced Vibration ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Structure System ◽  
Structure Interaction ◽  
Vibration Responses ◽  
Mat Foundation ◽  
Vibration Tests

AbstractThis paper uses a simple model, the lumped single-degree-of-freedom system on rigid mat foundation, to investigate the effects of soil-structure interaction on the dynamic response of a soil-structure system. Based on that, the key parameters affecting the natural frequency of a soil-structure system can be easily identified and be used to assess the effects of soil-structure interaction. Accordingly, it was used to simulate the dynamic response of the forced vibration tests conducted at Hualien, Taiwan. Results obtained show that the simple model can predict the field responses very satisfactorily.

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