The Research On Soil-structure Interaction Based On Floor Vibration Test

For a long time, the rigid ground assumption has been used for earthquakeresponse analysis in the seismic design in which only superstructure is considered inthe mode. But, a vast amount of theoretical and test research demonstrates thatsoil-structure dynamic interaction has a great influence on the dynamic characteristicsof superstructures. Soil-structure interaction(SSI) is an important subject with greattheoretical significance and application value of engineering. Though the significantprogresses on the respects of theory and application for past forty years have beenmade，there are still important problems to be solved. The paper is centered on a floorvibration test under low-frequency exciter done on a steel frame-raft foundationmodel in the Soil-Structure Laboratory， College of Civil Engineering， HunanUniversity. The author anticipated to obtain an improved insight in the soil-structureinteraction problem on the basis of organized theoretical analyses and experimentalsurvey? so we can provide the guidance for engineering application. The article isdivided into five chapters, as follow:(1)Through the summarization and review of numerous related literature，thearticle recalls the dynamic soil-structure interaction research on the theory of thedevelopment of history and various research methods, discusses the engineeringsignificance of the study on SSI, and in particular, the results of this research in thefield of seismic design code in domestic applications.(2)The floor vibration test under low-frequency exciter of steel frame model isintroduced？ including the testing of site soil dynamic parameters, the production ofthe structure model, the design of test conditions, as well as specific test operation.(3)Through the derivation about soil-structure interaction system based onequivalent single-degree-of-freedom，we got the solution of equivalent stiffness of theSSI system and the upper structure.(4)Floor vibration test under low-frequency exciter were conducted on the steelframe structure covering9different scenarios with varied stiffness and mass of thesuperstructure？ and with different base fixities. We analysis the test data in the timedomain and frequency domain in order to study the change of structural fundamentalfrequency,displacement and internal force. At the same time,we explored therelationship between the ratio of mass to weight of upper structure in per unit area and SSI effect. And，some beneficial conclusions were made.