Numerical Simulation And Laboratory Research Of Liquefiable Soils Deformations During The Earthquake

The studies on dynamic behavior and liquefaction resistance of liquefiable soils have been conducted extensively in laborator. however, but it is limited by many objective factors in practice that make the distribution of the liquefiable soil layer unclear;the data of dynamic properties of the liquefiable soil layers inadequate and the influence of Seismic liquefaction to the structure unknown et al. This thesis uses the method of investigation,the testing research work in situation and laboratory,calculation analysis and summarization to systematicly research the seismic liquefaction response of the research area.Furthermore,combined with the practical project in the research area,the influence of the resistance measure of liquefaction to the structure of the practical project can be evaluated.This paper includes four parts. The first part explain the significance of study,status and contents of the study. The second part introduces the outline of the research area. Aiming at the liquefiable soil layer(saturated silts) in research area. to test research work in situation and laboratory,we can obtain site properties and the distribution character of the liquefiable soil layer. The third part analyses the dynamic properties of silts (including deformation and intensity properties) under seismic. The last one is the numerical simulation of the saturated silts liquefaction under the seismic loading by means of finite element,which can combine with the practical project in the research area,then analyzes the influence of seismic liquefaction to the structure. The detailed research process is showed as follows:Firstly, Liquefiable soil layers in research area and their basic characters are decided by investigation and regular laboratory. Moreover, In accordance with datum of test in situation,the distribution condition of the liquefiable soil layer is ascertained.The liquefiable silts dynamic character researches are conducted by means of the resonant column test and the dynamic triaxial test;The undrain dynamic relationshiop between stress and strain,the damping ratio,saturated silts liquefaction mechanism, laboratory liquefaction standard,the effective factors of liquefaction are considered in laboratory. It is found that the critical pore water pressure ratio of saturated silts in laboratory is 0.7. Liquefaction strength parameters used in element numerical simulation are obtained.Futhermore,the laboratory method prove the results of test in situation.In the finally, the effects of liquefaction resistance to Hangzhou gulf water in take and outlet tunnel section and Tianjin reservoir dam section are discussed by seismic liquefaction simulation whicah uses the liquca program.furthermore,the functions of the liquefaction resistance to seismic liquefaction response of water intake and outlet tunnel section and reservoir dam section are detailed analyzed.The innovation of this thesis is that using the test research work in situation and laboratory,element numerical simulation give the objects a detailed study which serve for the seismic resistance of project and is of great significance.