Testing Research And Numerical Analysis For Earthquake Liquefaction Of Foundation Soil In The Yellow River Delta

The paper includes five parts. The first part summarizes the significance of study, status quo and contents of study. The second one shows the testing research work in situation and laboratory. The third one sets up seismic parameters and time-distance curve of ground motion through site seismic risk. The forth one analyses the dynamic properties of silts (including deformation and intensity properties) under seismic loading. The last one is the numerical simulation for liquefaction potential of the saturated silts under different seismic loading by means of finite element.According to datum, the foundation soil of the Yellow River Delta are saturated silts which are tend to liquefy. And the saturated silts have uncommon properties, which differs from other soil. At present, research work about liquefaction of this area is few. And the methods are formula coming from criterion. More research work is going to be done in order to validate these methods holding true or not. It is of pertinence and science to analyse dynamic properties of silts through test. Numerical simulation synthesizes knowledge of maths, mechanics and computer to analyses liquefaction of foundation, which is strictness and takes into account multi-factors.Seismic parameters and time-distance curves of ground motion under 63%,10% and 3% probability of exceedance are set up by analysis of site seismic risk. Research work about dynamic properties of saturated silts is studied using cyclic loading test, including shear modules, damping ratio, critical pore water pressure ratio, pore water pressure and shear strength model. At last, based on the Biot concretion theory, the paper analyses liquefaction potential of foundation under different probability of exceedance seismic loading using finite element numerical simulation. When seismicloading is 63% and 10% probability of exceedance, All sites don't liquefy. When seismic loading is 3% probability of exceedance, silts 4 meters under ground in Dongyinggang and silts 3 meters under ground in Gudong are likely to liquefy, silts between 6~8 meters in Dawangbei under ground are likely to liquefy too. And pore-water pressure surface grows rapidly.