The Study On Liquefaction Test And Numerical Analysis Of Saturated Silty Soil In The Yellow River Flood Area

The Yellow River flood area in Shandong Province whose surface is deposited by flood sediments which is about ten meters thick is formed mainly alluvial deposits of Yellow River. The flood sediments is mainly constituted of silt and fine sand, forming special geological conditions in this area. The regional foundation which is loose and low intensity is bad in construction.The highways are widely applied in the Yellow River flood area,but some of their sueface crake and fail to work because of the liquefaction and differential settlement induced by variation of groundwater level and impaction of vehicle'vibration.In case of earthquake, liquefaction will become more prominent.Therefore,it seriously influences application and increases maintaining expenses.The liquefaction of silt is a serious problem to be solve.In this paper,the liquefaction of saturated silt ground was studyed systemly and deeply.The dynamic characteristics of saturated silt in the Yellow River flood area was also studyed. The laboratory test, field test,and the numerical analysis methods were used in the article. The primary studies listed bellow were carried out:(1)The engineering geological characteristics of saturated silty soil was introduced.The special physical and mechanical properties of silt in the Yellow River flood area was analyzed which is the basis to study the liquefaction by the moisture test,particle size distribution test,limit water test and compaction test we had done in the Laboratory.(2)This paper introduced the dynamic characteristics of saturated silt in the Yellow River flood area were studyed by triaxial test. From the results we knew that the density and the amount of clay content were important factors that affected the dynamic strength of saturated silty soil in this area.(3)The saturated silt ground in this area which was exerted by seismic loads was simulated numerically by using FLAC-3D. Liquefaction in surface of powder foundation occurred less likely and with the increasing depth of foundation it occurred more likely. The density of soil in upper layer increased because of the role of dynamic compaction. And as density increased, the dynamic strength of soil in this region improved,thus improving the soil liquefaction resistance.It provides a theoretical basis for the popularity of dynamic compaction in the Yellow River flood areas.The paper has some guidance significance for the liquefaction of foundation under the effect of vehicle dynamic load in in the Yellow River flood areas and scientific forecast of transmutation, possesses engineering practice importance for road foundation treatment, and is provided with promotion effect for the study of foundation soil changes under the effect of vehicle dynamic load.