The Research On The Liquefaction Of Silt

The research of soil liquefaction characteristics is an important content of the earthquake engineering and geotechnical engineering, the early research of the soil liquefaction focused on discussing the residual strength of the resistance and the evaluation of the pure sand when it happened to liquefy, the study for saturated powder sand in vibration dynamic characteristics under the vibration force was still not sufficient, the research results were relatively few. In order to master the liquefaction of the pure sand, considering the climate and geology environment in nen river valley, the paper took soil from subgrade of QiTai highway as sample and maked triaxial test, made research of the sand liquefaction.Mealy sand was natural grain soil between sand and powder soil. The mealy sand contents little clay particle, its saturated ability is small, while its water-retaining property is poor. The mealy sand will liquefy under the saturated conditions, while the dynamic stress reaches a certain level. The paper studied the vibratory liquefaction strength of the mealy sand. Based on the dynamic triaxial test results, the paper discussed the influence of dry density and fine-grained content to liquefaction strength of mealy sand. The results of the study indicated that: dry density and fine grain content were factors that affected the vibration liquefaction, the bigger dry density, the larger liquefaction strength. According to the results of the dynamic triaxial test, the liquefaction strength of the mealy sand was not increasing with the increase of the content of fine grained, it would be its lowest point, when the fine particle content to certain amount. For this trial, when the powder soil sample fine particle content reached about 40%, the liquefaction strength to be the lowest. According to the test results, the paper researched the increasing law of pore water pressure and permanent strain potential for the mealy sand under the liquefaction condition, analyzed and fit the test result, made analysis of the low of the pore pressure growth and deformation growth for the mealysand in the condition of motive power with the classical mathematical model, made qualitative explaining of the sand liquefaction in theory.