Study On The Static-dynamic Mechanical Properties Of Mixed Soils With Different Clayey Particles

The earthwashing intense seabed,artificial hydraulic fill sand in the coastal area,and filled soils in the alluvial zone of the river delta are generally a mixture of gravel,sand,fine soil?clay and silt?mixed according to witha certain proportion,which can be the liquefied mixed sand with some internal structure.The soil can be seen as a mixture soilincluding different content of fine particles.Under the quick development of the construction conditions,Many significant projects had built in this mixed soil area,which are facing the potential threat from heavy rainfalls and t earthquakes,such as large bridges,oil platforms,docks,coastal high-rise buildings.Little attention has taken on the static-dynamic mechanical properties of the mixed soils due to their complexity.However,it is of great significance to reveal the mechanical behaviors of the mixed soils with different content of fine particles,which can offer a theoretical basis and engineering value on the construction ofcoastal reclamation area and offshore platform.Hence,this paper will focus on the effect of the clay content on the static-dynamic mechanical properties of sand.The study is implemented by several ways as follows and some important conclusions have been obtained.1.The rapid change of cell load,the effect of the clay particle content of pore pressure changes of saturated mixed sand.This paper is used to remel the sample,the sample dry density is 1.6g/cm³,through the static triaxial tester was carried out by different clay particle content?for example Fc=0%,10%,20%,30%,40%,50%?,different cell load changes?such as??₃=10kPa,??₃=20kPa?.The experimental results show that the growth rate of pore pressure will slow down and the change of pore pressure will be suppressed.The experimental data have been fitted with the existing pore pressure model,and the results show that the pore pressure model parameters are independent of the change of load,and are closely related to clay content.Due to the existence of local structure,the existing pore pressure model can not predict the evolution of pore water pressure of high clay content.2.The effect of clay particle content on the liquefaction resistance of saturated sand.In this paper,the remanent soil with dry density of 1.6g/cm³,the saturated mixed sand with clay particle content of 0%,10%,20%,30%,40%and 50%.Under the consolidation of 100kPa,the load frequency is 1Hz and 2Hz,and the paper conducted a series of CU test.The results show that the overall trend of the clay particle content to the liquefaction resistance of saturated sand is independent of the dynamic load frequency.The liquefaction resistance and the clay particle content of the saturated sand were decreased with the increase of the clay particle content.At the lowest point of the?V?word,the liquefaction resistance of the sand was the worst,and the liquefaction was the most prone.The results show that there is a threshold of clay particle content in the liquefaction of the mixed soil with clay content.The clay particle contentt of worst anti-liquefaction capacity of the current test is about 20%.3.In the process of exploring the effect of clay particle content on the liquefaction capacity,it was found that the clay particle content had a great influence on the peak dynamic pore pressure of each vibration.The experimental results show that the effect of clay on the pore pressure of saturated mixed sand can be divided into three stages.Application of the existing pore water pressure development model to simulate the data on the test results,and the fitting parameters,extrapolating the clay content of 0%⁵0%saturation of theLi-jiang river sand peak pore pressure development model.4.In order to investigate the effect of shear rate on the CU test of each clay particle content of satutated mixed sand,the shear rate is 0.08 mm/min,0.40mm/min and 2.00 mm/min.The results show that the shear rate and clay content have a great influence on strengtht of saturated mixed sand.The results of the study show that the soil including clay has local structure,this local structure change on the development and evolution of pore pressure in sand,the static and dynamic properties,and this kind of mixed soil exists widely in geotechnical engineering practice,provide the basis and method of initial liquefaction evaluation of the conclusions of this paper can be used to study and field static and dynamic properties of this kind of mixed soil site.