Mechanics Experiments Research Of Lighweight Soil Mixed By Foam And Fibers

Lightweight foam mixed soil is a kind of light weight material,which is made of light material EPS(Expanded Polystyrene)foam particles,curing agent and raw soil.Compared with the common soil,the material has the advantages of small density,good standing,durability,economy,environmental protection and so on.It has wide application prospect.In order to improve the properties of light soil,the fiber is added to form the light mixed soil(hereinafter referred to as light soil).With the help of unconfined compressive strength test and direct shear test,the deformation and strength characteristics of lightweight soil were studied.Specific research contents are as follows:(1)The density characteristics of light soil were obtained by density experiment.EPS particle mixing ratio and EPS particle size is the main factor affecting the density,EPS particle mixing ratio and particle size increases,as the light soil density decreases,and the cement content and fiber length density of lightweight soil is not obvious.(2)The deformation characteristics of different distribution of light soil.In this paper,the stress strain pattern and shear stress pattern of shear stress of light soil were analyzed by means of unconfined compressive strength test and direct shear test.On unconfined compressive strength of stress strain curve fitting,confining is studied the changing laws of compressive modulus of deformation,deformation modulus and compressive strength of the relationship.(3)In the absence of lateral compressive strength,the compressive strength decreases with the increase of the number of EPS particles and the size of the particle size;With the increase of cement mixing,no lateral pressure strength increases;As the fiber length increases,the unconfined compressive strength presents the increasing trend,and the integrity of the light soil is enhanced.(4)In the direct shear test,the shear strength decreased and the cohesion decreased with the increase of EPS and particle size.With the increase of cement,the shear strength of light soil is increased,and the cohesion is increased.The fiber length from 9mm to 12 mm,the shear strength increase of 40%,show that the fiber length reaches 12 mm to be able to significantly improve the shear strength of light soil.(5)Light soil unconfined compression failure pattern: EPS particle size of 0.5 ~ 1mm light soil formation about 45°cracks and brittle failure,EPS particle size for 2 ~3 mm light soil formation is more than 45°cracks,EPS particle size is 3 ~ 5 mm light soil appeared to bulge.Direct shear fracture: the shearing surface of the sample damage is obvious,the shearing surface of the EPS particle size is more flat,and the shear surface of the granulated size is relatively loose.The addition of the fibers,the sample splitting and the total improvement of the soil.