| Nowadays,coastal cities are expanding to the sea.In most reclamation projects,the soft soil foundation’s moisture is high and the bearing capacity is poor.During the research,we find that the steel slag has a hard texture,strong water absorption capacity.Considering to incorporate it into the sludge to reduce the water content of the soil and improve the bearing capacity of the foundation effectively.However,the quality of the steel slag is heavier,and it may cause sedimentation of the soil.So we consider to inclusive the tire particles into soil to reduce the weight of the soil and lighten the possibility of settlement.In order to study the strength characteristics of the soil conweniently,Firstly,we will study the static strength of the sludge modified by steel slag and tire particles.Secondly,Study the dynamic strength of the improved soil.We will introduce the relavent research content following the four below aspects.(1)Firstly.the shear strength characteristics of steel slag modified silt are studied by automatic triaxial instrument.The relationship between steel slag content and soil density is obtained.The effects of confining pressure,steel slag content and water content on soil stress-strain curve characteristics and failure stress are analyzed.The shear strength of soil with different steel slag content is obtained.Comparing with traditional soils.It is concluded that the incorporation of steel slag can effectively improve the shear strength of the soil,When the moisture content of the sludge is 50%,and the the steel slag content is 70%.The soil has a higher shear strength.(2)Secondly.the shear strength characteristics of modified silt soil with steel slag and tire particles are studied by static triaxial test.The influence of tire particle incorporation on soil density is analyzed.And the influence of confining pressure,steel slag content tire particles content and water content on soil stress-strain characteristics and destructive stress;the shear strength index of soil under different tire granules is obtained.Comparing with traditional soil,the shear strength improvement of soil is analyzed.It is found that the incorporation of tire particles can effectively reduce the density of the soil and increase the internal friction angle of the soil.The Duncan-Chang model has a good fitting result.(3)Then.the dynamic strength characteristics of steel slag modified silt are studied by dynamic triaxial instrument.The relationship between dynamic elastic modulus and damping ratio of soil and steel slag content is analyzed,and the maximum dynamic elastic modulus and damping ratio of soil under different working conditions are obtained.The relationship between the maximum dynamic modulus and damping ratio of soil and steel slag content,confining pressure and sludge moisture content is studied.Finally,the maximum dynamic modulus of the soil under different working conditions is compared with various composite soils to analyze the strength and inferiority of the dynamic strength characteristics of the packing.It is found that the incorporation of steel slag can significantly increase the dynamic elastic modulus of the sludge.When the sludge moisture content is 50% and the steel slag content is 70%,the dynamic elastic modulus of the soil is significantly higher than that of the traditional composite soil.(4)Finally,the tire particles are mixed into the sludge to study the dynamic strength characteristics of the tire granular steel slag improved silt soil.The dynamic elastic modulus damping ratio of the soil and the relationship between the maximum dynamic elastic modulus and damping ratio,the tire particle content,particle size,steel slag content,confining pressure,and sludge moisture content is analised.The Hardin model is used to fit the dynamic constitutive relationship of the improved soil.And compared with the maximum dynamic modulus of the composite soil.It is concluded that the incorporation of tire particles can effectively increase the damping ratio of the soil.In the 50% moisture content sludge,when the steel slag content is 70%,the tire particle content is 10%,and the particle size is 3-4 mm,the dynamic elastic modulus of the soil is the largest,and equal to the subgrade fill with compaction≥90%. |
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