Effect Of Freeze Thaw Cycles On Mechanical Properties Of Roadyes Improved Loess

Loess is widely distributed in our country,and repeated freeze-thaw cycles in seasonal frozen soil regions can cause undesirable engineering problems.Traditional curing agents such as flyash and lime have the disadvantages of polluting the environment.More new green soil solidifying agents have been developed.Roadyes as a new type of ion curing agent,soil stabilizer(hereinafter referred to as Luye)has been rapidly promoted in loess area because of its high strength,low cost and no pollution.To study the mechanical properties of Luye to improve loess under freeze-thaw cycles in cold regions,in this paper,the improved loess is tested in laboratory,and the influence of freeze-thaw cycles on the mechanical properties of improved loess was studied.Based on the confined compression test,the influence of freeze-thaw cycles on the compression characteristics of the improved loess is analyzed,and the influence rules of the number of freeze-thaw cycles and the concentration of curing agent on the compression indexes of the improved loess are explored.The function relationship between the compression deformation coefficient of the improved loess and the number of freeze-thaw cycles and vertical pressure is established.Direct shear test is used to analyze the influence of freeze-thaw cycles on the strength index of the improved loess,and the optimal mixture ratio of curing agent concentration is determined.The influence of curing agent concentration on the type of stress-strain curve of the modified loess is investigated.The effects of the number of freeze-thaw cycles and the concentration of curing agent on cohesion and internal friction Angle are studied.The evolution law of shear strength parameters under freeze-thaw cycles is analyzed.Based on triaxial shear tests,the effects of freeze-thaw cycles on the strength parameters and stress-strain characteristics of the improved loess are analyzed,and the effects of curing agent concentration and confining pressure on the strength and indicators of the improved loess are studied.Compared with the direct shear test,c and φ values are compared and analyzed.The strength damage model of modified loess under freeze-thaw cycles is established.Through the dynamic triaxial modulus damping ratio test,the influence of curing agent concentration and freeze-thaw cycles on the dynamic modulus and damping ratio of improved loess is explored.To sum up,this paper studies the variation law of mechanical properties such as compression characteristics,shear strength and dynamic modulus with the number of freeze-thaw cycles through laboratory tests,which provides theoretical reference for the application of road-liquid modified loess in practical engineering.