Effect Of Fly Ash On The Dynamic Characteristics Of Loess

As people’s living standards progress, the ecological environment has been destroyed,there is growing attention to environmental protection. The fly ash as a secondary product of coal-fired power plant emissions and huge increases every year, resulting in many cities nationwide severe haze phenomenon, a large number of fly ash emissions also caused enormous pressure on the national economy. With the increasingly serious situation, how to improve the comprehensive utilization of fly ash has become an issue of common concern.Therefore, accelerating the comprehensive utilization of fly ash is very necessary. In this paper TYS-20 microcomputer controlled electro-hydraulic servo soil dynamic triaxial testing machine to study the different confining pressure, under the influence of fly ash and moisture conditions of the loess dynamic characteristics were calculated and made the dynamic stress-dynamic strain curve(ds ~de curve), the dynamic elastic modulus- dynamic strain curve(dE ~de curve) and dynamic strength curve, analyzes the changing rule of dynamic strength parameter index(dynamic friction angledj and dynamic cohesionc_d), you can get the following main conclusions:(1) Fly ash loess dynamic study of elastic characteristics:A, different confining pressure, the moisture content of the soil dynamic stress- strain relationship dynamic is influential. Confining pressure, the smaller the dynamic strain with the increase in dynamic stress increases the amplitude. The higher the moisture content, the greater the dynamic strain dynamic stress increases the magnitude of the increase, and when40% of fly ash incorporated loess confining pressure of 300 kPa, the moisture content on the dynamic stress- strain curve is not moving obvious.B, different consolidation confining pressure and moisture content have a certain influence on the dynamic shear modulus and dynamic shear strain relationship of soil. The higher the confining pressure is, the larger the dynamic shear modulus of soil is, that is, the stronger the stiffness of the soil is. The lower water content, the dynamic shear modulus corresponding to the dynamic shear strain of soil is larger, that is, the stronger the stiffness of soil is. When 40% fly ash is added to the loess, the influence of water content on dynamic shear modulus and dynamic shear strain curve is not obvious. The water content is 16%, 18%,20% and 22%, the dynamic shear modulus and dynamic shear strain curves are basically in the same line.(2) Fly ash of loess dynamic strength:A, different consolidation confining pressure, different moisture content and different amount of lime content on the dynamic strength is obvious. Under the same vibration, the dynamic strength increases with the increase of confining pressure, and decreases with the increase of water content, and increases with the increase of the content of fly ash.B, dynamic strength parameters(dynamic friction angle and dynamic cohesion) are gradually decreased with the increase of the number of vibration. When the soil is pure soil and fly ash content is 20%, the dynamic friction angle and dynamic cohesive force decreases with the increase of water content. When the content of fly ash is 40%, the change law of dynamic friction angle and dynamic cohesion is not obvious. With the increase of fly ash content, the dynamic friction angle and dynamic cohesive strength increase.