Theoretical Study On Strength And Creep Of Artificial Frozen Soil

As one of the important properties of permafrost,the compressive strength and creep characteristics of permafrost are the main contents of permafrost engineering.Since the existence of frozen soil engineering discipline,there have been a lot of research and experiments around these two aspects.Because of the complex physical and mechanical properties of frozen soil due to its multiphase,it is difficult to use a simple mathematical model to explain the compressive strength of frozen soil and simulate the whole process of frozen soil creep.In addition,due to different geological conditions,soil category,freezing time,temperature,load and stress historical conditions and other factors on the compressive strength of frozen soil and the influence of creep property weight is different,so research on the different factors influencing the compressive strength and creep model of frozen soil under the theory study of frozen soil engineering and engineering construction is of great significance.Since the 1950s,various tests and theoretical studies have been conducted on the compressive strength and creep model of frozen soil by scholars from all over the world.The compressive strength of frozen soil is mainly determined by the characteristic stress on the stress-strain curve of frozen soil.The curve was obtained by unconfined uniaxial compressive strength test of frozen soil.The creep model theory can basically reflect the constitutive relationship between stress,strain and time of frozen soil,and the reasonable constitutive relationship should be based on the creep test of a specific material to be selected appropriately.The creep behavior of frozen soil can be described by viscoelastic mechanical model or empirical formulas.Nowadays,many scholars use fractional derivative creep model to study the creep characteristics of frozen soil.Fractional derivative is actually Abel type on the integral of the kernel function,it can establish a fractional derivative model of factors such as temperature,can be accurately fitting the creep process of frozen soil,and simple,unified form,in the process of calculation need to adjust the parameters of the very few,often better than the classical Maxwell model,classic Kelvin model,classic Burgers was not the three components of solid model,the classical model,the classic AD model is more precise.As for the compressive strength of frozen soil,this paper mainly studies the influence of the four aspects of soil type,temperature,moisture content and salinity on the prediction of the compressive strength of frozen soil,and establishes the prediction model of the compressive strength of frozen soil.For the creep model of frozen soil,the classic Kelvin model,classic three components of solid model can describe the creep process of frozen soil,but for the long-term creep process simulation result is bad,and no considering the type of soil,the influence of temperature,moisture content and salinity,etc,so this article on the basis of the classical Kelvin model introduced some related parameters and analysis of the fractional order derivative,established a new creep model considering the above factors of fractional order derivative,through the optimization of particle swarm optimization(pso),makes the model more in line with the physical properties of frozen soil and engineering practice.Figure[58]table[26]reference[80]...