Study On Mechanical Properties And Compressive Creep Model Of Frozen Clay

In recent years,China has increased the development of frozen soil areas in Western China,and artificial frozen soil construction technology is widely used in coal mining and other engineering construction.Therefore,it is of great significance to start the study of frozen soil's mechanical properties.It is urgent to study the direction of frozen soil.In this paper,we choose the frozen clay under a coal mine in Shanxi Province as the research object.The mechanical properties of frozen clay are studied by using the relevant instruments of the Institute of Frozen Soil Research of Anhui University of Science and Technology.A fractional derivative Burgers creep model is established to fit the test results.The frozen direct shear tests of remolded clay were carried out at temperatures of-3?,-6? and-12? by using the frozen soil direct shear tester in the Frozen Soil Research Laboratory.The shear strength indexes of frozen clay at different temperatures were obtained.The effect of temperature on shear properties of frozen clay is analyzed.Using self-made moulds,one-dimensional lateral confined compression tests were carried out on remolded clays with freezing temperatures of-5?,-10? and-12?,with moisture content of 10%,15%and 20%respectively in the frozen soil uniaxial testing machine.The stress-strain curves of frozen clay under various conditions were plotted,and the effects of temperature and water content on its compressive properties were analyzed.A compressive creep Burgers model of frozen clay is established and simulated annealing algorithm is used to simulate the creep of frozen clay.Compared with the experimental data of compressive creep,the established model can reflect the creep characteristics of frozen soil well,but as the time goes longer enough,the fitting value will deviate seriously from the actual test value.Based on the introduction of fractional derivative,the Burgers model of fractional derivative is established.It is found that the model can reflect the actual test value in a long time,and the correlation coefficient is high.It can satisfy the needs of engineering practice and related research.It provides a new method for the study of constitutive relationship of frozen soil.Figure 31 table 5 reference 72...