Study On The Strength, Frost-Sweal And Fractal Character Of The Aeolian Soil In The West Of Liaoning Province

The physical property of aeolian soil is studied systematically by testing moisture content, density, specific weight etc., grain analysis and fractal character. The physical parameters show that the thin grain is main grain in the grain of aeolian soil, and its construction is opposite and fine. Aeolian soil does not have the obviously wet sinking after soaking in water, so it has the property of frosting heave. At the same time, its grain distribution has obviously self-similarity.The single-axle strength experiments with different frosting temperature and moisture content are tested, which obtains the breakage form of aeolian soil as: it presents plastic breakage under the condition of high temperature and low moisture content, otherwise, it presents brittle breakage. Based on the theory of fractal interprolation, the - curve of aeolian soil is obtained. By testing the tri-axle strength and creep experiments with different frosting temperature and round press, the tri-axle constitutive function and creep function are obtained using regression method on the basis of theory analysis.The dynamic damage test system(DDTS) is designed by making use of SYC-2 nonmetal supersonic test meter. The relations between compressive strength, tensile strength, elastic modulus, etc. and wave parameter in frozen aeolian soil is studied using DOTS. The TTDS realizes dynamic test of damage in frozen aeolian soil, based on damage and fractal theory, the experience function of damage variable and fractal dimension with stress are obtained.The moisture migration of frosting aeolian soil is tested under the condition of different frosting temperature, moisture content and dry density. A mathematic coupling model of moisture and heat in the process of moisture migration is established, and the rule of temperature distribution is obtained. The change degree of moisture content is in direct proportion to time and temperature, and it is in inverse to dry density. The results of SEM in the process of moisture migration show that the moisture migration aggravate the phenomenon of uneven distribution and reunion in soil grain, at the same time, the phenomenon of uneven distribution and reunion in soil grain also help to form passageway of moisture migration, which is beneficial to moisture migration. Therefore, the rearrange of soil grain and moisture migration act each other.The system of frosting-sweal experiment acted on moisture, temperature and load is made by oneself, and the frosting-sweal experiments of closed and unclosed system are done. In closed system, the stress don't affect obviously the change tendency of frosting heave in the frosting and sweal process, mainly the final frosting heave. In the unclosed system, the outside water makes the frosting heave increase, and the periodicity and scope of frosting heave is more obvious. If the specimen is loaded, the change of sweal is considerably steady. Because of promotion action of load to sweal and rearrange of soil grain, the beginning sweal velocity is quicker than that of unload, but the final sweal value is little.By testing the moisture migration of aeolian soil, in a certain depth near cold end, the moisture content of frozen soil not only increase, but decrease. Therefore, this phenomenon is defined as "End Effect" in the paper, and it is unable to be considered in the numerical calculation.The result of frosting-sweal experiment show that low temperature leads to increase of frosting heave, meanwhile, the increase of temperature gradient is harmful to adequacy of moisture migration. According to the above, both temperature and temperature gradient should beconsidered for researching the influence and estimation of temperature to frosting heave and numerical model. The above phenomenon is defined as "Temperature Effect" in the paper.From theory and experiment analysis, the research make known that the frost heave curve has well self-similarity, namely the curve of frosting heave has fractal character. Based on fractal theory, this paper proposes fractal optimi...