Abstract: The mechanical properties of frozen soil depend on not only the single factor, such as water content, temperature, strain rate, salt content, confining pressure etc., but also on the possible interaction between the mentioned factors. In order to make sure of the dependence relationship of frozen soil strength and modulus with these factors, the significant and interaction of influencing factors of frozen soil mechanical properties is studied according to the experimental data and statistics theory. The study shows that the mentioned factors have obvious influence on the mechanical properties of frozen soils; however the factor of temperature is the most important one. Furthermore, the interactions on strength, which originating between temperature, water content and strain rate, are found to be obvious enough and can’t be neglected. Therefore, it is not rational that only some separate factors are taken into account as studying the mechanical properties. The most appropriate method is to study it in overall factors and with the interaction taken into consideration.

Key words: frozen soil, mechanical property, significance test, orthogonal test, interaction