关键词: 软黏土, 温度效应, 三轴试验, 剪切特性, 应力路径

Abstract: The shear test of saturated clay with different temperatures and different heating paths was performed with the precise temperature-controlled dynamic triaxial test system. Effect of temperature on the undrained shear characteristics of saturated soft clay is explored, and the influence of different heating and consolidation methods on the pore pressure development, volume change, strength and modulus of saturated soft clay is analyzed. The results show that the undrained shear strength of saturated soft clay decreases when the ambient temperature increases from 4 ℃ to 76 ℃, but the increase in temperature has a significant effect on the increase of the soil modulus, and the relationship between them can be well fitted with the function of ET = 26.92T0.3. The excess pore water pressure of the normal consolidated clay increases with the increase of temperature, and the shear strength of the soil increases obviously after thermal consolidation, and the increase of the shear strength of the soil under the condition of drainage is less than that after the completion of thermal consolidation. When the soil mass increases from 26 ℃ by 20 and 40 ℃, the heating induced excess pore water pressure ratio is 0.41 and 0.61, and the shear peak strength increases by 8.23% and 22.37%, respectively . Studies reveal that the increase of heating amplitude will increase the degree of reconsolidation of the soil perturbation, and the more the thermal consolidation grading is, the more sufficient thermal consolidation is, and the corresponding volume change and strength growth rate are larger. At the same time, the final temperature and thermal consolidation path have an impact on the shear phase transition characteristics. The higher the temperature is, the more the thermal consolidation path is, and the more obvious the dilatancy is. However, the temperature range, consolidation classification and thermal consolidation path generally have little influence on the development of pore water pressure in general.

Key words: soft clay, temperature effect, triaxial test, shear characteristic, stress path