动荷载作用下冻土温度变化及强度损失探讨

动荷载测温试验发现,初始温度为-6℃的冻土试样,当有循环荷载作用时,随着时间的变化即使外界恒温供冷,其中的温度仍旧会出现上升趋势,并且上升值与加载频率、动应力幅、及试样的干密度、含水率等因素有关.此外,在不同的条件下冻土强度表现出了不同程度的损失.

Temperature Change and Strength Descent of Frozen Soils under Dynamic Loading

According to a series of dynamic loading experiments with temperature records,it is found that when the initial temperature of specimen is -6 ℃,the temperature in the specimen under dynamic loading gradually increases,even if a constant cold energy is supplied.The temperature increases in logarithmic and exponential forms with increasing frequency and stress amplitude,respectively;and decreases in exponential and linear forms with increasing dry density and water content,respectively.The strength of frozen soils also shows different descent under the above-mentioned conditions.Comparison of the results from regression equations and experiment curves under the same condition reveals that the regression equations are reliable to predict the temperature change in specimen.It is important for analyzing the experimental data that there is a temperature increase due to loading.