时温叠加法确定土工合成材料蠕变折减系数

Determination of creep reduction factor of geosynthetics by time-temperature superposition

简单地介绍了加速土工合成材料蠕变试验的时温叠加方法原理和,移动因子的计算公式和意义。如果试验所得的曲线有拐点,则相邻曲线既有水平移动也有垂直移动。利用时温叠加方法得到的移动后的应力-时间曲线,可以直接确定土工合成材料设计寿命时的蠕变强度,抗拉强度除以蠕变强度即为蠕变折减系数。还重点阐述了利用时温叠加法确定蠕变强度和蠕变折减系数的步骤和过程,同时给出了具体的算例,并提出了建议和有待改进之处。

The principle of time-temperature superposition (TTS) which can accelerate creep test of geosynthetics is introduced. The calculated formula and method of time shift factors are also introduced. If an inflexion point is present in curves, adjacent curves are shifted both horizontally and vertically. The creep strength of geosynthetics at the designed life by TTS can be determined by the curves of stress vs time. The creep reduction factor is determined with dividing the ultimate tensile strength by long-term creep strength. The procedures of determination of creep strength and creep reduction factor by TTS are mainly discussed in this paper. Finally, an example and some suggestions about improvement of this method are given.