基于蚁群算法的冻结重塑黏土分数阶导数西原模型分析

掌握冻结状态下岩土体的蠕变规律,对利用冻结法施工的井筒建设安全至关重要。对人工冻结重塑黏土在-5,-10,-15 ℃下进行单轴抗压强度试验,得到温度对人工冻结重塑黏土单轴抗压强度的影响规律;根据重塑黏土冻结下的单轴强度,分别进行3个加载等级的蠕变试验,得到温度、加载等级对蠕变的影响规律。将Abel黏壶引入到西原模型,建立分数阶导数西原模型;利用蚁群算法对重塑黏土冻结状态下蠕变西原模型和分数阶西原模型进行参数辨识,通过分析2种模型的模拟结果,表明分数阶西原模型更适合于计算重塑黏土冻结状态下的蠕变规律。

Analysis of Fractional Order Derivative Nishihara Model of Frozen Remolded Clay Based on Ant Colony Algorithm

It is of great significance to master the creep law of rock-soil body under frozen state for the safe shaft construction by using freezing method. We carry out uniaxial compressive strength tests for artificial freezing remolded clay at the temperature of -5℃,-10℃ , -15℃,respectively.Furthermore, we obtain the relationship between temperature and uniaxial compressive strength of artificial freezing remolded clay. According to uniaxial strength under frozen state of remolded clay, we conduct creep test with 3 loading levels and obtain the influence of temperature and loading level on creep. Furthermore, we introduce Abel dashpot into Nishihara model and establish fractional order derivative Nishihara model. Finally, by introducing ant colony algorithm into frozen remolded clay, we finish parameter identification for Nishihara creep model and fractional order derivative Nishihara model. Through analyzing simulated results in two models, we can find that fractional order derivative Nishihara model is more appropriate than creep Nishihara model in creep calculation for frozen remolded clay.