三轴应力条件下凝灰岩广义应力松弛流变模型的构建

Establishment of generalized rheological model for rock under triaxial stress

岩石的长期稳定性是影响岩土工程设计和施工的重要因素。在由弹性元件和Abel黏壶元件串联组合得到Abel黏壶蠕变模型的基础上,进一步提出适用于描述流变各个方向应变随时间演化的流变模型——广义Abel黏壶模型。根据不同围压条件下凝灰岩广义应力松弛特性试验结果,对凝灰岩流变特性进行分析计算,并将适用于蠕变方向的广义Abel黏壶模型与Kelvin蠕变模型进行对比。结果表明:构建的广义Abel黏壶模型能很好地描述凝灰岩广义应力松弛流变减速阶段和稳定阶段中的应变变化规律,对凝灰岩广义应力松弛特性的分析具有更好的拟合优度。

The stability of rock is an important factor affecting the design and construction of geotechni-cal engineering.Based on the Abel clay pot creep model obtained by Hookean solid and Abel clay pot in series,the generalized Abel clay pot rheological model is proposed,which is suitable for describing the evolution of strain in all rheological directions with time.According to the test results of tuff generalized rheology characteristics under different confining pressures,the rheological properties of tuff are analyzed and calculated,and the applicability of the generalized Abel clay pot rheological model of the creep direction is compared with the Kelvin creep model.The results show that the generalized Abel clay pot rheological model established in this study can describe the law of strain change in generalized rheo-logical deceleration stage and stable stage of tuff well,and has better goodness of fit for the analysis of tuff generalized rheology characteristics.