中文摘要：

通过对湖北云应的盐岩和泥岩,以及江苏金坛盐岩的单轴、三轴蠕变试验结果的分析,研究了包括应力、围压等外在条件以及内部组成结构对盐岩蠕变特性的影响。发现盐岩无论在何种围压下,稳态蠕变率都随偏应力的增加而显著地增大;围压起到限制变形的作用,而随着围压增高,围压对稳态蠕变率的影响越来越小;晶粒越大和杂质含量越多,盐岩的蠕变属性越弱。盐岩的蠕变变形是应变硬化和回复效应等内部变形机制共同作用的结果,选用内应力作为内变量可用来描述这种内部微观结构的演化过程。对云应盐岩的多级加载蠕变试验数据进行拟合,确定了非线性蠕变本构方程中的参数,理论与试验结果的比较表明,两者吻合性较好。

英文摘要：

Through analyzing the result of uniaxial and triaxial creep tests on rock salt from Yunying and Jintan salt mine and mudstone from Jintan salt mine, the effect of external conditions concluding stress state and confining pressure and internal construction on the creep characteristics of rock salt are studied. No matter under any confining pressure, the steady state creep rate of rock salt increases obviously following the accreting detective stress. Confining pressure, which plays a role of restricting creep deformation, however, has a little effect on the steady state creep rate more and more as confining pressure increases. Furthermore, larger grain size and more inclusions in the rock salt will result in weakening creep property. In this paper, the origin and the nature of this internal stress, which develops during inelastic deformation of the material, are discussed. It is shown that this internal stress, which reflects the microstructure evolution of the material under the competitive action of hardening and recovery mechanisms and bridges the gap between micro construction and macro experimental phenomenon, can serve as an internal state variable in the creep constitutive model of rock salt. Good agreement between the numerical results obtained from the model presented and experimental data of creep curves to triaxial multi-grade compression test is given.