三轴蠕变试验中云母石英片岩蠕变参数的研究

 通过三轴蠕变试验得到云母石英片岩蠕变参数--弹性模量与黏滞系数的变化规律，弹性模量在屈服点前后的变化规律不同，对应不同应力水平的黏滞系数–时间关系有3种类型。采用电子显微镜对云母石英片岩三轴蠕变的3个阶段--未受力阶段、即将出现加速蠕变阶段和破坏阶段的径向切片、轴向切片进行观测，获得云母石英片岩中主要矿物在三轴蠕变过程的微观结构变化。根据云母石英片岩三轴蠕变过程的微观结构变化对蠕变参数的变化规律进行合理解释。研究表明，云母石英片岩三轴蠕变过程中蠕变参数的变化规律与其微观结构变化之间有良好的对应性，蠕变参数在宏观上的变化是其内部微观结构变化的外在表现。最后，建立能真实反映蠕变参数变化规律的函数形式，并以此为基础得出蠕变模型，可作为描述岩石加速蠕变阶段的途径之一。

STUDY OF CREEP PARAMETERS OF MICA-QUARTZOSE SCHIST DURING TRIAXIAL CREEP TEST

The variation law for the creep parameters of mica-quartzose schist—elastic modulus and viscosity coefficient during triaxial creep process is obtained by the triaxial creep test. The elastic modulus has different variation laws before and after the yield stress，the relation between viscosity coefficient and time has three types at different stress level. By scanning electron microscope test，the micro-structural changes in major components in mica-quartzose schist during triaxial creep process are derived from observing the radial and axial slices of mica-quartzose schist which made from three creep stages，respectively，and the three stages are no force stage，the upcoming accelerated creep stage and creep damage stage. On this basis，a reasonable micro-scopic interpretation for variation in creep parameters during triaxial creep process is given. The study shows that variation in creep parameters during triaxial creep test for mica-quartzose schist has a good correspondence with the micro-structural changes，the macro variation in creep parameters is an external behavior of internal micro-structural changes of mica-quartzose schist. The function reflecting the actual law of creep parameters variation is established，and then the creep model is derived，which can be an approach to describe the upcoming accelerated creep stage of rocks.