【摘要】 通过提高岩石蠕变实验时的数据采集密度来捕捉岩石破裂的微观信息,进行了泥岩三轴蠕变实验微观破裂时间点的界定与分析。研究得到了泥岩三轴蠕变过程4分区特征:Ⅰ区斜率较大,蠕应变振动幅度较低;Ⅱ区斜率中等,蠕应变振动幅度较高;Ⅲ区斜率近乎为0,蠕应变振动幅度高;Ⅳ区的斜率由较大迅速增加至最大,蠕应变振动幅度渐进缩小至最低。发现各亚阶段蠕变率平均值与蠕变时间之间呈"降低—稳定—0—渐进增长—急速上升"规律。得到了泥岩三轴蠕变过程的区段间特征:一定的应变速率有利于岩石应变演化的相对平衡;应变速率为0的亚阶段轴向应变振幅渐进放大,岩石破裂是能量单调积累的结果;蠕变初期和加速蠕变末期的岩石变形模式比较简单。通过蠕变曲线4分区与传统蠕变3阶段的微破裂特征辨析,得到微观尺度下岩石加速蠕变阶段的多样性和稳态蠕变阶段的复杂性特点。更多还原

【Abstract】 By increasing points of data collection in rock creep test,information of microcosmic cracks were caught to determine their time positions in triaxial creep testing curves of mudstone.Triaxial creep process of mudstone was divided into four stages and many sub-phases,which slope is higher and creep fluctuation range is lower at the first stage,slope is middle and creep fluctuation range is higher at the second stage,slope is approximately zero and creep fluctuation range is higher at the third stage,higher slope increase to be the maximum one and creep fluctuation range decrease to be the lowest one gradually at the fourth stage.Average creep strain rates of every sub-phases are depressed,stable,zero,gradual growth and zoomac with creep time.Creep properties of mudstone among different developing stages or sub-phases present that definite creep strain rates are propitious to relative equilibrium of rock creep strain’s evolution.Fluctuation range of axial creep strain can be enlarged gradually in sub-phase whose strain rate is zero,which states that rock cracks are coupled with monotonous accumulation of energy.Deformation modes are relatively simplified in initial creep stage and telophase of accelerated creep stage.Comparing microcosmic cracks’ features from four-subarea creep curves with that from traditional three-phase creep curves,accelerate creep phases of rock masses should be multiform and their steady creep phases must be complicated in microcosmic scale.更多还原