为揭示复杂地质条件下粉砂质泥岩的蠕变力学特性,利用多相耦合蠕变试验装置及声发射监测系统,对取自某矿井2种粒径粉砂质泥岩进行了饱水状态下不同温度和围压的蠕变力学试验。研究结果表明:粉砂质泥岩的内部结构特征及所处的外部复杂地质条件会对其长期力学行为产生显著影响;围压越小、温度越高、粒径越大的粉砂质泥岩强度越低而稳态蠕变率越大;稳态蠕变速率随围压的升高呈线性降低,随温度的升高呈指数函数增长;蠕变过程中泥岩的孔隙率变化趋势与蠕变速率相似,均呈“U”型分布,相同围压和温度下,粒径越大的试件,孔隙率变化幅度越大;温度越高,围压越大,蠕变声发射信号越是呈“高频率、高幅值”,粒径越大,声发射信号越显著。研究成果可为进一步揭示粉砂质泥岩在复杂地质条件下的流变特性提供理论和试验支撑。

In the aim of revealing the creep properties of silty mudstone under complicated geological conditions, creep test was carried out on water-saturated silty mudstone of two different particle sizes collected from a mine under varying temperature and pressure condition by using multiphase coupling creep test device and acoustic emission monitoring system. Results suggest that the internal structure and the external geological environment both exert remarkable influence on the long-term mechanical behavior of silty mudstone. With the decline of confining pressure, rising of temperature, and increase of grain size, the strength of silty mudstone reduced while steady creep rate increased. Steady creep rate decreased linearly with the increase of confining pressure, but augmented exponentially with the rising of temperature. Porosity changed in a similar trend with creep rate, both displaying a U-shape distribution. Under the same confining pressure and temperature, the larger the grain size of specimens, the greater the porosity changed. Moreover, with the rising of temperature and confining pressure, the acoustic emission signal displayed higher frequency and larger amplitude; signals in specimens of larger grain size were more evident.