破碎岩石具有显著的蠕变特性,可引起孔隙连续变化,从而导致渗透特性的连续变化。利用自制的破碎岩体多相耦合蠕变试验装置,研究饱和破碎泥岩蠕变过程中孔隙的变化规律。结果表明,破碎泥岩蠕变过程中孔隙率与时间呈负指数关系,整个过程具有明显的阶段性;荷载相同时,破碎泥岩粒径越小,孔隙率变化也越小,最终稳定下来的孔隙率越大;随着荷载的增大,这种因粒径不同而产生的孔隙率大小差异逐渐缩小;相同粒径下,荷载越大,孔隙率变化越快。
Broken rock shows obvious creep properties. Creep causes the continuous variation ofporisity as well as the seepage characteristics. The variation law of saturated broken mudstone porosity during creep process is studied by using the self-developed multiphase coupling creep test device. The results show that during the creep process of the broken mudstone, the porosity has a negative exponential relation with time, and the complete process can be divided into several obvious stages; when the load is the same, the smaller the mudstone particle size is, the smaller the variation of the mudstone porosity is, and the larger the final porosity is. As the load increases, the difference of the porosity caused by the different mudstone particle sizes becomes smaller; under the condition of the same mudstone particle size, the porosity of the mudstone has a quicker variation under bigger loads.