【摘要】 在土木、水利及核废料处置工程中,应力状态对岩石渗透性的影响已逐渐成为一个无法回避的问题。通过瞬态压力脉冲法,测试泥质粉砂岩和褐红色泥岩等2种典型软岩全应力-应变过程中的渗透系数。试验结果表明:(1)泥质粉砂岩的渗透系数在弹性阶段随轴向应变发展逐渐减小,在随后的塑性及破坏阶段逐渐增大;垂直于层理方向上的渗透系数大于平行于层理方向上的渗透系数。(2)褐红色泥岩的渗透系数在塑性阶段随轴向应变发展逐渐减小,而在蠕变阶段基本不变;垂直于层理方向上的渗透系数和平行于层理方向上的渗透系数无明显差异。结合试验中同时得到的应力-应变曲线,认为在弹性变形阶段,泥质粉砂岩的渗透系数主要受孔隙和微裂隙控制,而在塑性变形阶段和峰后变形阶段,渗透系数主要受裂隙影响。褐红色泥岩的渗透系数在整个应变过程中同时受孔隙和微裂隙的影响,两者的作用没有明显差别。更多还原

【Abstract】 In civil engineering,hydraulic engineering and nuclear wastes disposal engineering,great attention is focused on the influence of stress state on rock permeability.The permeability coefficients of clayey siltstone and brown mudstone were investigated by the transient pulse technique in the complete stress-strain curve.The results show that:(1)The permeability coefficient of clayey siltstone decreases in the stage of elastic deformation but increases in the stage of plastic deformation and the fractured phases.The permeability coefficient on the direction vertical to the bedding plane is larger than that on the direction parallel to the bedding plane.(2)The permeability of brown mudstone decreases in the stage of plastic deformation but keeps stable in the stage of creep deformation.The permeability coefficient on the direction vertical to the bedding plane is similar to that on the direction parallel to the bedding plane.Combined with the stress-train curves,it can be deduced that in the stage of elastic deformation,the permeability coefficient of clay siltstone is mainly influenced by porosity and small cracks;and in the stage of plastic deformation and the fractured phases,it is mainly influenced by small crack.In the complete deformation process,the permeability coefficient of brown mudstone is influenced by porosity and small cracks,boty effects are not distinguishable.更多还原