利用改进的常规三轴仪压力室作为柔性壁式渗透仪,进行了渗透系数最低有效围压的试验研究.结果显示,低有效围压情况下,试样侧壁必须涂凡士林才能保证试验精度;柔性壁式渗透仪试验的最低有效围压大致为3 kPa.为了研究水泥土渗透系数随压力的变化规律,利用该渗透仪对取自长江某段干堤应急加固工程的防渗墙水泥土进行有压条件下的渗透试验,试验结果表明:当围压较低时,水泥土渗透系数较大,随着围压的增大,渗透系数迅速减小.渗透系数随围压的变化关系可以用幂函数表示.
Experimental study on permeability coefficient and minimum effective confining pressure has been done by using improved triaxial apparatus as a flexible wall permeameter.The research results show that it is necessary to smear vaseline to enhance the examination precision of the test in the condition of the lower effective confining pressure.At that time,the minimum effective confining pressure of the flexible wall permeameter test is about 3 kPa.In order to study the relationships between permeability coefficients and confining pressures,the permeability coefficients under various confining pressures are measured in the seepage tests of cutoff wall soil-cement of the Changjiang dike emergency reinforcement project,of which the results indicate that when the confining pressures are lower,the permeability coefficients are higher;however,the permeability coefficients decrease rapidly as the confining pressures increase.The relationships between permeability coefficients and confining pressures can be represented by a power function.