混合型缓冲回填材料土水特征曲线测试与修正

 利用压力板法和水汽平衡法，对不同掺砂率和干密度的膨润土–砂混合物在脱湿过程中的土水特征曲线进行测试，探讨不同初始饱和条件、掺砂率与干密度对脱湿过程中混合物持水性能的影响。随着掺砂率和干密度增大，侧限饱和混合物试样持水性能下降；随着掺砂率增大，自由饱和混合物试样持水性能下降，而干密度对其持水性能基本没有影响。引入有效黏土密度和有效含水率的概念对混合物的实测土水特征曲线进行修正，发现饱和条件不同，混合物持水能力的控制因素也不同：侧限饱和条件下混合物持水性能主要受有效黏土密度控制，而自由饱和条件下混合物持水性能主要受掺砂率控制。根据试验数据拟合出侧限饱和与自由饱和后GMZ001膨润土–砂混合物修正土水特征曲线的经验公式，可用来估算高放废物处置工程中混合型缓冲回填材料的非饱和含水率。

DETERMINATION AND MODIFICATION OF SOIL-WATER CHARACTERISTIC CURVES OF BENTONITE-SAND MIXTURES AS HIGH-LEVEL WASTE BACKFILL/BUFFER MATERIAL

Both the pressure plate and vapor transfer technique are used to measure the soil-water characteristic curves(SWCCs) of bentonite-sand mixtures for understanding the effects of initial saturated condition,sand mix ratio and dry density on water-holding capacity in drying process. With respect to the bentonite-sand mixtures saturated under confined condition,it is found that the water-holding capacity decreases with the increase in sand mix ratio and dry density. While for the bentonite-sand mixtures saturat...