土-膨润土系竖向隔离墙材料施工和易性试验研究

Experimental study on workability of soil-bentonite backfills for vertical slurry cutoff walls

为研究满足各类场地条件下土-膨润土系竖向隔离墙材料施工和易性要求的主要施工参数,对钙基膨润土浆液和钠基膨润土浆液进行马氏漏斗黏度试验、API滤失试验和密度测定,并针对砂-膨润土、黏性土-膨润土、砂-黏性土-膨润土3类土-膨润土系竖向隔离墙材料进行坍落度试验.试验结果表明,钙基膨润土浆液和钠基膨润土浆液的合理膨润土掺量分别为10%和3%.3类土-膨润土系竖向隔离墙材料的坍落度与含水率均呈良好的线性正相关性.采用标准坍落筒和迷你锥坍落筒所测定的坍落度结果之间存在统一的经验关系.采用迷你锥坍落筒代替标准坍落筒进行土-膨润土系竖向隔离墙材料施工和易性试验时,满足坍落度要求的含水率范围为其液限的1.0~1.6倍,所对应坍落度范围为22~48 mm.

In order to investigate the main construction parameters that meet the workability of soilbentonite backfills for vertical slurry cutoff walls under various types of site conditions,the marsh funnel test,API（ American Petroleum Institute） filtrate loss test and density measurement for sodium bentonite-water slurries and calcium bentonite-water slurries were carried out. The slump tests of three soil-bentonite backfills,including sandy soil-bentonite,clayey soil-bentonite sandy and soil-clayey soil-bentonite backfills,were measured. The experimental results showthat the suitable contents of bentonite for calcium bentonite-water slurries and sodium bentonite-water slurries are 10% and 3%,respectively. The slumps of three soil-bentonite backfills and the water content exhibit a good linear positive correlation. And there exists a uniform correlation between the results based on the standard slump cone and those based on the miniature slump cones. When the standard slump cone is replaced by the miniature slump cone,the water content meeting the requirements of the slump is approximately1. 0 to 1. 6 times higher than the liquid limit,and the corresponding slump is 22 to 48 mm.