基于聚乙烯醇改性的隔离墙浆材渗透性能研究

Permeability of Cutoff Walls Slurry Based on Modification of Polyvinyl Alcohol

结合变水头与常水头渗透试验法测试水泥-改性膨润土隔离墙浆材的渗透系数。结果表明,聚乙烯醇对浆材渗透系数影响最大,膨润土次之,水泥最小。随着渗透压的增大,浆材的渗透系数增大;随着水泥掺量的增加,浆材的渗透系数先增大后减小;随着聚乙烯醇掺量增加,浆材渗透系数先增大后减小,且减小趋势趋于平缓,表明聚乙烯醇掺量存在一个最佳经济控制范围;随着膨润土掺量增加,浆材的渗透系数先增大后减小。综合考虑浆材的渗透性能及经济性指标,各组分掺量的最佳控制范围为:水泥210～220 g/L,聚乙烯醇2. 0～3. 0 g/L,膨润土180～190 g/L,在这一范围内,浆材的渗透系数小于1. 0×10^(-7)cm/s。

This paper took the method of constant and varying water head penetration to measure the permeability coefficient of cement-modified bentonite cutoff walls slurry.The results show that the influence of polyvinyl alcohol on permeability coefficient is maximum,the second is bentonite and the minimum is cement.The permeability coefficient of the slurry enlarged with the increase of osmotic pressure.And with the increase of cement,the permeability coefficient first enlarged and then reduced.With the increase of the polyvinyl alcohol,the permeability coefficient of the slurry first enlarged and then reduced,and the reducing trend tended to be slow,indicating that there was a best economic control range in polyvinyl alcohol.And the permeability coefficient reduced after enlarging with the increase of bentonite.Considering the permeability and economy of the slurry,the optimum control range of each component is as follows:cement 210-220 g/L,polyvinyl alcohol 2.0-3.0 g/L,bentonite 180-190 g/L.In this range,the permeability coefficient of the slurry is less than 1.0×10^-7 cm/s.