垃圾填埋场防渗浆材及其阻滞规律的实验研究

针对垃圾填埋场防渗要求高的特点,在渗滤阻滞作用和吸附阻滞作用阻滞机理研究的基础上,选用粉质黏土、钠基膨润土、水泥和粉煤灰材料进行了SBCF浆材研究,通过大量正交实验研究和重复试验优选出SBCF浆材配方,其56d结石体的渗透系数1.48×10-8~1.71×10-8 cm/s,抗压强度为1.10~1.12MPa,弹性模量为97.7~99.7MPa。采用自有专利研制的柔壁渗透仪进行了浆材结石体对垃圾渗沥液中污染物阻滞规律的实验研究,实验表明阻滞率均随试样高度增加而增大,且在开始渗滤的100mm内阻滞率增加较快,大于100mm后阻滞率增加减缓,当试样高度达到180mm时,对垃圾渗沥液中主要污染物的阻滞率均能达到95%以上,并可将此实验规律作为设计防渗墙墙体厚度的依据。该浆材具有渗透系数低、对污染物阻滞率高、塑性与耐久性好、无化学添加剂、无污染、原材料来源广和经济性好等特点,可用于新建或既有垃圾填埋场、建筑基坑工程和水利工程防渗处理。

Experimental research on antiseepage slurry used in waste landfill sites and the retardarce law

Aiming at the high seepage control requirement of waste landfill site, and based on the research of the retardarce mechanism of the absorption retardarce action and the percolation retardarce action,the silty clay,sodium bentonite,cement and fly-ash material are selected to begin SBCF slurry research. Through a large amount of orthogonal experiments and repeated tests,optimized formulations of the SBCF was obtained, and the permeability coefficient of slurry stone in 56d is 1.48 × 10^-8～1.71 × 10^-8 cm/s, the compressive strengthis 1.10 ～1.12 MPa, and the elastic modulus is 97.7～99.7 MPa. The experimental research on retardance law of slurry stone to pollutants in waste leachate is done by using the flexible wall permeameter which is self-developed own patent. The experimental results show that all the retardarce rates will increase with sample highing,and in the beginning of 100 mm,the retardance rate increase rapidly. After more than 100 mm,the retardarce rate increase will slow. When the sample height is up to 180 mm,the retardance law of the slurry stone to main pollutant in waste leachate can reach more than 95%. This retardance law gained from the experiment can be used as the basis for the design of cutoff wall thickness. The SBCF slurry possesses some good characteristics as the low permeability coefficient,the high retardarce rate to pollutant, the good plasticity and durability, no chemical addition, no pollution, the wide source of materials,and good in economy,and so on. The slurry can be used for antiseepage in new or existing waste landfill sites,building foundation pit engineering,and water conservancy engineering.