School of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212003, China.
Environ Sci Pollut Res Int. 2021 Aug;28(30):40053-40059. doi: 10.1007/s11356-020-08420-0. Epub 2020 Mar 20.
Extensive attention has been paid to the treatment and disposal of dredged material, and there is a need to clarify the feasibility of recycling dredged material by using it as backfill in soil-bentonite vertical cutoff walls. By setting the dredged material in the Baimao storage yard of Meiliang Bay in Taihu Lake and bentonite as the research objects, this paper studied the influences of bentonite content, confining pressure and pore size distribution on the permeability of dredged material-bentonite backfills. According to the test results, from the perspective of medium-term and short-term permeability, it is feasible to recycle dredged material by using it as backfill in a vertical cutoff wall. The permeability of the dredged material-bentonite soil mixture decreases with increasing bentonite content, but the degree of decrease is not significant. At the same time, the higher the confining pressure is, the smaller the variation in hydraulic conductivity with bentonite content. The permeability of the soil mixture decreases with increasing confining pressure, and the range of reduction is within a certain order of magnitude. Moreover, the confining pressure has a similar impact on the decrease in the permeability of the soil mixtures with different bentonite contents. The hydraulic conductivity of the dredged material-bentonite mixture decreases because the addition of bentonite changes the pore size distribution and reduces the porosity and characteristic pore size D of the soil mixture.
人们已经对疏浚材料的处理和处置给予了广泛关注，需要明确利用疏浚材料作为土-膨润土垂直防渗墙回填材料的可行性。本文以太湖梅梁湾白茅沙堆场的疏浚材料和膨润土为研究对象，研究了膨润土含量、围压和孔径分布对疏浚材料-膨润土回填材料渗透性的影响。根据试验结果，从中短期渗透性的角度来看，利用疏浚材料作为垂直防渗墙的回填材料是可行的。随着膨润土含量的增加，疏浚材料-膨润土土混合物的渗透性降低，但降低的程度并不显著。同时，围压越高，膨润土含量对水力传导率的变化越小。随着围压的增加，土混合物的渗透性降低，降低幅度在一定数量级范围内。此外，围压对不同膨润土含量的土混合物渗透性降低的影响相似。由于膨润土的添加改变了土混合物的孔径分布，降低了土混合物的孔隙率和特征孔径 D，从而导致疏浚材料-膨润土混合物的水力传导率降低。
