Dept. Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, USA.
School of Engineering, University of Virginia, Charlottesville, VA 22903, USA.
Waste Manag. 2020 Mar 15;105:540-549. doi: 10.1016/j.wasman.2020.02.030. Epub 2020 Mar 6.
The objective of this study was to investigate how addition of high-moisture waste (HMW) affects the hydraulic and mechanical behavior of municipal solid waste (MSW). Direct shear and hydraulic conductivity tests were conducted on MSW, HMW, and MSW-HMW mixtures prepared with HMW contents ranging from 20% to 80% (by total mass). Direct shear tests were conducted at normal stress between 22 and 168 kPa and hydraulic conductivity tests were conducted at vertical effective stresses of approximately 50, 100, and 200 kPa. A threshold HMW content of 40% was identified corresponding to substantial change in friction angle and hydraulic conductivity of the mixtures. Municipal solid waste and MSW-HMW mixtures with less than 40% HMW had friction angles between 29° and 32° and hydraulic conductivities greater than or equal to 1.3 × 10 m/s. At HMW contents above 40%, the friction angle and hydraulic conductivity decreased with increasing HMW content. At 80% HMW, the hydraulic and mechanical behavior of the MSW-HMW mixture was comparable to HMW. The HMW had a friction angle of approximately 2° and hydraulic conductivity of 1.1 × 10 m/s at a vertical effective stress of 50 kPa. Additional direct shear tests conducted on MSW and MSW-HMW mixtures soaked in water to simulate subsequent wetting post disposal revealed a decrease in friction angle from approximately 29° to 24° for MSW mixed with 40% HMW.
本研究旨在探讨高水分废物（HMW）的添加如何影响城市固体废物（MSW）的水力和力学行为。对 MSW、HMW 以及 HMW 含量为 20%至 80%（按总质量计）的 MSW-HMW 混合物进行了直剪和水力传导率试验。直剪试验在 22 至 168kPa 的正应力下进行，水力传导率试验在约 50、100 和 200kPa 的竖向有效应力下进行。确定了 40%的阈值 HMW 含量，对应于混合物摩擦角和水力传导率的显著变化。HMW 含量低于 40%的 MSW 和 MSW-HMW 混合物的摩擦角在 29°至 32°之间，水力传导率大于或等于 1.3×10-5m/s。在 HMW 含量高于 40%时，摩擦角和水力传导率随 HMW 含量的增加而降低。在 80%HMW 时，MSW-HMW 混合物的水力和力学行为与 HMW 相当。HMW 在 50kPa 的竖向有效应力下的摩擦角约为 2°，水力传导率为 1.1×10-5m/s。在水中浸泡后进行的额外直剪试验模拟了处置后的后续润湿，结果表明，混合了 40%HMW 的 MSW 的摩擦角从约 29°降低到 24°。
