《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登“垃圾成分及降解对城市固体垃圾抗剪强度的影响”

作者：Christopher A. Bareither; Craig H. Benson; and Tuncer B. Edil

刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，2012年10月，138卷第10期，1161-1174页

关键词：城市固体垃圾；抗剪强度；降解；生物反应器填埋场

摘要：该项研究的目的是评估垃圾的成分及降解对城市固体垃圾抗剪强度的影响。为准备不同降解程度的垃圾，该研究在两个地方进行垃圾取样（一个运营中的垃圾填埋场和一个垃圾转运站）并在试验室厌氧反应器中进行降解。抗剪强度的测量在直径280mm的直剪环中进行，本文对9个垃圾试样进行测量，法向应力在12~90 kPa之间变化。垃圾的抗剪强度参数-摩擦角ϕ和粘聚力c用摩尔-库伦强度准则确定，选水平位移56mm处（也就是试样直径的20%）应力为抗剪强度。通过对所有垃圾试样的抗剪强度与法向应力数据进行回归所得的复合破坏包线规律明显，得ϕ =37°，c=20 kPa。该研究进行的试验与文献中试验对比表明，对于土壤、砾石以及惰性成分所占比例较大的垃圾，所得摩擦角ϕ较大，而纸、纸板、塑料所占比例大时，所得摩擦角ϕ较低。垃圾成分对于摩擦角ϕ的这种影响只有在纤维性颗粒主要与剪切面平行时适用，剪切面为直剪中的颗粒方向。该研究中的试验还表明，摩擦角ϕ随着挥发性固体的减少，或纤维素+半纤维素到木质素（即增加降解）比例的降低而增大。本文给出了相应的对比关系，认为是垃圾的初始成分对摩擦角ϕ的降解效应产生影响。没有找到粘聚力c与垃圾成分或降解程度的关系。

Effects of Waste Composition and Decomposition on the Shear Strength of Municipal Solid Waste

Authors: Christopher A. Bareither; Craig H. Benson; and Tuncer B. Edil

Journal: Journal of Geotechnical and Geoenvironmental Engineering, Volume 138, Issue 10 (October 2012), 1161–1174

Key words: Municipal solid waste, Shear strength, Decomposition, Bioreactor landfills

Abstract: The objective of this study was to evaluate the effects of waste composition and decomposition on the shear strength of municipal solid waste. Waste was collected from two sources (an operating landfill and a transfer station) and degraded in laboratory anaerobic reactors to prepare wastes with different degrees of decomposition. Shear strength was measured in a 280-mm-diameter direct shear ring on nine wastes with normal stress ranging between 12 and 90 kPa. The Mohr-Coulomb failure criterion was used to determine shear strength parameters (ϕ = friction angle and c = cohesion intercept) of the wastes, and shear strength was selected at a horizontal displacement of 56 mm (i.e., 20% of the specimen diameter). A composite failure envelope regressed through shear strength versus normal stress data from all wastes was statistically significant, with ϕ=37° and c=20 kPa. A comparison between tests conducted in this study and in the literature indicates that larger ϕ are obtained for waste with a greater fraction of soil-like, gravel, and inert constituents, whereas lower ϕ are coincident with higher fractions of paper and cardboard or plastic. This effect of waste composition on ϕ is applicable when fibrous particles are primarily parallel with the shear plane, which is the common particle orientation in direct shear. Tests conducted in this study also indicate ϕ increases with decreasing volatile solids or the ratio of cellulose + hemicellulose to lignin (i.e., increasing decomposition). Contrasting correlations have been reported in the literature, attributed to the initial waste composition, which influences the effect of decomposition on ϕ. No correspondence was found between c and waste composition or the degree of waste decomposition.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000702