填埋场内垃圾的持水特性和孔径分布研究

张文杰; 陈 鲁; 严宏罡

doi:10.11779/CJGE201808015

填埋场内垃圾的持水特性和孔径分布研究 English Version

上海大学土木工程系, 上海200072

基金项目: 国家自然科学基金项目（51478256,41772300）

详细信息

作者简介:
张文杰(1978- ),男,博士,副教授,主要从事环境土工方面的研究工作。E-mail: zhwjlyl@163.com。

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出版历程
- 收稿日期: 2017-07-20
- 发布日期: 2018-08-24

Water retention characteristics and pore size distribution of landfilled municipal solid waste

Department of Civil Engineering, Shanghai University, Shanghai 200072, China

摘要

摘要: 土-水特征曲线（SWCC）描述了含水率和基质吸力的关系,并在一定程度上反映了孔隙组成,然而生活垃圾具有大孔隙特性,采用常规的压力板仪试验难以准确获得大孔隙对应的低基质吸力范围内的数据点。通过压力板仪试验确定小孔隙对应的数据点,通过水分穿透试验,基于Poiseuille定律和Young-Laplace方程,对大孔隙对应的数据点进行补充,之后,基于Van Genuchten方程,提出具有双峰孔隙分布特征垃圾的SWCC模型,进一步分析得到垃圾的孔径分布规律。结果表明,改进的SWCC方程可更好反映垃圾持水特性及孔径特征; 垃圾饱和含水率和残余含水率较高,浅层、中层、深层垃圾的田间持水率分别为38.5%,42.2%和45.8%,对应的基质吸力约为3~8 kPa,随着埋深和龄期的增加,垃圾的有效含水率区间和给水度减小; 以基质吸力1 kPa对应的孔径为界限,垃圾中孔隙可分为大小两组,孔径概率密度呈双峰分布,随着埋深和龄期的增加,垃圾的大孔隙占比减小,大孔隙平均孔径减小,小孔隙占比增加,小孔隙平均孔径减小。
- 城市生活垃圾 /
- 大孔隙 /
- 双重孔隙度 /
- 土-水特征曲线
Abstract: The soil-water characteristic curve (SWCC) is usually used to describe the relation between water content and matric suction, and to some extent the pore distribution. However, the data at low matric suction are difficult to achieve by using the pressure plate extractor because of the macropore characteristic of municipal solid waste. The SWCCs corresponding to small pores are measured by the pressure plate extractor, and those corresponding to large pores are determined by means of the water breakthrough curves, in which the Poiseuille equation and Young-Laplace equation are used to calculate the pore radius. Based on the dual-porosity feature of landfilled waste, a SWCC equation is proposed by modifying the Van Genuchten equation. The pore-size distribution of landfilled waste is investigated. The results show that the modified equation can describe the water retention characteristics and the features of pores of landfilled waste very well. The saturated and residual water content of the municipal solid waste is high. The field capacity of shallow, middle and deep waste is 38.5%, 42.2% and 46.8%, respectively, corresponding to a matric suction range of 3~8 kPa. As the depth and age increase, the effective water content interval and specific yield decrease. Taking the matric suction of 1 kPa as the limit, the pores in waste can be devided into macropores and micropores. The probability density function of pore radius is bimodal. As the depth and age increase, the amount of macropores and their radiis decrease, at the same time, the amount of micropores increases and the average pore size becomes smaller.
- municipal solid waste /
- macropore /
- dual-porosity /
- soil-water characteristic curve

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参考文献(15)

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