城市生活垃圾变形特性影响因素的试验研究  

Factors influencing long-term settlement characteristics of the municipal solid waste

作　　者：孙秀丽[1] 孙秀伟[2] 金立乔[1] 

机构地区：[1]江南大学环境与土木工程学院,江苏无锡214122 [2]唐山学院机电工程系,河北唐山063000

出　　处：《安全与环境学报》2011年第5期94-98,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51009071);江苏省自然科学基金项目(BK2010144);江南大学自主科研青年基金项目(JUSKP111A14)

摘　　要：为了进一步研究城市生活垃圾(MSW)的长期变形特性,探讨初始孔隙比、易降解有机物质量分数和降解条件对其变形特性的影响,采用自主研制的压缩一降解仪,进行了多种工况下MSW的蠕变变形试验。结果表明,荷载水平较低时,初始孔隙比越小,孔隙比随竖向荷载减小的速率越快;当密实到一定程度时,孔隙比随荷载的增加有趋于稳定的趋势。易降解有机物质量分数越大,MSW的压缩模量越小,变形量越大。在竖向应力较小时,降解条件对MSW的变形特性影响不大;当竖向应力较大时,降解条件对MSW的变形特性有显著的影响。MSW的变形是应力与降解耦合作用的结果,降解引起的变形要靠应力作用才能实现,同时降解对MSW试样的压缩模量有较大的影响,并且影响MSW的应力状态。因此,初始孔隙比、降解条件和易降解有机物质量分数不但对MSW的最终变形量有较大的影响,同时对MSW沉降变形过程也有显著的影响。The paper has done a series of experimental tests to inves- tigate long-term settlement consequences of municipal solid waste （MSW） by using self-made compaction-degradation equipment. For our research purpose, we have done tests based on the assessments of one-dlmensional compression on MSW samples with different initial void ratio and various organic wastes in the conditions conducive to the microbial at high temperature and leachate recirculation and a- gainst degradation conditions according to Chinese in-situ in composi- tion and disposal of MSW. The results of our investigation confirm that when measuring the initial void ratio of 4 （the largest one） under vertical stress, greater and equal settlement rates were found for less than and larger than 50 kPa in size respectively. Stable void ratios were found to reach 0.19 and 1.64 for the initial void ratios of 4 and 2 separately under the compaction with vertical stress of 200 kPa. The ratio tends to decrease to 1.8 and 1.41 of MSW with organic matter content of 15% and 75% under the vertical stress of 100 kPa respectively, whereas the corresponding settlement rates were able to reach 10% to 29.5%. Larger settlement rates can also be made to reach for the waste with higher organic content when compacted at various stress levels, which indicate that the presence of organic con- tent in MSW not only gives rise to the problem of reducing the initial compression modulus but also making up for the increase of the mod- nlus caused by compaction under vertical stresses. The actual situa- tion is that in the low stress stage （ 〈 25 kPa） of compaction, the set- dement rate would have nothing to do with the degradation condition and the degradation influence at the great stress levels, which tends to p^ve that the mutual interaction of degradation and stress has to be taken into account when studying the long settlement characteristics of MSW. In fact, the above said factors are expected to be capable of acting on or affecting each other and therefore fur

关 键 词：环境工程学 城市生活垃圾 压缩一降解 初始孔隙比 易降解有机物 降解 

分 类 号：X705[环境科学与工程—环境工程]