填埋场生活垃圾焚烧飞灰的土力学特性

Geotechnical Properties of Domestic Waste Incineration Fly Ash from Landfill

我国生活垃圾焚烧飞灰逐年增加,大部分进入填埋场处置。然而关于飞灰的土力学特性研究相对较少,不利于指导飞灰填埋作业。对我国南方某填埋场稳定化焚烧飞灰的土力学特性进行了测试,并与前人的研究结果进行对比和分析。研究结果显示:生活垃圾焚烧厂原状飞灰属于级配良好粉土,经药剂、石灰、水泥稳定化固化处理后,颗粒大小逐渐增加,变为级配不良的粉砂、粗砂,甚至砂砾。不同填埋场飞灰的土力学特性差异较大,压缩系数αv1-2为0.26~2.96 MPa^(-1),压缩性等级为中等到高等级,黏聚力为8.00~19.47 kPa,摩擦角为32.5°~36.3°,重度为11.0~16.3 kN/m3。

The amount of fly ash from domestic waste incineration is increasing year by year,with the majority being disposed of in landfills.However,the research on the soil mechanical characteristics of fly ash was relatively few,which was not conducive to guiding the landfill operation of fly ash.The geotechnical properties of stabilized incineration fly ash from a landfill in south China were tested,and were compared with the results of previous studies.The results indicated that the original fly ash from the municipal solid waste incineration could be classified as well-graded fine soil.After being stabilized and solidified by chemicals,lime,and cement,the particle size gradually increased and transformed into poorly graded fine sand,coarse sand,or even gravel.The geotechnical properties of fly ash in different landfills showed significant variation.The compression coefficient αv1-2 of fly ash from different landfills ranged from 0.26 to 2.96 MPa^(-1).The compressibility grade was medium to high.The cohesion force was 8.00 to 19.47 kPa,the friction angle was 32.50~36.30,and the unit weight was 11.0 to16.3 kN/m3.