稳定化垃圾焚烧飞灰的水力-力学特性测试及其堆体稳定性分析  

Hydraulic-mechanical characteristic test of stabilized MSWI fly ash and stability analysis of its pile

作　　者：钱剑文 徐辉 缪建冬[1] 陈萍 QIAN Jianwen;XU Hui;MIAO Jiandong;CHEN Ping(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,China;MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江理工大学建筑工程学院,杭州31OO18 [2]浙江大学软弱土与环境土工教育部重点实验室,杭州310058

出　　处：《浙江理工大学学报（自然科学版）》2021年第1期126-135,共10页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：国家自然科学基金项目(51578508);住房和城乡建设部科学技术计划项目(2015R3002)。

摘　　要：对稳定化垃圾焚烧飞灰(稳定化飞灰)填埋场进行稳定性评估是保障填埋场长期安全运营的关键,而稳定化飞灰的水力-力学特性是进行稳定性评估的重要参数。为掌握稳定化飞灰在水力-力学特性方面的特征,以南京某稳定化飞灰填埋场为工程对象,测试了0~11个月龄期范围内稳定化飞灰的水力-力学特性,并与生活垃圾进行了对比。研究结果发现:稳定化飞灰的重度为11.0~12.3 kN/m~3,内摩擦角为32.9°~34.2°,两者的龄期效应均不明显;黏聚力在14.0~19.5 kPa之间,随龄期的增长呈下降趋势;随着埋深的增大,残余体积含水量呈增大趋势,进气值呈减小趋势,而土水特征曲线变陡;当初始孔隙比为1.60~2.15时,饱和渗透系数为9.20×10^-6~3.82×10^-5m/s。在此基础上,采用Geo-Studio软件分析了降雨、坡高、坡比、渗滤液水位等对稳定化飞灰堆体稳定性的影响。结果发现:平均型、前峰型和中峰型降雨模式在降雨前期对稳定性影响较大,后峰型降雨模式在降雨后期对稳定性影响较大。随着填埋高度或坡比的增大,稳定安全系数逐渐减小。随着相对渗滤液水位的提高,稳定安全系数显著下降且下降速度越来越快。稳定化飞灰在水力-力学特性及其龄期效应方面均与生活垃圾存在差异,对稳定化飞灰填埋堆体进行稳定性评估时,不可盲目采用生活垃圾填埋场相关规范及推荐参数。The stability assessment of stabilized MSWI(municipal solid waste incineration)fly ash landfills plays a crucial role in keeping the long-term safe operation of landfills,and the hydraulic-mechanical characteristics of stabilized fly ash are the key parameters in the stability assessment.To grasp the hydraulic-mechanical characteristics of stabilized fly ash,a stabilized fly ash landfill in Nanjing was chosen as a research object to test the hydraulic-mechanical characteristics at filling ages of 0~11 months,and the comparison with household waste was conducted.The test results showed that,the weight of stabilized fly ash was in the range of 11.0~12.3 kN/m3,and the internal friction angle was ranged from 32.9°to 34.2°.The filling age effect of both was not obvious.The cohesion of stabilized fly ash was in the range of 14.0~19.5 kPa,and decreased with the increase of filling age.As the burial depth of stabilized fly ash increased,the residual volume water content increased,and the air entry value decreased,while the soil water characteristic curve became steeper.When the initial void ratio was 1.60~2.15,the saturated permeability coefficient was 9.20×10^-6~3.82×10^-5 m/s.On this basis,the effects of rainfall,slope height,slope rate and leachate level on the pile stability of stabilized fly ash were analyzed by using the Geo-Studio software.It was found that,in the earlier stage of rainfall,three rainfall types(average,front peak and middle peak)had a significant impact on the pile stability,while in the later stage of rainfall,the back-peak rainfall type affected the pile stability most.The safety factor decreased gradually as the slope height or the slope rate increased.As the relative leachate level increased,the safety factor declined significantly and the speed of falling became faster and faster.Stabilized fly ash differed from household waste in terms of hydraulic-mechanical characteristics and aging effect.During assessing the stability of stabilized fly ash landfill system,relevant specification and th

关 键 词：稳定化垃圾焚烧飞灰 水力-力学特性 堆体稳定性 降雨 坡高 坡比 渗滤液水位 

分 类 号：X705[环境科学与工程—环境工程]