【作者】 冯国建；

【导师】 刘东燕；

【作者基本信息】 重庆大学 ， 岩土工程， 2010， 博士

【摘要】 随着国家城市化进程的加快和居民生活消费水平的提高,城市生活垃圾的增长速度十分迅速。结合我国国情,我国目前主要采用卫生填埋的方式对这些垃圾进行处理。在城市生活垃圾填埋过程中,由于有机物的降解以及上覆荷载的共同作用,城市生活垃圾填埋场会发生沉降变形,由此会对填埋场的设计、建设、运营以及开发利用造成一定影响,因此,必须对沉降问题予以足够重视。本文针对这一问题,主要进行如下研究工作:(1)垃圾土工程性质研究垃圾土工程性质的选用对填埋场设计、填埋单元的寿命及建设周期会产生很大影响。在广泛收集垃圾土工程性质研究资料的基础上,结合重庆市地理条件、经济发展水平、居民消费水平及气候条件,对重庆市城市生活垃圾的处理方式、产生情况、影响因素、工程性质和化学性质进行研究。(2)有机物降解影响因素试验研究根据重庆市城市生活垃圾的工程性质及组成特点,为避免现场取样的不均匀性及随机性,自配试样进行有机物降解试验研究。试验从试样质量变化的角度出发,根据试验时间及试样的质量变化描述试样的降解过程。在试验中,主要研究含水量、有机物颗粒尺寸及不同组分这三方面因素对降解的影响。通过试验,得到试样的质量变化模型及降解率模型。(3)有机物产气速率模型研究针对Scholl Canyon模型的不足以及我国城市生活垃圾产气速率衰减较快的特征,在假定条件下,依据有机物降解试验,分析试样质量减小的原因,结合降解过程中的反应方程式,采用分段函数的方法,在考虑了产气峰值之前的产气速率的情况下,建立有机物产气速率模型。(4)降解沉降模型研究在前人研究的基础上,从垃圾土内无机物的质量不发生变化这一角度出发,在考虑垃圾土降解率及密度变化的情况下,围绕垃圾土的密度、质量与体积三者关系,推导垃圾土一维降解沉降模型。该模型考虑了降解前后垃圾土的密度变化这一因素,揭示了降解沉降量与初始时刻垃圾土内有机物的体积百分含量、降解率以及初始高度这三者的关系。(5)耦合沉降模型研究假定城市生活垃圾填埋场为弹性体以及填埋气体和垃圾土骨架之间不存在热量交换,在不考虑流源和热源的情况下,根据饱和多孔介质的应力场方程、渗流场方程和温度场方程,进行一维情况下流-固-热耦合作用下的沉降模型研究,对该模型进行傅立叶变换及逆变换进行解析解求解,得到填埋场内部温度、孔压和变形的表达式。更多还原

【Abstract】 With the fast progress of urbanization and enhancement of living standard, municipal solid waste increases greatly. In light of China’s present situation, China deals with the garbage in way of sanitary landfill. However, problems brought with settlement should be given more attention in the construction, exploitation and operation of landfill sites. The paper mainly discusses the following aspects:(1) The study on engineering property of garbageThe choice of engineering property of garbage has a great influence on the design of landfill sites, the lifetime of landfill units and the construction circle. Basing on the wide accumulation of studying materials on engineering property of garbage, combine geographic situations, economic development level and weather conditions in Chongqing, we conduct the study in the ways of disposing rubbish , producing situation, influencing factors, engineering property and chemical nature of life garbage in Chongqing.(2) The study on factors influencing organic matter degradation of life garbageAccording to the engineering property of municipal solid waste and features of segments in Chongqing city, we start the experiment in the fixed changes of quality, the changing situations of sample quality in the process of the experiment was recorded and the procedures of organic matter degradation was described in order to avoid randomness and non-uniformity in choosing samples. In the experiment, we mainly discuss the following three parts including water content, the size of organic particles and different groups and analyse what impact the three parts give to degradation.Through the experiment, changing model of organic quality and degradation rate model of organic matter are obtained.(3) Study on the organic gas production rate modelAiming to the inefficiency of Scholl Canyon model and the fast decrease of gas production rate of municipal solid waste, in assumptive situations, according to the experiment of organic degradation, we analyse the decreasing reasons of sample quality, combine the reaction equation in the degradation process, take advantage of the sub-function and take the situation before the peak of gas production into consideration , as a result, establish the organic gas production rate model.(4) Study on the degradation settlement model In light of former study, we consider the rate of degradation and density of garbage and take its density, quality and volume into account and deduce one-dimension degradation- settlement model in the perspective of the fact that there is no changes in gas quality, The model pays more attention to the changes of density before and after degradation, shows the relationship between the amount of degradation, the percentage of organic matter in garbage , degradation rate and the initial height.(5) Study on the coupling settlement modelOne dimension fluid-mechanical-thermal coupled model was deduced under suppose the municipal solid waste landfill is elastomer and without considering the thermal source. Apply finite Fourier transform and its inverse transform to solve this model and got the expression of pore pressure, temperature and displacement.更多还原