好氧降解、应力和温度共同作用下填埋垃圾压缩变形规律及理论模型研究

The municipal solid waste (MSW) dumpsites are great in number and wide in distribution in China, which induced many environmental disasters and a serious waste of land resource. To achieve the goasl of harmlessness and resourcelization for the dumpsites, the processes of aerobic waste stabilization and subsequent site reuse are in demand. A sound understanding of the waste compression induced by aerobic degradation, stress and temperature is sorely required for the design and operation of waste stabilization and site reuse projects. In this research project, five sets of aerobic degradation-compression tests would be conducted on fresh waste samples, as well as three sets of creep and thermal deformation tests conducted on aerobic stabilized waste samples. They are performed to characterize the behaviors of the primary compression, aerobic biocompression, mechanical creep and thermal deformation, respectively. Then, a theoretical model would be proposed for predicting the compression strain of the waste pile, which concerns for the effects of aerobic degradation, stress and temperature. Finally, the model would be further developed to evaluate the settlement of the waste dumpsite under the aerobic degradation condition. The results of this research project would be favorable and helpful for the harmlessness and resourcelization of the thousands of waste dumpsites in China.

我国生活垃圾简易填埋场数量多、分布广，存在环境灾害事故时有发生、土地资源浪费严重等问题。好氧降解加速填埋垃圾稳定化后进行场地再利用是实现简易填埋场无害化和资源化的主要选择。深入研究好氧降解、应力和温度共同作用下填埋垃圾的压缩变形规律是保障简易填埋场加速稳定化和场地再利用工程科学设计和安全运营的基础。本项目拟开展5组新鲜垃圾好氧降解压缩试验以及3组稳定化垃圾蠕变压缩和热变形试验，揭示填埋垃圾的主压缩、好氧降解压缩、蠕变压缩和热变形发展规律，进而建立考虑好氧降解、应力和温度共同作用的填埋垃圾压缩变形理论模型，并提出简易填埋场在好氧降解条件下的沉降计算方法。本项目将为我国上万座简易填埋场的无害化和资源化处置提供支持。

我国生活垃圾简易填埋场数量多、分布广，存在环境灾害风险大、土地资源浪费严重等问题。好氧降解加速垃圾稳定化后进行场地再利用是实现简易填埋场无害化和资源化的主要选择。深入研究好氧降解、应力和温度共同作用下的填埋垃圾压缩变形规律及理论模型是保障加速稳定化和场地再利用工程的科学合理设计和安全高效运营的基础。. 本项目采用室内试验、理论分析、现场应用等手段对考虑好氧降解、应力和温度作用的填埋垃圾压缩变形规律及机理开展了研究，获得了以下研究成果：. (1) 揭示了生活垃圾的主压缩应变随应力的变化规律及关键影响因素；建立了以含水量、干重度和可压缩组分含量为主要参数的修正主压缩指数预测模型，并进一步拓展为能够预测修正主压缩指数随埋深的变化。. (2) 揭示了蠕变压缩应变随时间以及修正蠕变压缩指数随含水量、干容重、可降解组分含量和温度的变化规律，建立了考虑含水量、干容重和可降解组分含量综合影响的修正蠕变压缩指数预测模型。. (3) 揭示了降解压缩应变随时间、氧气条件、含水量、干容重和可降解物质含量的变化规律，以及修正降解压缩指数随温度的变化规律，改进了好氧降解压缩一阶速率模型；建立了生活垃圾好氧降解过程动力学模型，分析了含水量、温度、氧气浓度和垃圾组分对好氧降解压缩应变的影响。. (4) 以计算简便、拟合准确、预测合理和参数稳定为四个评价指标，建立了生活垃圾压缩模型综合评价体系；利用低厨余垃圾和高厨余垃圾大尺寸压缩试验数据，对9种典型压缩模型进行了评价分析，并分别推荐了适用于低厨余和高厨余垃圾填埋场的沉降预测模型。. 本项目最终揭示了生活垃圾的主压缩、蠕变压缩和降解压缩机理，提出了考虑好氧降解、应力和温度共同影响的沉降预测模型及其参数取值方法，能够为生活垃圾填埋场好氧降解加速稳定化和场地再利用工程的方案设计、现场施工和运营管理提供科学指导，具有较大的社会效益、环境效益和经济效益。