降雨工况下某山谷型垃圾填埋场变形稳定性分析

发布时间：2018-03-30 22:34

本文选题：垃圾填埋场　切入点：垃圾土力学特性　出处：《长沙理工大学》2015年硕士论文

【摘要】：近年来,我国城市生活垃圾产量正在以较快的速度增长,而卫生填埋是城市生活垃圾的主要处理方式,但垃圾填埋场的结构、垃圾土的组成及性质、库区环境都比较复杂,因此,合理分析垃圾体的物理力学特性,并准确评价垃圾填埋场的稳定性能,是有效综合处理城市垃圾中的关键环节。本文考虑到现实问题,对降雨条件下该垃圾填埋场在封场后封盖系统失效情况下的稳定性进行了预测研究。首先根据国内外填埋场垃圾土强度试验及稳定性研究文献和资料,结合该填埋场实际,进行概化分层,根据该地区城市生活垃圾成分表及推定的各层垃圾土物理特性,分别配制了三种不同孔隙比试样进行三轴力学试验,以获取垃圾试样的变形、强度参数。在试验成果基础上,建立垃圾堆积体概化地质模型,分析了降雨情况下该填埋场稳定性,此外,根据己有研究成果,总结了垃圾填埋场导排系统失效原因以及相应的处理措施,为保障其安全稳定提供指导,本文取得的研究成果具体如下:(1)通过文献研究,对我国不同地域的垃圾土三相指标进行了统计分析,得到了不同地域垃圾土的特点。(2)依据所研究垃圾填埋场的垃圾成份构成比例及其密实度状况,配制了孔隙比分别为3.0、2.5和2.0的垃圾土试样,以此反映该填埋场不同龄期、深度的垃圾土物理特性。通过三轴剪切实验可发现,垃圾土的粘聚力在14～17kPa之间,内摩擦角在24～35°之间。结合国内外已有研究成果及研究地区特殊的垃圾形成条件,该试验成果具有一定合理性。(3)采用弹塑性模型对垃圾坝及垃圾体在不同降雨工况下的三维应力场和位移场进行了计算分析;利用Bishop法计算了垃圾体边坡的稳定性,分析了垃圾坝在不同工况下的抗滑稳定性,得出了垃圾填埋场稳定性与降雨强度及其时序的关系。(4)降雨条件下垃圾坝稳定性主要受垃圾坝上游坡防渗系统的影响。垃圾坝上游坡防渗系统完好时,降雨对边坡垃圾坝下游坡稳定性影响较弱;垃圾坝上游坡防渗系统损坏后,降雨引起的渗滤液水位升高对边坡垃圾坝下游坡稳定性产生重要影响。(5)针对我国垃圾填埋场渗滤液水位壅高、导排系统失效以及淤堵情况严重的普遍现象,提出了渗滤液导排管防堵及清淤措施,并进一步阐述了强降雨情况下的应急处理措施,为垃圾填埋场的安全稳定运行提供借鉴和参考。
[Abstract]:In recent years, the output of municipal solid waste (MSW) in China is increasing at a relatively high speed, and sanitary landfill is the main treatment method of MSW. However, the structure of landfill site, the composition and nature of MSW, and the environment of reservoir area are all complicated.Therefore, it is a key link to analyze the physical and mechanical properties of garbage and evaluate the stability of landfill.In this paper, considering the practical problems, the stability of the landfill under the condition of rainfall is predicted under the condition of the failure of the sealing system after the sealing site.Firstly, according to the strength test and stability research literature and data of landfill soil at home and abroad, combined with the actual situation of the landfill site, the general stratification is carried out. According to the composition table of municipal solid waste in this area and the physical characteristics of each layer of garbage soil,In order to obtain the deformation and strength parameters of garbage samples, three kinds of samples with different void ratios were prepared for triaxial mechanical tests.Based on the experimental results, a generalized geological model of garbage accumulation is established, and the stability of the landfill under rainfall is analyzed. In addition, according to the existing research results, the causes of failure of the landfill guiding and drainage system and the corresponding treatment measures are summarized.In order to provide guidance for its safety and stability, the research results obtained in this paper are as follows: 1) through literature research, the three-phase indicators of garbage and soil in different regions of China are statistically analyzed.According to the proportion of garbage composition and compactness of the landfill site studied, the waste soil samples with porosity ratio of 3.0% 2.5 and 2.0% were prepared to reflect the different ages of the landfill site.The depth of the garbage soil physical properties.Through triaxial shear experiments, it is found that the cohesive force of garbage soil is between 14~17kPa and the angle of internal friction is between 24 掳and 35 掳.Combining the existing research results at home and abroad and the special conditions for garbage formation in the research area,The test results are reasonable. The elastic-plastic model is used to calculate and analyze the three-dimensional stress field and displacement field of refuse dam and solid waste under different rainfall conditions, and the stability of refuse slope is calculated by Bishop method.The stability of refuse dam under different working conditions is analyzed. It is concluded that the stability of landfill site is mainly affected by the anti-seepage system of upstream slope of refuse dam under the rainfall condition and the relationship between the stability of landfill site and rainfall intensity and its time series.When the seepage control system of upstream slope of refuse dam is intact, the effect of rainfall on the stability of slope downstream of refuse dam is weak, and after the seepage control system of upstream slope of refuse dam is damaged,The increase of leachate water level caused by rainfall has an important influence on the slope stability downstream of the slope refuse dam. (5) aiming at the common phenomena of high leachate water level, failure of guiding and drainage system and serious silting situation, the leachate water level in landfill sites in China is high, and the situation of blockage is serious.The anti-blocking and silt cleaning measures of leachate guide and discharge pipe are put forward, and the emergency treatment measures under the condition of heavy rainfall are further expounded, which can provide reference and reference for the safe and stable operation of landfill site.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X705

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