降雨条件下某垃圾填埋场饱和—非饱和渗流场特性研究

发布时间：2018-01-05 17:24

本文关键词：降雨条件下某垃圾填埋场饱和—非饱和渗流场特性研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：国内大部分垃圾填埋场存在表层覆盖层破坏以及排水设施淤堵问题,在降雨条件下雨水直接进入填埋场而未能有效排出,导致填埋场水位升高引起堆体暂态水压力过大。现有研究表明垃圾堆体暂态水压力过大是引起垃圾体失稳的重要原因之一。为了解垃圾填埋场在降雨条件下的暂态地下水位变化特性以及垃圾坝坝前水荷载分布情况,基于西南地区某垃圾填埋场垃圾土成分构成,对不同孔隙比垃圾土进行非饱和渗透试验研究以及二维、三维渗流场数值计算和研究,本文主要研究工作和结论如下:(1)通过文献研究,归纳总结了国内外垃圾填埋场渗滤液运移变化规律,研究了垃圾填埋场渗流导致的工程破坏的机理和机制。(2)采用室内饱和渗透试验和非饱和渗透试验方法分别研究了孔隙比为2.0、2.5和3.0的垃圾土饱和—非饱和渗透特性,研究表明:室内试验中垃圾土因存在的大量有机成分是导致垃圾土非饱和渗透系数和残余含水量偏大的主要原因。(3)采用饱和非饱和非恒定渗流理论研究了某垃圾填埋场在不同降雨条件下的地下水位分布和变化特性以及垃圾坝前水荷载分布情况,研究成果表明:填埋场在降雨前的初始渗滤液水位(对应填埋场渗滤液导排系统工作状态)对运行过程中降雨入渗导致的水位升高、垃圾体内的孔隙水压力及坝前水荷载分布有重要影响;规模较小的山谷型填埋场在遭遇暴雨和久雨情况下,渗滤液水位将快速抬升,并在填埋场中形成过高的暂态地下水位;降雨总量相当情况下,连续久雨比短时暴雨对填埋场稳定性更为不利。(4)通过对垃圾填埋场渗流场变化过程的动态分析,研究了垃圾坝坝前水荷载的空间分布规律,为垃圾坝稳定性分析提供了基础资料。
[Abstract]:Most of the landfills in China have the problems of overburden destruction and blockage of drainage facilities. Rain water enters the landfill directly under rainfall conditions and can not be discharged effectively. The current research shows that excessive transient water pressure is one of the important reasons for the instability of refuse. In order to understand the transient water pressure in the landfill site under rainfall conditions, one of the important reasons. The variation characteristics of groundwater level and the distribution of water load in front of refuse dam. Based on the composition of refuse soil in a landfill in southwest China, unsaturated permeability test and numerical calculation and study of two-dimensional and three-dimensional seepage field were carried out for different void ratios. In this paper, the main research work and conclusions are as follows: (1) through the literature research, summarized the domestic and foreign landfill leachate migration changes. The mechanism and mechanism of engineering failure caused by landfill seepage were studied. (2) the porosity ratio of 2.0 was studied by indoor saturated permeability test and unsaturated permeability test. 2. 5 and 3. 0 saturated-unsaturated permeability of MSW soil. The results show that the large amount of organic components in the MSW soil is the main reason for the high unsaturated permeability coefficient and residual water content in the MSW soil. The distribution and variation of groundwater level in a landfill under different rainfall conditions and the distribution of water load in front of a refuse dam are studied by using saturated unsaturated unsteady seepage theory. The research results show that the initial leachate water level (corresponding to the working state of landfill leachate guide and drainage system) in the landfill before rainfall increases the water level caused by rainfall infiltration. The pore water pressure and the distribution of water load in front of dam play an important role in MSW. In the case of heavy rain and prolonged rain, the leachate water level will rise rapidly in the small valley landfill, and the transient groundwater level will be too high in the landfill. When the rainfall amount is equal, the stability of landfills is more unfavorable than that of short term rainstorm.) the dynamic analysis of the seepage field variation process of landfill site is carried out. The spatial distribution of the water load in front of the refuse dam is studied, which provides the basic data for the stability analysis of the refuse dam.
【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】：TU43

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