考虑孔洞随机分布的垃圾填埋场HDPE膜覆盖层填埋气运移机理研究

针对生活垃圾填埋场填埋气击穿HDPE膜发生逸散这一工程问题，以HDPE膜的气体扩散系数与膜下垃圾气体释放通量为研究对象，采用室内试验，理论分析与现场试验相结合的方法，研究分别经过高温、强紫外线老化后HDPE膜的气体扩散系数与现场尺度的HDPE膜下垃圾的气体释放通量。分析在水平拉力作用下，不同老化阶段的HDPE膜气体扩散系数变化规律，膜下垃圾的气体释放通量变化规律、影响因素及膜下的气压累积状态，阐明拉力-环境因素耦合对HDPE膜气体扩散系数的影响机理与考虑膜下气压累积的填埋气运移机理。项目预期将探明填埋气击穿HDPE膜的过程与影响因素，通过建立考虑膜孔洞随机分布的填埋体-间隙-膜三层体系的填埋气运移模型，完整揭示HDPE膜下填埋气的运移机理。项目的实施可为我国生活垃圾填埋场填埋气无组织逸散控制方案的优化提供科学依据。

Aiming at the problem of landfill gas (LFG) leakage by transporting through HDPE geomembrane (GM) on domestic waste landfill, the variation of GM diffusion property and gas emission rate beneath the GM were set as the research objects. By using the laboratory tests, theoretical analysis and field teats, the GM diffusion property under high temperature, high ultraviolet radiation and the gas emission rate of the waste beneath the GM in full-size scale were investigated. The variation regularity of GM diffusion property in aging stages under horizontal tension were analyzed. The variation characteristics and influencing factors of gas emission rate of MSW beneath the GM were also discussed. Finally, the influence mechanism of GM diffusion property variation under environmental factors- horizontal tension coupled condition and migration mechanism of landfill gas with the accumulated pressure beneath the GM would be proposed. The project is expected to reveal the process and influencing factors of landfill gas migration through the GM and establish a landfill gas migration model of Waste-Gap-GM three-layer system, consider the hole random distribution on the GM. The results of this research project could reveal the mechanism of gas leakage by transporting through the GM and provide the scientific basis for the optimization of the existing gas leakage control methods on domestic waste landfill in China.