陆海军,栾茂田,张金利.垃圾填埋场ET封顶系统水分平衡数值分析[J].,2009,(6):913-918 |
垃圾填埋场ET封顶系统水分平衡数值分析 |
Numerical simulation of moisture balance in evapotranspiration landfill cover |
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DOI:10.7511/dllgxb200906024 |
中文关键词: 蒸发传输 垃圾填埋场 封顶系统 含水率 |
英文关键词: evapotranspiration landfill cover system moisture content |
基金项目:国家自然科学基金资助项目(5063901050678032). |
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中文摘要: |
针对垃圾填埋场压实黏土最终封顶易受气候影响而开裂(干裂缝或冻融裂缝),其工程特性显著降低的缺陷,介绍了新型ET(蒸发传输)封顶系统的工作机理.在同时考虑降水和蒸发补给的作用下,建立了水汽在ET封顶系统迁移的一维数学模型.以大连市1976年的降水和蒸发补给气候条件为边界条件,模拟了ET封顶系统中的水汽在1 a内变化规律.从分析模拟结果得出,距地面越近含水率受降水、蒸发补给气候条件的影响越显著,且随着深度的增加出现明显的峰值滞后现象.阻隔土壤层中的水分未达到饱和状态,说明总厚为150 cm的ET封顶系统完全可以抵御大连市近48 a以来最大强降水的冲击.对降水强度、降水持续时间以及阻隔层的厚度等参数进行了分析.数值分析与试验数据对比结果表明,计算值和试验数据基本吻合,验证了模型的可靠性.研究工作为建造垃圾填埋场ET封顶系统提供了理论依据. |
英文摘要: |
The compacted clay cover systems of landfills were studied for desiccation cracks (dry crack or thowing crack for climate). The mechanism of a new type of evapotranspiration cover was analyzed to promote the engineering performance. On the basis of considering precipitation and evaporation, a one-dimensional dynamic model was developed for simulating moisture transport in evapotranspiration landfill cover. Volumetric water content was simulated based on the data of precipitation and evaporation of Dalian in 1976. Result of simulation is analyzed. It is apparent that the moisture content near the surface is highly sensitive to climate loading, but the effect is significantly attenuated and time-lagged along with increasing depth. Moisture content of barrier soil layer is partially saturated. Evapotranspiration landfill cover (thickness:150 cm)is absolutely able to resist strong precipitation which is the heaviest one in 48 a of Dalian. Parametric analyses are conducted to simulate variations in precipitation rate, precipitation event duration and barrier soil layer thickness. The experimental data are used to provide a quantitative verification of the model. The model simulations are compared with the data, which reasonably agree with model simulation. The simulation model provides scientific evidence for building evapotranspiration landfill cover. |
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