包气带中裂隙对轻非水相流体运移和分布影响的模拟研究

发布时间：2018-05-05 18:36

本文选题：LNAPL + 裂隙　；参考：《水利学报》2016年07期

【摘要】：岩土体中存在的大孔隙、裂隙等,使其呈现出强烈的非均质性。相比均质介质和不含裂隙的非均质介质,轻非水相流体(Light Non-aqueous Phase Liquids,LNAPLs)会优先通过裂隙管道进入土壤中,其运移规律更为复杂,造成的污染更为严重。为此,研究LNAPL在含裂隙基质中的运移与分布规律显得很有必要,研究成果将为裂隙发育区域的污染修复提供理论依据。本文通过室内试验和TOUGH2数值模型分析了裂隙对LNAPL运移及分布的影响。经过分析发现,LNAPL注入后,裂隙中的压强迅速增加,形成以裂隙为核心的、压强逐渐减小的辐射区;LNAPL优先流入裂隙中,以裂隙为核心向四周缓慢扩散,形成圈层状的饱和度逐渐减小的分布区;相同条件下,裂隙越长,同时刻LNAPL的污染面积越大,LNAPL到达饱水带的时间也越短;裂隙的存在,起到了"快速通道"的作用,使得LNAPL在短时间内渗入土壤中,造成严重的污染。
[Abstract]:The existence of macropores and fissures in rock and soil mass makes them show strong heterogeneity. Compared with homogeneous medium and heterogeneous medium without fissures, Light Non-aqueous Phase liquids (LNAPLs) of light and non-aqueous phase will enter the soil through fissure pipes preferentially, the migration law is more complex and the pollution is more serious. Therefore, it is necessary to study the migration and distribution of LNAPL in fractured matrix, and the research results will provide a theoretical basis for the remediation of pollution in fractured areas. In this paper, the effects of cracks on LNAPL migration and distribution are analyzed by laboratory tests and TOUGH2 numerical model. It is found by analysis that after injection of LNAPL, the pressure in the fracture increases rapidly, forming a radiation zone with a fissure as the core and the pressure decreasing gradually. The LNAPL preferentially flows into the fissure and diffuses slowly around the fissure as the core. Under the same conditions, the longer the fissure, the larger the pollution area of LNAPL at the same time, the shorter the time to reach the saturated zone, and the existence of the fissure acts as a "fast passage". LNAPL seeps into the soil for a short period of time, causing serious pollution.
【作者单位】：河海大学地球科学与工程学院;
【基金】：江苏省自然科学基金项目(BK2012814) 江苏省青蓝工程项目江苏省“六大人才高峰”项目(2014-JY-001)
【分类号】：X523

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