地下构筑物内空气氡浓度监测及影响因素分析研究  

Monitoring and impact analysis of the radon concentration in the underground structures

作　　者：赵海洋 连培聪 李鑫 李彦恒 王光杰[2] ZHAO HaiYang;LIAN PeiCong;LI Xin;LI YanHeng;WANG GuangJie(Rocket Force Institute of Engineering Design and Research,Beijing 100011,China;Institute of Geology and Geophysics of Chinese Academy of Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]火箭军工程设计研究院,北京100011 [2]中国科学院地质与地球物理研究所,中国科学院大学,北京100049

出　　处：《地球物理学进展》2023年第2期950-957,共8页Progress in Geophysics

摘　　要：氡是地下构筑物中广泛存在的一种放射性污染物,因潜在危害大、健康风险高而备受关注.为探明氡浓度影响规律,制定针对性防控措施,通过监测两类6个地下构筑物内空气氡浓度,研究了氡浓度影响因素.监测结果表明,除4#构筑物存在短时氡浓度超标现象外,其他5个地下构筑物氡浓度均符合有关标准要求.分析研究发现,构筑物内空气氡浓度水平与以下因素有关:(1)工程地质.B区地层岩性比A区更有利于形成较高氡浓度,且B区地下水比A区埋深更浅、更丰富,更利于地层深处的氡迁移和扩散至地表,故B区构筑物内氡浓度普遍较高;(2)部位埋深.岩土中氡浓度随岩土深度的增加呈现上升趋势,且靠近外侧的口部通风状况优于中段和内侧,有利于空气中氡的扩散稀释,故构筑物埋深越浅,其氡浓度越小;(3)施工活动.现场凿挖岩体会释放氡,增加氡浓度;施工产生的扬尘进入测氡仪电离室腔体内,造成计数误差增大;(4)被覆状态.被覆层能够阻止氡的析出,厚度越厚,氡析出率越小;(5)建造样式.坑道式构筑物四面均被岩石包围,而覆土式构筑物只有底面为岩石,前者比后者更容易形成高氡环境.Radon is one of the radioactive pollutants existing in the underground structures and causes lots of attention due to its potentially important threat on human health. In order to investigate the impact rules of radon and formulate targeted prevention and control measures, the radon concentration was monitored in two types of six underground structures, and its influence factors were analyzed. Results indicated the radon concentration in five of the six structures met the requirements of relevant standards except for the 4# structures in short period time. Analysis revealed that the radon concentration is affected by following factors:(1) Engineering Geology. Lithology in B area, which is more suitable than that in A area for high radon concentration, and the shallower and richer groundwater in B area, which profit to migrate and diffuse the radon in the deep ground, are responsible for the high radon concentration in the underground structures.(2) Burial Depth. The radon concentration increases with the rock and soil depth, and the outer region is conducive to the radon diffusion into the air. Thus, the radon concentration increases with the burial depth of the structures.(3) Construction Activities. Rock chiseling will release the radon and increase the radon concentration. Also, dusts produced from the activities accidentally enter the chamber of radon measuring instrument and causes distinctly large error.(4) Lining State. Lining layer can prevent the radon from exhalating, and the radon exhalation rate decreases with the lining thickness.(5) Building Pattern. Tunnel structures are enclosed by rocks from all direction, while the covered structures stand on the rock bottom. The former is easier to form a high radon environment than the later.

关 键 词：地下构筑物 氡浓度 地质 被覆 

分 类 号：P631[天文地球—地质矿产勘探]