某地下建筑物空气氡浓度水平特征
Radon Concentration in an Underground Space
-
摘要:
目的 选择上海市虹桥-五角场断裂构造背景下的地铁站站台、地下商城(商业街)和地下停车库, 对公共空间环境空气氡浓度现状进行调查与评价。 方法 地下建筑物空气氡浓度采用电子测氡仪(RAD-7)测定。 结果 上海新客站站台空气的氡浓度水平<3.3~16.2 Bq/m3, 地下商场(商业街)的氡浓度水平<3.3~13.0 Bq/m3, 地下停车库<3.3~8.84 Bq/m3;高铁虹桥站地下停车库空气的氡浓度水平仅<3.3~4.25 Bq/m3。 结论 虹桥-五角场断裂自中更新世以来暂停了构造活动, 失去了上达地表的通道, 以及上覆第四纪松散沉积物盖层的过滤和吸纳作用, 造成分布于该断裂背景的地下建筑公共空间不具备形成高氡浓度水平的地质因素, 致使分布于该地质背景的地下建筑公共空间环境氡浓度水平低于上海市地下建筑公共空间环境空气氡浓度水平, 更低于之前的上海市地下工程空气中的氡水平调查值。 Abstract:Objective To evaluate the radon concentration in an underground public space under the background of Hongqiao-Wujiaochang fault structure, including subway stations, shopping malls, and parking lots. Methods The radon concentrations in underground public space were measured by electronic radon monitor(RAD-7). Results On the underground level of Shanghai Railway Station, the radon concentrations were in the range of <3.3-16.2 Bq/m3 for the platforms, <3.3-13.0 Bq/m3 for the shopping malls, and <3.3-8.84 Bq/m3 for the parking lots. The radon concentrations of the underground parking lots of Hongqiao High speed Railway Station were <3.3-4.25 Bq/m3. Conclusion As the result of Hongqiao-Wujiaochang fault structure suspending its tectonic process since Middle Pleistocene, the possibility of radon channeling up to the ground surface declines. In addition, the filtration and adsorption effects of overlying loose sediment cap since Quaternary result in even lower radon concentrations in the studied underground spaces than the average radon level in similar spaces in Shanghai or the results from previous published similar studies.
下载:
