地铁工程建设对地下水流场影响分析:以北京地铁十二号线为例

ANALYSIS OF INFLUENCE OF SUBWAY CONSTRUCTION ON GROUNDWATER FLOW:A CASE OF METRO LINE 12 IN BEIJING

为解决城市日益拥堵的交通问题,地铁工程建设在我国各大城市如火如荼的开展。随着地铁工程埋深的加大,为保障施工安全,车站区段施工期间需要采取降水措施,对周边的地下水流场产生影响,并且,地铁建成后,由于其隧道和车站的阻水特性,将引起地铁沿线两侧的区域流场变化,产生类似的“水坝”效应。以北京地铁十二号线为例,利用Modflow软件建立地下水数值模型模拟了典型车站施工期间降水引起的周边流场变化以及地铁运营后沿线流场变化,重点分析了地铁建设对周边水源井及建筑的影响。结果表明:地铁12号线工程建设期对地下水水位和流场仅局限在铁路沿线742 m范围内,影响范围有限,短时间内容易恢复,对地下水资源影响小,且施工降水对沿线水源厂取水井的影响不大,地铁12号线工程运营期引起地下水位下降或抬升幅度较小,一般在9 cm以内,对地下水的流向改变程度不大。以期为地铁建设对地下水流场影响的评价问题提供参考。

In order to solve the traffic jam of cities,subway engineering is constructed in China’s major cities.With the increase of the depth of the subway project,in order to ensure the construction safety,precipitation measures need to be taken during the construction of the station,which will inevitably have an impact on the surrounding groundwater flow field.Moreover,after the completion of the subway,due to the water blocking characteristics of the tunnel and the station,the regional flow field along the subway will change,resulting in a similar"dam"effect.