贵阳地区地铁建设地下水处理措施研究

Research on Treatment Measures for Groundwater During Constructing Guiyang Metro

针对贵阳地区地形地貌较复杂、岩溶与裂隙发育、地下水丰富且补给广泛的特点,结合贵阳地铁建设中揭露的地下水情况,对贵阳地铁基坑及隧道开挖的地下水处理措施进行总结分析.通过分析得出,贵阳地铁岩质基坑采用坑外截水沟+坑内集水明排的地下水处理措施大体是合适的,不会带来场区大范围的地面沉降,具有广泛的适应性,但不可不加分析地生搬硬套;对于岩溶管道水丰富、裂隙发育的地铁区间隧道,常规的反应式局部注浆止水方案在实施过程中常带来新的渗水点,注浆止水工作需反复进行、费时费力,且效果较差,分区注浆止水措施具有明显优势,是未来发展的一个方向;因隧道二衬施工环境的限制,防水板的铺砌、止水带的埋设及二衬混凝土的浇筑难以在完全满足要求的条件下实施,故二衬结构施工缝位置处防水一直是一个薄弱环节,故建议加强富水地区隧道二衬施工缝处防水措施.

In light of the characteristics of complex topography landforms,developing karst and fracture,abundant groundwater and extensive recharge in Guiyang area,the groundwater treatment measures of Guiyang metro foundation pit and tunnel excavation are summarized and analyzed in consideration of the groundwater exposed in the construction of Guiyang metro.It is concluded that the groundwater treatment measures adopted in the rock foundation pit of Guiyang metro are generally appropriate without bring large range land subsidence,and have a wide range of adaptability,however,it could not be applied without analysis.For metro tunnels with abundant karst conduit water and developed fissures,the conventional local ejection for water plugging often brings new seepage points in the implementation process.The ejection for water plugging work needs to be repeated,time·consuming and laborious,and the effect is poor.The ejection for water plugging by partition has obvious advantages,which is a direction of future development.Because of the restriction of the construction environment of secondary lining,the paving of waterproofing board,burying of water-stopped belt and pouring of secondary lining concrete are difficult to implement and fully meet the requirements under the condition.Therefore,the waterproofing at the construction joints of the secondary lining structure has always been a weak link.It is suggested to strengthen the waterproofing measures at the construction joints of the secondary lining of the tunnel in water abundant area.