广珠城际珠海站基坑降水及周边环境保护

The Foundation Pit Dewatering and the Environment Protection at Zhuhai Station of Guangzhou-Zhuhai Intercity Railway

广珠城际珠海站降水项目采用三维有限元渗流计算,建立三维空间上的非均质各向异性水文地质概念模型来预测基坑开挖过程中的地下水位等值线和周边地面沉降,并采取合理的降水手段,科学设计、精心施工和严格管理,对坑内承压水进行"按需减压"降水,根据减压井抽水量及减压观测井的承压水位,确定开启的减压井数量,合理控制承压水水位。对坑外采取人工回灌措施,最大限度的抬升坑外水位,使整个基坑坑外的水位下降值处于完全可控状态,在一定程度上控制了地面沉降,将减压降水对环境的影响控制到最低程度,确保了深大基坑安全开挖和大底板正常施工,同时保证了周边环境的安全和稳定,回灌也取得预期效果。

The three-dimensional, non-homogeneous, anisotropic hydrogeological conceptual model in the dewate- ring project at Zhuhai station of Guangzhou-Zhuhai intercity railway was used to predict the water table contours and ground subsidence during the excavation and reasonable means of dewatering to pit confined water were taken by sci- entific design, careful construction and strict management with i, decompression according to the need of precipitati- on＂, on the basis of open the relief well pumping volume and pressure of the confined water level of observation wells, to determine the quantity of relief well, reasonable control of confined water level. The artificial recharge is taken outside the pit, to reach the maximum uplift water level outside the pit and the drawdown value outside the pit is in completely controllable state, to a certain extent the ground settlement, the vacuum precipitation influence on en- vironment is restricted to a minimum, to ensure the safety of deep foundation pit excavation and normal construction of large baseplate, but also ensure the surrounding environment to be safe and stable, and get the expected effect of re- charge.