软土地区地铁基坑承压水抽灌一体化模拟与分析

在地铁基坑施工中,承压水的控制对于基坑自身安全和周边环境保护至关重要。结合宁波轨道交通4号线儿童公园站基坑工程承压水控制实例,提出抽灌一体化的承压水控制方案。首先基于地下水三维非稳定渗流模型对承压水水位降深进行预测,以指导设计优化;进而基于抽水验证试验结果反分析承压水层的水文地质参数,研究抽灌一体化方案下基坑周边环境水位变化;最终利用数值模拟进行止水帷幕插入比和回灌井位置等设计参数影响分析。

Simulation and Assessment of the Confined Water Control of Pumping- Recharge Integration in the Subway Foundation Pit of Soft Soil Areas

In the construction of a foundation pit, it is essential to control confined water in order to ensure the safety of the pit and surrounding environment. A confined water control scheme for pumping-recharge integration is proposed in this paper and demonstrated via confined water control in the foundation pit project of Ningbo rail transit line 4, Children''s Park station. First, based on the three-dimensional unsteady seepage model of groundwater, the depth of the confined water level is predicted for optimizing the design; the hydrogeological parameters of the confined water layer are subsequently back analyzed using the results of the pumping verification test and the variation in environmental water level surrounding the foundation pit due to the pumping and irrigation integration scheme is further studied. Finally, numerical simulation is used to analyze the influence of design parameters, such as water stop curtain insertion ratio and recharge well position.