Abstract:In the complex transportation hub area of urban airports, how to comprehensively and effectively control the composite confined aquifer appearing in ultra-deep foundation pits has become a key technical problem that must be solved in the excavation construction of ultra-deep foundation pits in Shanghai. Pudong Airport Station of the airport liaison line in Shanghai is located directly below the main road - Yingbin Avenue of the airport in the core area of the transportation hub of Shanghai Pudong Airport. The stratum in the range of the project foundation pit is affected by the cutting of ancient river channels, and the north-south geological conditions fluctuate greatly. Layers ⑥ and ⑧ are missing, and layers ⑦ and ⑨ are connected by confined water. The distance between the main structure of the station and the adjacent pile foundation of the maglev is only 26.5 m, and the surrounding environmental protection requirements are also very high. In order to meet the dual safety of the foundation pit and the environment, the integrated design of enclosure and dewatering for the composite confined aquifer group is carried out in the project, and then is verified and analyzed through the pumping tests to ensure the reliability of the implementation of the dewatering scheme. Through the dynamic control in the excavation stage of the foundation pit, the expected goal to control the confined water is finally achieved.
