The West Link project in Gothenburg, Sweden, includes a 6.6 km long, shallow railway tunnel, which is under construction beneath the city center. As the groundwater level is approximately 1 to 3 m below the ground surface and also a significant portion of the tunnel is in clay, groundwater drawdown and ground settlement may occur. To understand the processes that could lead to groundwater drainage and land subsidence, we develop a 3D fully coupled hydromechanical model to capture the essential processes pertinent to drainage-induced settlement such as fluid flow, rock/soil consolidation, and stress redistribution. The model is built based on extensive site characterization data including geological mapping, lithological descriptions, topographical features, and geomaterial properties. We simulate the tunneling process reflecting different construction phases in situ. We compare the simulation land settlement results with the field monitoring values. The research findings of our work have important implications for underground construction in dense urban areas as well as other complex geological/geotechnical conditions.