Study On The Influence Of Dewatering At Hanoi Tran Hung Dao Station On Land Subsidence

In this paper,the precipitation at Tran Hung Dao station is calculated and the impact of precipitation engineering on land subsidence is analyzed.The tasks and achievements of this study are as follows:1.The geological and engineering conditions near the Tran Hung Dao Station wereinvestigated and methods for the precipitation and support of the foundation pits were summarized.Factors affecting the dewatering of the foundation pits were analyzed using an induction method including geological conditions,hydrogeological conditions and pumping volumes of foundation pit enclosure structure.2.According to the characteristics of the groundwater of project,well arrangement of the Tran Hung Dao Station in Hanoi was designed.The precipitation wells are evenly arranged at the edge of the foundation pit.A total of 28 wells have a well depth of 35m and a well spacing of 18m.The type of precipitation well is a complete well for submersion.According to Technical Regulations for Building Foundation Pit Support the water inflow for the foundation pit of the Hanoi subway station is calculated to be Q=3025.7m³/d and the single well output capacity of the well is q₀=140.03m³/d and the surrounding area is calculated.The maximum ground settlement value is 3.2cm.The ground settlement has little impact on the foundation pit construction and will not endanger construction safety.The finite element software Visual Modflow was used to simulate the excavation and dewatering of the foundation pit according to the geological conditions of the project and the parameters of the hydrogeological conditions.The percolation path reflects the precipitation funnel curve of the surrounding project and draws the water level contour.3.Visual Modflow software was used to simulate the excavation and dewatering of foundation pit according to the geological conditions and hydrogeological conditions of the project.The percolation path reflects the precipitation funnel curve of the surrounding project and draws the water level contour.Using Visual Modflow software to simulate the precipitation process and the analysis of the changes in the nearby strata,accurate and intuitive to see the changes in the water level.