Monitoring and environmental impact analysis of deep excavation of subway stations in river islands

For excavation of subway stations in river islands, some factors such as geological conditions, surrounding river levels and impact on the adjacent bridge structures should be taken into account. Available cases are scarce. For an excavation project of Juzizhou in Xiangjiang River of Changsha, the engineering geology, design and construction plan are analyzed. The layout of monitoring points, items and the predetermined warning values are discussed. According to the monitoring results, the measured internal force of struts, lateral movement of diaphragm wall, displacement of adjacent bridge are studied to evaluate their influences on the surrounding environment. Finally, the construction measures to ensure the safety of excavation and to reduce the influences on the surrounding environment are introduced, which are effective in construction of deep excavations in river islands.