Influences Of Construction Methods On Crossing Underneath Overpass And Subway Station Integration

Along with the rapid development of Chinese economy, urban population surging and growing, more and more serious traffic congestion restricted the development of the city and affected normal life of people. Metro had became an important way to ease traffic pressure. Subway stations were generally built in neighborhoods with heavy traffic. Its excavation depth was generally reached more than tens of meters, because if an accident occurred, the consequences would be very serious. To ensure the safety of subway station construction, the most important thing was to make the security and stability in deep construction process.In this paper, the author explored and analyzed the following areas through numerical simulation and monitoring data processing comparison on the basis of the One line in Hefei, Mingguang metro station.(1)The article analyzed open-cut excavation and cover excavation of domestic and international research, elaborated the deformation mechanism of deep foundation pit, investigated on some of the important factors,such as deformation of retaining structure, excavation pit bottom uplift and uplift pile strength regular pattern. Besides, the article also summarized the current calculation method of deep foundation pit stability theory.(2)In this paper, the author used three-dimensional numerical simulation of open-cut method by Midas/GTS software, to carry out variation of the envelope structure, upheaval in the bottom and uplift pile axial force. By comparing the actual monitoring data to ensure that the outcome of the present value of the analog frequency was accurate and reliable.(3)To compare with the covered top-down excavation at the same conditions,it came out that envelope structure, upheaval in the bottom, uplift pile strength was basically the same trend with the open-cut method, but maximum results was smaller than the open-cut method. By comparison the three, the maximum value of the actual monitoring data was the smallest, covered top-down excavation was bigger followed by the largest open-cut method. It illustrated that actual construction of deep foundation pit excavation was in the safe and feasible range.In this project, the covered top-down excavation could be an optimizationprogram.