Study On Construction Schemes Of The Subway Station Constructed By Shield Method Combined With Cut And Cover Method

The distinguishing features of shield drvien method such as its small impact on the environment; safe and fast; and applicable to a wide range of situations, make it become the very important method of urban underground railway construction. However, in the actual subway construction, due to the short distance between the subway station, the tunnel constructed by the shield method is shorter in the length with the shorter construction period. Inevitably, the phenomenon like shield interval dispersion and low utilization rate of shield equipment would increase the cost of the project. Combined shield method to expand excavation with the construction of subway station could generate economies of scale to solve above problems by the long-distance applications of the shield machine. Then the project cost can be substantially reduced in general. To this end, this thesis proposes a construction program based on the developed shield tunnel with combination of cut and cover method of construction of subway station.Based on the comprehensive analysis of the foreign adoption of shield method on the subway station construction, the thesis discusses the application of shield method combining cut and cover method on the subway station construction, using the Chengdu Metro Line 1 Fuhuayuan station as a numerical analysis background. The mainly study content are as follows:Through the analysis of domestic and international engineering practice, the thesis develops a plan for subway station structure and size, and then designs the block segment for shield tunnel segment;Discusses the embedded depth of diaphragm wall and other supporting construction methods during expanding excavation, using numerical simulaiton. The author obtains the law of impact of reasonable embedded depth of the diaphragm wall and the auxiliary construction measures on the expanding excavation construction;The thesis analyzes the proposed programs applied two-dimensional numerical simulation, and then shows the reasonable construction scheme. The author also studies the mechanical behavior during the construction process using three-dimensional numerical simulation.