| With the development of domestic economy, China gets rapid advance in population urbanization, and consequently, it brings out heavier pressure for the urban transportation, so the current surface roads are out of people’s demands, which make the underground traffic is headed. Simultaneously, a new problem that there is overlapping among tunnels built in the same area, so the new tunnel may closely traverse the exiting one, occurs. Without a professional and fully-developed project or standard as a reference, it is hard to design and construct tunnels. As a result, it is of huge significance to grasp the law how the superstructure influences the ground surface settlement during the shielding construction.Contents: Setting the research scope from the South 4th Ring Road to the railroad project around the South Bus Station in Zhengzhou, this paper will minutely analyze and explore the law about settlement, and summarize deformation features and construction experience to pave ways for the future similar projects, with the application of practical engineering cases, based on the datum out of large Finite Element Simulation and monitoring results of actual projects. To make a summary about the effect of superstructure to ground surface settlement, this paper will apply large Finite Element Simulation software ABAQUS to numerical simulation analysis, using the birth-and-death elements in the excavation process, with the adjustment of shielding advancing speed, pressure, and other parameters, accompanied with monitoring results of actual projects.Significance: first, the thesis focuses on digging out the solution of closely traversing betw een tunnels and existed culvert. In consideration of the status quo that underground traffic is r apidly growing, the thesis will give a guidance for the future tunneling projects design and co nstruction, which is pragmatic. Second, it will offer a standard for evaluations of tunneling pr ojects by the conclusion from the actual settlement and deformation, as well as optimization r esults. Third, the application of large Finite Element Simulation and measurement guarantees the accuracy of the conclusion and make it more acceptable. Finally, the thesis will study how to strengthen the area which deforms seriously according to the actual deformation place. |
