The Numerical Simulation Of Subway Ultra-Shallow Holes And Study Of The Related Issues About Construction

With a growing number of cities of china getting into the construction of the subway, the problems in the construction of the ultra-shallow tunnels increased gradually. This thesis select Qu Zhuang station on the rail transit line five and six of Guangzhou metro to study, including the construction of station's ventilation, the construction of station's office and the staggered from top to bottom construction of line five and six. Through the software, we simulate the subway ultra-shallow tunnels numerically, and come up with a reasonable and scientific method of tunnels' construction in order to achieve more economical, reasonable and security objectives.Firstly in this thesis, through the use of large-scale finite element ANSYS software,we establish the plane model of tunnels to simulate the excavation;secondly,we establish three-dimensional model of physical units respectively,including an ultra-shallow and great span tunnel, an ultra-shallow and ultra-high profile tunnel and a two-wire short-range oblique cross proximity tunnel. Through these models we can simulate the process of tunnel excavation relatively accurately and calculate excavation stress and analysis the deformation of tunnel. We analysis the impact in the various steps of the excavation to the tunnel itself and the deformation based on the calculation results, analysis the impact in the various steps of the excavation to the land subsidence, as well as the impact of stress between the steps. At the same time,we combinate with construction site and on-site testing and data analysis,to prove using CRD method in ultra-shallow excavation of large cross tunnels rationalitily and sciencely, and came to sequence in the excavation of the proximity cross- tunnel. Through the depth study of construction technology, the construction of control theory and construction mechanics,we come to the control technology of the construction to the high cross- tunnel in the city.We sum up the control technology of the construction to the high cross-tunnel in the city based on the numerical simulation of subway ultra-shallow tunnels and the field data. These will play a good reference and value in the construction when we encounter the similar problems in the future. And the same time, these can continue to enrich the technology and research in the contraction of ultra-shallow tunnels. We explore theoretically in the complexity of the construction process, the geotechnical, structural behavior and deformation mechanism of the conversion process. We provide an important reference to the scene of constraction monitoring and in the constraction feedback. And the same time,these provide a successful case to the theoretical exploration and research methods of the similar projects in the future.