Analysis Of The Influences Of The Excavation Of Deep Foundation Pit Of Intercity Railroad On Adjacent Luggage Tunnel And Mrt Tunnel

With the rapid construction and development of urban modernization, a new type of traffic travel mode has emerged, it is intercity railroad. Intercity railroad can not only improve the image of a city, but also become a good solution to the people across the city travel, it can reduce traffic pressure in the city and improve the city traffic condition. But when the deep foundation pit of intercity railroad is in the process of excavation, we can not ignore the problem that the excavation brings the influence to the surrounding environment in the engineering construction. The interference of the tunnels caused by the construction of deep foundation pit can be showed in two aspects, they are displacement and stress. With the excavation depth is larger, the soil unloads more, it will make the surrounding soil loss different degrees of stress. It also can destroy the structure of luggage tunnel and MRT tunnel. At the same time, the normal use of the two tunnel will be affect. In this paper, Zhengzhou Airport-Xuchang intercity railroad is considered as the engineering background, by using the ABAQUS finite element software, to establish finite element models about the interaction among the deep foundation pit, soil and tunnels. And to analysis the displacement influences of the excavation of deep foundation pit of intercity railroad on adjacent MRT tunnel and luggage tunnel. Related work and the main contents and results of this paper are as follows:(1) To summarize analysis methods and technical measures which are adopted by scholars at home and abroad to study the influence of foundation pit excavation on the adjacent tunnel. it provides reference and theoretical basis to the next technology research analysis. To classify the engineering examples that included in the literature and highlights the particularity of this paper based on engineering background in the research process.(2) To collect the on-site monitoring data and to analysis the displacement influences of the excavation of deep foundation pit of intercity railroad on the slope, and to do the monitoring analysis to the vertical displacement of luggage tunnel that caused by the excavation of deep foundation pit of intercity railroad. Then to conclude the control measures that can ensure the construction safety in the process of foundation pit excavation.(3) Using ABAQUS finite element software to establish three-dimensional finite element models and simulate the working conditions. The constitutive model of soil is Mohr-Coulomb model. To get a change rule by analyzing the horizontal and displacement change of the MRT tunnel, luggage tunnel, soil and underground continuous wall during the excavation of deep foundation pit of intercity railroad. And to compare the vertical direction change of luggage tunnel between the model analysis and measured changes.(4) To establish some numerical models and to analysis the deformation influence of foundation pit on the tunnels and get relevant rules. The influence factors conclude different excavation depth, the change of horizontal spacing between foundation pit and tunnels, soil conditions and presence of horizontal support conditions.