Research On The Shield Tunneling Exerts Influences On Nearby Existing Tunnels

Since the twenty-first Century,the rapid development of society promotes the urban construction,the congestion of urban traffic is caused by the process of urbanization,urban subway construction is imminent.However,with the development of urban underground traffic construction,the increasing urban subway lines and the Shield tunnel construction adjacent to one another or crossing some existing tunnel is always occurred.The settlement,crack,and even unstable failure of buildings are usually resulted in the change of stress state of soil mass on the shield tunneling.Research on the shield tunneling exerts influencing on nearby existing tunnels and concluding the regulation is propitious to the normal pressing of shield construction.The engineering of the Hefei Subway Station line 5 crossing line 1 is studied by theoretical research,numerical modeling and the contrasting analysis of monitoring data and simulation to analyze the influence of shield tunneling exerts influencing on nearby existing tunnels.This paper mainly contains as follows:(1)The content and significance of the research are introduced in detail,combined with the engineering example to determine the content and methods of research under the literature research,sum up the law,put forward the problem and analyzed the existing problems which is not resolved.(2)Using the theoretical analysis to summarize the mechanism and law of the influence of shield construction on the surrounding construction and understanding the working mechanism and process of the shield machine.Analyzing their difference under the same construction environment by contrast to analysing the force mechanism of surrounding rock of single cavern and double chamber.(3)The influence of different vertical distance shield construction on existing tunnels is analyzed and compared to obtain the suitable construction distance by defining different construction conditions on the the finite element numerical model based on the actual working conditions.(4)Finding out the similarities and differences between the two rules for the construction of the normal to provide theoretical guidance and the appropriate reference for the similar projects from the comparative analysis in comparision with measured data in the site and the data of the theoretical calculation.