Influence Of Shield Tunnel Excavation On Ground Surface And Overlying Building Foundation

At present,many large and medium-sized city are facing serious problems of transportation,transportation space has been unable to meet the needs of people in the city,the subway has become an important means of transportation.Many large and medium-sized city in China are active in the development and utilization of city underground space,ground transportation will be enormous pressure trying to disperse into the underground space,so as to alleviate the adverse effects on the transportation pressure and environmental pollution of the city.With the continuous development of underground space,Metro construction technology is also constantly innovation,in recent years,the most widely used tunnel construction method is shield method.With the continuous development of subway construction,underground subway lines are becoming more and more intensive.Metro construction has many advantages,but when facing the underground rail line staggered and complex built underground structures,especially to pay more attention to the influence of shield construction on adjacent underground structures.Therefore,the study on the influence of shield construction on the deformation of adjacent structures has become a major concern of experts and scholars at home and abroad.In this paper,combined with the Shenyang Metro Shield Project Hunnan Avenue station of Metro Line 10,the influence of shield construction process settlement tunnel deformation effect displacement and assumptions on above the tunnel surface beneath the building based on the foundation overburden deformation of structures and the analysis of the law.The main analysis in the shield construction process,through the process of dynamic simulation of tunnel excavation of building foundation in different distance and under the same conditions,influence on the deformation of foundation displacement of different types of tunnel excavation.The main research work of this paper is as follows:(1)Summarized the research on the deformation of the adjacent building foundation during the shield construction by experts and scholars at home and abroad,and analyzed the research status of this topic at home and abroad.This paper introduces the development history of shield construction technology,the classification,type selection and structure of shield machine,and the construction principle and construction process of shield machine.(2)This article mainly uses the formula calculation and the numerical simulation analysis two methods to shield the construction and the overlying foundation to carry on the research.Using MIDAS GTS geotechnical engineering finite element analysis of shield tunnel soil created 3D model,deformation stages of surface subsidence and the foundation of the analysis.At the same time,the influence of different soil properties,soil thickness and tunnel lining material on the ground settlement is analyzed.(3)In the same tunnel surrounding rock parameters,two different kinds of the basic form of the raft foundation and independent foundation,according to the Foundation Center and the tunnel horizontal offset distance were set up six different types of conditions,characteristics of comparative analysis summed up the basic deformation.