Research Of The Deformation Joint Set In Tunnel Lining Structure

In recent years,with the rapid development of urban rail transit system in China,the status of tunnel structure in urban development is more and more prominent.Both the long tunnel and underground railway structure have accumulated rich construction ability and experience,but a large number of tunnel structures in operation stage have appeared some phenomena,such as side wall deformation,crack,masonry falling off and leakage,etc.Some even seriously interfere with the normal use of railway lines,it is proved that this situation is more obvious when there are no deformed joints.Especially in different regions of the surrounding rock geological changes,large temperature difference inside and outside the tunnel will seriously affect the mechanical performance requirements of the structure.But eye In the research of tunnel structure,most of them focus on the simulation analysis of tunnel excavation construction process or the analysis of waterproof leakage of deformed joints,but lack of research on structural design of tunnel deformed joints.As an important detail structure of tunnel,deformation joint plays an important role in the mechanical performance of the structure.Based on the above problems,his paper mainly studies the influence of temperature factor and geological factors on tunnel structure.A number of studies were carried out on the following issues.Firstly,this paper introduces the present situation of tunnel structure research and application at home and abroad,and puts forward the purpose and significance of this study.The classification of surrounding rock,the temperature field of tunnel and the setting of deformation joint are introduced,and the classification of surrounding rock and the study of mechanical characteristics are discussed in detail.According to the actual situation of the project,the classification of surrounding rock and the division of materials are carried out,and the thermal analysis unit is reasonably selected according to the different heat transfer modes of the tunnel,and the steady-state temperature field under different temperature difference is established after selecting the thermal physical parameters.According to the uneven settlement of surrounding rock and the variation of temperature difference,the tunnel deformation joint is set up reasonably.The mechanism of deformation joint setting and the requirement of safety and reliability are explored,and the tunnel is established by ANSYS finite element software.The three-dimensional load-structure model of the tunnel is used to simulate the tunnel deformation joint under different surrounding rock grade and different temperature difference.The stress characteristics and safety reliability of the two working conditions are compared,and the displacement and stress values of the joints at the supporting arch are extracted for curve simulation analysis,and the mechanical properties of the structure with or without deformed joints are discussed.The rationality of deformation joints in tunnel structure is proved by numerical simulation of deformation joints in different surrounding rock classes and different temperature differences.The basic law of the influence of tunnel deformation joint on the stress of tunnel structure is summarized and the relationship between the existence of deformation joint and the safety and reliability of the structure is discussed in order to provide a valuable reference for engineering practice.