Research On Fire Performance Of Tunnel Lining Structures

With the development of underground space, a large number of tunnels have been built. As a result, tunnel fires occur frequently. High temperature produced by tunnel fire affects the mechanical properties of reinforcement and concrete and damages the lining structures at different degree. Uneven temperature field causes internal force redistribution of the lining structure, then safety of lining structure is reduced seriously. At the same time, excessive deformation of lining will affect the stability of the surrounding buildings, and even cause its collapse. Therefore, research on fire-resistance behavior of tunnel lining structure become an important subject in fire research field.Fire scenario, a lot of research work on temperature field and lining crack of tunnel have been done at present, but the deformation and mechanical properties of lining under high temperature of fire are seldom involved. Specifications and standards made for the tunnel only regulate fire protection and evacuation problem, which are not perfect and can not meet the practical fire design of lining structures. Fire safety of tunnel lining structure remains to be further research. Based on this, three types of tunnel lining structure (circular lining, curved wall lining, directed wall lining) were theoretically analyzed and numerically simulated. The fire resistance limit, curve of deformation process and internal force of lining were obtained. Detailed work are as following:1. Based on the summary and analysis on the existing research results at home and abroad, suitable calculation model of high temperature materials was determined.2.3D analysis model of tunnel lining using ABAQUS was built and the calculated results of temperature fields and mechanical were verified.3. Fire-resistance of lining under HC curve of reference temperature by using the verified model was analyzed and influencing factors of the lining deformation and inner force variation during heating were investigated.4. After comparing three control standards of fire resistance for lining structure, parametric study of fire resistance for lining was analyzed.5. Fire-resistance of four kinds section of lining was compared, also the different fire response of the four kinds of linings.