The thermal-mechanical behavior of tunnel lining segment plays a key role in governing its fire protection design. Existing models are mainly developed for the analysis nonlinear and non-elastic behavior of segment under fire, however the complexity of the model impede their application in engineering. In this study, a multilayer analytical model is proposed to describe the behavior of segment under elevated temperature. The temperature distribution on the cross section can be described by a piecewise function. The contributions of the concrete, and bolt are equivalent to a set of spring in the model. Based on the plane cross-section assumption, the strain distribution on the section is derived. Further, it can lead to the radial and tangential displacements of the tunnel lining segment in general restrictions with 9 integration constants in accordance with geometric relation of displacement and strain. Combination of continuity and equilibrium of forces conditions, equations are established to solve 12 basic unknown parameters. Some special examples with various boundary conditions, such as statically determinate structure, statically indeterminate structure with two hinged ends and fixed ends structure, are analyzed. To verify the feasibility of the model, four points bending tests are conducted with reduced-scale specimens. Test results indicate that this multilayer model well predicts the response of the tunnel lining segment under or after elevated temperature and can be utilized with corresponding design codes in the fire protection design of the tunnel lining segment.

LOKASI: Ruang Koleksi Umum
Rak: 2