摘要
为了研究火灾下隧道衬砌的安全性,首先采用火灾模拟软件FDS4.0模拟不同规模的火灾:通过许多小的长方体堆砌建立隧道的实体模型,并采用FDS4.0中的多重网格技术(Multiple Meshes)进行网格划分;然后结合仿真得到横断面的温度场与相应温度下的材料参数,应用荷载-结构模式(即直刚法)对二次衬砌的安全性进行评估。结果表明:小规模火灾下(<20 MW),衬砌的安全性能够得到满足,在较大火灾规模下(≥20 MW),拱顶的安全性得不到满足,而其余部位的安全性满足要求;随着火灾规模的增大,衬砌安全系数逐渐降低,拱顶的安全系数降低梯度最大。最后,对衬砌的耐火措施提出了一些建议。
FDS4. 0 （Fire Dynamic Simulator） is firstly used to simulate fire with different heat release rate （5MW, 20MW and 50MW） under no ventilation. Small cuboids are heaped to build curve tunnel, and multiple meshes technology is used to establish grids. Then, based on the transverse distribution of temperature derived from fire simulation and material properties from relative experiments, lining safety is assessed by load-structure model, that is direct stiffness method. Results show： under small fire scales, lining safety can meet requirement, but under large fire scales, only lining safety of crown can not meet requirement; with fire scale increasing, safety coefficient decreases, especially in crown. Some suggestions on fire prevention of lining are finally given.
出处
《灾害学》
CSCD
2008年第2期96-100,共5页
Journal of Catastrophology
基金
西部交通科技建设项目(20033179802)
关键词
隧道火灾
隧道衬砌
安全评估
直刚法
tunnel fire
tunnel lining
safety assessment
direct stiffness method
