天津中医药大学体育馆不连续支承弦支穹顶结构抗火分析

Fire resistance analysis of suspen⁃dome structure with discontinuous support in gymnasium of Tianjin University of Traditional Chinese Medicine

以天津中医药大学体育馆为背景,对大跨度不连续支承弦支穹顶结构进行抗火性能分析。利用高大空间火灾升温公式对结构进行火灾温度场模拟。采用ANSYS软件对不连续支承弦支穹顶结构进行火灾响应分析,得到火灾下该结构变形规律、节点位移及构件预应力损失规律;改变火源位置和火源释热功率,探究火源参数变化对结构抗火性能的影响。结果表明:中心火源工况下,不连续支承弦支穹顶结构变形呈“部分微上凸,局部桁架处下陷明显”;该结构对偏心火灾敏感,偏心火灾下结构最大正、负向位移及环索预应力损失较中心火灾显著增大,且第1、2圈部分环索预应力降为0;局部桁架处压杆及第1、2圈环索为抗火设计重点。火源释热功率越大对不连续支承弦支穹顶结构抗火越不利,但火源释热功率改变对结构火灾响应的影响较小。

Taking the gymnasium of Tianjin University of Traditional Chinese Medicine as the background,the fire resistance performance of large⁃span suspen⁃dome structure with discontinuous support was analyzed.The fire temperature field was simulated by using the formula of fire temperature rise in large space.The ANSYS software was used to analyze the fire response of the suspen⁃dome structure with discontinuous support,and the deformation law,node displacement and prestress loss law of member under fire were obtained.The influence of fire source parameters on the fire resistance performance of the structure was investigated by changing the fire source position and the heat release power of the fire source.The results show that under the condition of central fire source,the deformation of the suspend⁃dome structure with discontinuous support is partly slightly convex,and the local truss is obviously sunken′.Structure is sensitive to eccentric fire,the maximum positive and negative displacements of the structure and the prestress loss of the ring cable under eccentric fire are significantly larger than those under central fire,and the prestress of the first and second ring cables is reduced to zero.The pressure bar at the local truss and the first and second ring cables are the focus of fire resistance design.The larger the heat release power of the fire source is,the more unfavorable the fire resistance of the discontinuously supported suspend⁃dome structure is,but the change of the heat release power of the fire source has little effect on the fire response of the structure.