钢壳混凝土结构火灾高温下温度分布规律研究

Temperature Distribution of a Composite Structure with Steel-shell and Concrete under High Temperature of Fire

钢壳混凝土作为一种新型创造性组合结构,已经运用于工程实际中,但在火灾工况下对其温度传递规律及温度场分布规律的研究较薄弱。文章以深中通道海底沉管隧道为依托,通过ANSYS有限元软件模拟出钢壳混凝土组合结构在火灾工况下温度场的变化规律。对结构在不同高度和受火时间下的温度变化进行详细了分析,得出结论:受火面温度变化情况可分为升温阶段、温度保持阶段和降温阶段;在结构不同的方向上都存在温度达到峰值的时间滞后的效应;相比混凝土,钢材的导热系数更大,温度场易在钢结构周围出现温度场重分布的情况。文章可为钢板式混凝土组合结构的温度传递规律提供借鉴。

As a new composite component,steel-shell concrete is used in engineering project.However,few studies have been conducted on the temperature distribution and transfer pattern for the steel-shell concrete under fire condition.In this paper,the Shenzhen-Zhongshan immersed tunnel is selected as the background.A numerical model of the steel-shell concrete structure is built by using ANSYS to study the change of the temperature in the structure.Temperature distributions at different vertical location and under different firing time are discussed according to the numerical results.It is concluded that the change consists of three stages,including increasing stage,stable stage and decreasing stage.There is a time lag when the temperature reaches the peak in different directions of the structure.Temperature changes faster in steel,compared to the temperature in concrete.In addition,the temperature field around the steel changes.The results achieved in the paper can be references for the design of composite structure with steel-shell and concrete.