Roadway tunnels often include a reinforced concrete drop ceiling that is hung from the liner to create a plenum that facilitates ventilation and houses utilities. Drop ceiling panels are lightweight compared with the much thicker tunnel liner and can experience significant damage from a fire on the roadway below. This paper examines the flexural response of drop ceiling panels in two representative tunnels to standard fire curves as well as several realistic fires due to vehicular accidents. Standard fire demands as per the Rijkswaterstaat and ASTM E1529 fire curves are uniformly applied to the ceiling panels, and heat exposure contours for typical vehicle fires with heat release rates of 30, 100, and 200 MW are generated from the software CFAST. The finite element analysis software SAFIR is used to evaluate the thermo-mechanical behavior of the ceiling panels when subjected to various thermal demands from the fire below. The analysis results indicate that drop ceiling panels are highly vulnerable to fire-induced damage and potential collapse both during a fire’s active heating phase (from simultaneous loss of capacity and restraint of thermal expansion) and during the subsequent cooling period (from tension that develops when the permanently deformed panel thermally retracts). The potential for fire-induced damage or collapse of the drop ceiling panels can be mitigated by reducing the fire hazard, removing the drop ceiling, or enhancing the fire resistance of the panels via the application of passive protection or structural hardening.

巷道隧道通常包括一个钢筋混凝土吊顶，它悬挂在衬里上，以创建一个促进通风和容纳公用设施的通风室。与更厚的隧道衬砌相比，吊顶板重量轻，并且可能会因下方道路上的火灾而受到严重损坏。本文研究了两个具有代表性的隧道中吊顶板对标准火灾曲线的弯曲响应以及由于车辆事故引起的几种实际火灾。根据 Rijkswaterstaat 和 ASTM E1529 火灾曲线的标准火灾要求均匀应用于天花板，并且热释放率分别为 30、100 和 200 MW 的典型车辆火灾的热暴露轮廓由 CFAST 软件生成。有限元分析软件 SAFIR 用于评估天花板在承受来自下方火灾的各种热需求时的热机械性能。分析结果表明，吊顶板在火灾的主动加热阶段（由于同时丧失容量和抑制热膨胀）和随后的冷却阶段（由于在火灾时产生的张力）都极易受到火灾引起的损坏和潜在倒塌的影响。永久变形的面板会热缩回）。可以通过减少火灾危险、移除吊顶或通过应用被动保护或结构硬化来提高吊顶的耐火性来减轻吊顶板因火灾引起的损坏或倒塌的可能性。