火灾高温下隧道衬砌管片力学性能试验

Experimental Study on Mechanical Performance of Lining Segments in Fire Accidents

为了获得隧道衬砌管片在火灾高温时的力学性能与响应,对钢筋混凝土及钢纤维混凝土两种管片开展了不同温度-荷载工况下的火灾试验研究.试验中升温曲线采用碳氢(HC)曲线.试验结果表明,在火灾高温作用下,衬砌管片的内力状态发生显著变化,相当于经历了加卸载作用,加重了损伤.初始预加荷载显著影响衬砌管片高温后承载力的大小,初始预加荷载越大,高温后的承载力越小,且钢筋混凝土管片高温后的承载力要大于钢纤维混凝土管片.对于钢筋混凝土管片,最高温度显著影响管片高温承载力的大小,最高温度越高,高温承载力越小;而对于钢纤维混凝土管片,最高温度的影响相对较小.

To investigate the mechanical performance of the tunnel lining segments, a series of fire experiments on the reinforced concrete （RC） and the steel fiber reinforced concrete （SFRC） segments under different load cases were conducted. The HC curve was employed in the experiments. The results indicate that the internal force of the segments varies significantly, which is equal to a loading and unloading action on the segments and aggravate their damages. The initial load presents a great effect on the ultimate load of the segments after high temperature, and the greater the initial load, the smaller the ultimate load. Furthermore, the ultimate load of the RC segments is larger than the ones of the SFRC segments. The maximum temperature has lesser influence on the ultimate load of the SFRC segments under high temperature, while it exerts a significant effect on the RC segments. And the higher the maximum temperature, the smaller the ultimate load of the RC segments under high temperature.