钱江隧道植筋牛腿的耐火性能试验研究

钱江隧道顶部烟道板与下部车道板均置于采用植筋工艺施工的牛腿上,需通过试验评价牛腿植筋胶在隧道火灾工况下的耐火安全性。试验按1∶1比例制作了两个E型植筋牛腿试件,用千斤顶分别对两个试件植筋牛腿施加与烟道板及车道板相应的垂直荷载,在试验炉内按隧道最大火灾工况热释放功率50 MW规模的RABT标准升温曲线加热,测试了覆盖有防火板的牛腿的变形、牛腿内的钢筋温度、牛腿表面破环情况等。试验结果表明,设计采用的植筋胶、防火板等材料及相应的植筋技术可满足钱江隧道火灾情况下牛腿结构安全使用的要求。

Experimental Research on Fire Resistance Property of Corbel with Planted Rebars in Qianjiang Tunnel

In Qianjiang tunnel, the top flue plate and the lower lane plate are placed on the corbels, which are constructed by the technology of planting reinforcing bars. Thus, to evaluate the refractory safety of the anchorage adhesive under condition of tunnel fire, some experiments are needed. Two corbel specimens with planted E-type rebar and similarity ratio of 1:1 were produced for the tests. The vertical load which was equal to that from the flue board and lane plate was applied to the specimens by using jacks. In the test furnace, heating process was conducted according to the RABT standard temperature curve, corresponding to the largest tunnel fire scale condition with heat release power of 50MW. Deformation, reinforced temperature, and the surface broken ring of the corbels, which were covered by fire-proof plate, were tested. Test results show that the materials such as adhesive, fire-proof plate, and the corresponding reinforcement technology could meet the safety requirements of corbels subjected to fire, and so could guarantee the normal use of corbels in Qianjiang tunnel.