钢筋混凝土单向板跨高比对耐火性能的影响

Study on effect of span height ratio on fire resistance of reinforced concrete one-way slab

以某地铁工程车辆段为例,采用ABAQUS有限元分析软件建立钢筋混凝土简支单向板和连续单向板的计算模型,在ISO834标准升温曲线下对钢筋混凝土单向板进行了温度场计算,在此基础上分析跨高比对钢筋混凝土简支单向板和连续单向板耐火性能的影响规律。分析表明:在相同的保护层条件下,简支单向板和连续单向板受火3h的跨中位移均随跨高比增加而降低,但同一跨高比的简支单向板的跨中位移较连续单向板更大,下降的更快。综合考虑经济性与安全性因素,在高温作用下,简支单向板耐火极限跨高比不大于25,连续单向板耐火极限跨高比不大于30,即可满足耐火3h的要求。本文的研究方法可为地下工程钢筋混凝土单向板的耐火设计提供参考。

Taking a subway project as an example,the ABAQUS finite element analysis software was used to establish the calculation model of reinforced concrete simply supported one-way slab and continuous one-way slab.Based on the temperature field calculation of reinforced concrete one-way slab under ISO834 standard temperature rise curve,the effect of span height ratio on the fire resistance of reinforced concrete simple supported one-way slab and continuous one-way slab were analyzed.The results show that under the same cover,the mid span displacement of simply supported one-way slab and continuous one-way slab decreased with the increase of span height ratio,while under the same span height ratio,the mid span displacement of simply supported one-way slab was smaller than that of continuous one-way slab and the simply supported one-way slab had faster descent rate.Considering the economic and safety factors,under the temperature field,the fire resistance limit span height ratio of simply supported one-way slab is not more than 25,and that of continuous one-way slab is not more than 30,which can meet the requirements of fire resistance for 3 hours.The research method of this paper can provide reference for the fire resistance design of reinforced concrete one-way slab in underground engineering.