Experimental and numerical study on failure mechanism of steel-concrete composite bridge girders under fuel fire exposure
Experimental and numerical study on failure mechanism of steel-concrete composite bridge girders under fuel fire exposure
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燃料火灾下钢-混凝土组合桥梁破坏机理试验与数值研究
DOI：
10.1016/j.engstruct.2021.113230
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发表时间：
2021-11
影响因子：
5.5
通讯作者：
Kodur Venkatesh
中科院分区：
文献类型：
--
作者：
Song Chaojie;Zhang Gang;Li Xuyang;Kodur Venkatesh
本文对典型的钢-混凝土组合梁在局部燃料火灾作用下的破坏机理进行了试验研究和数值研究。在燃油(柴油和液化石油气)、火灾暴露和结构荷载的共同作用下，对3种不同梁型的缩尺桥梁进行了试验。测量了火灾作用下组合梁的相关温度响应和结构响应，并用其验证了建立的预测组合梁火灾行为的数值模型。进一步利用该模型进行了参数研究，以确定火灾和荷载情景、腹板长细比和高跨比对火灾暴露的组合梁破坏机理的影响。燃料火灾试验结果表明，典型钢-混凝土组合梁的跨中挠度从燃料火灾暴露初期开始迅速增大。所有这些梁都被观察到由于大挠度和抗弯能力的显著退化而失效。封闭截面的桥梁梁具有一侧限温的优点，因此具有良好的固有耐火性能。进一步的参数分析表明，随着火灾烈度和荷载水平的增加，组合梁的破坏状态从过度挠度向强度极限转变。高跨比越大的组合梁，其跨中挠度向燃料火灾暴露末期的增长速度越快，不能再承受荷载。当这些梁达到破坏极限状态时，跨中挠度比L/20小得多。腹板长细较大的组合梁抗剪能力退化速度较快，这会导致腹板在破坏时发生明显的屈曲。
This paper presents an experimental together with numerical study for investigating failure mechanism of typical steel–concrete composite bridge girders under localized fuel fire exposure. Three scaled bridge girders with different girder geometries were tested under combined effects of fuel (diesel oil and liquefied petroleum gas) fire exposure and structural load. Relevant thermal and structural responses in fire exposed composite bridge girders were measured, and then used to validate a numerical model developed to predict fire behaviour of composite bridge girders. The model is further utilized to perform parametric studies to determine effect of fire and load scenario, web slenderness, and height-span ratio on failure mechanism of fire exposed composite bridge girders. Results from fuel fire tests indicate that mid-span deflection in typical steel–concrete composite bridge girders increased rapidly from initial stage of fuel fire exposure. All these girders were observed to fail by large deflection and significant degradation in flexural capacity. The bridge girder with closed section offered an advantage limiting heating on one side, and thus has superior inherent fire resistance. Further, parametric studies demonstrate that failure state of composite bridge girders shifts from excessive deflection to strength limit with increase of fire severity and load level. The composite bridge girders with larger height-span ratio manifest a more rapid increase in mid-span deflection towards final stage of fuel fire exposure and thereafter could no longer sustain the applied load. When these bridge girders reach failure limit state, mid-span deflections are much smaller than L/20. Shear capacity degrades at a faster pace in composite bridge girders with higher web slenderness, and this can lead to significant web buckling at failure time.
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DOI：
10.1016/j.advengsoft.2018.11.003
发表时间：
2019-02
期刊：
Adv. Eng. Softw.
影响因子：
--
作者：
J. Alos-Moya;I. Payá-Zaforteza;A. Hospitaler;E. Loma-Ossorio
通讯作者：
J. Alos-Moya;I. Payá-Zaforteza;A. Hospitaler;E. Loma-Ossorio
影响因子：
4.1
作者：
Gang Zhang;V. Kodur;Chaojie Song;Shuanhai He;Qiao Huang
通讯作者：
Gang Zhang;V. Kodur;Chaojie Song;Shuanhai He;Qiao Huang
影响因子：
4.7
作者：
G. Peris-Sayol;I. Payá-Zaforteza;J. Alos-Moya;A. Hospitaler
通讯作者：
G. Peris-Sayol;I. Payá-Zaforteza;J. Alos-Moya;A. Hospitaler
影响因子：
4.1
作者：
I. Payá-Zaforteza;M. Garlock
通讯作者：
I. Payá-Zaforteza;M. Garlock
影响因子：
3.1
作者：
Yong Du;Yafang Sun;Jian Jiang;Guoqiang Li
通讯作者：
Yong Du;Yafang Sun;Jian Jiang;Guoqiang Li