This study aimed to experimentally analyse the robustness of riveted steel bridges based on truss-type structures and to define practical recommendations for early detection of local failures before they cause progressive structural collapse. Although there are many experimental studies on robustness and progressive collapse on buildings, those on bridges are either theoretical or deal with actual collapses. This paper describes a unique case of a 21 m full-scale bridge span tested under laboratory conditions with an extensive monitoring system, together with an experimental study to evaluate structural behaviour and robustness as damage or failure progressed in its elements. A linear-static finite-element analysis was also included to examine other possible causes not included in the experiment. The results proved the structural redundancy of this type of truss structure based on the joints’ resistance to bending moments and gave rise to a series of practical structural health recommendations to identify early failures and avoid progressive or sudden bridge collapse. The study carried out and the recommendations it produced are now being applied in three similar bridge case studies.

这项研究旨在通过实验分析基于桁架型结构的铆钉钢桥的坚固性，并为在局部破坏引起渐进式结构倒塌之前及早发现局部破坏提出实用建议。尽管有许多关于建筑物的稳健性和渐进性倒塌的实验研究，但是桥梁上的那些研究要么是理论上的，要么是处理实际倒塌的。本文描述了一个独特的案例，该案例是在实验室条件下使用广泛的监控系统对21 m满量程桥梁跨度进行测试的，并进行了一项实验研究，以评估随着构件损坏或破坏的进展而产生的结构行为和坚固性。还包括线性静态有限元分析，以检查实验中未包括的其他可能原因。结果证明了这种类型的桁架结构基于接头抗弯矩的结构冗余性，并提出了一系列实用的结构健康建议，以识别早期失效并避免桥的逐渐或突然坍塌。进行的研究及其提出的建议现在正在三个类似的桥梁案例研究中应用。