Preventive maintenance on superstructure and pier of aged short-span steel railway structures

Deterioration of existing bridges has become a severe problem and seriously affect the serviceability and durability of railway system in many countries. A preventive maintenance strengthening method using rubber-latex mortar, Glass Fiber Reinforced Polymer (GFRP) plates, lightweight rapid hardening concrete, and reinforcement was introduced this study, which can be used to strengthen the both steel bridge superstructures and bridge piers. In order to confirm the real effects of the present strengthening method, field loading test on a short-span railway bridge and laboratory tests on a steel column were performed. The results on both original and strengthened specimens were summarized and compared. For the railway bridge superstructure, theoretical results were also provided to confirm the strengthening effects. For the steel piers, however, numerical models were built to provide the load carrying capacity of the original pier. The load-displacement curve and load-strain response at key sections were measured in the loading tests and reported in this paper. According to the results, the present renovation method could greatly enhance the rigidity of old steel railway bridge superstructures and the load carrying capacity of existing piers, resulting in the extension of the residual service life of short-span railway bridge superstructures and improvement of seismic behavior of steel piers.