Investigation of the truss spans of railway bridge under operating load

Abstract

The paper presents a description of the structure and its damage and a report on study under the operating load of three truss spans of 42.0 m length each. The spans are located in track no. 2 of two tracks railway Chorzów Batory – Tczew. They crosses the Warta River and its flood terrain in Działoszyn. Following spans are located along track no. 2: one steel beam span of 12.0 m, three truss spans of 42.0 m, one truss span of 32.0 m. The spans were built in 1941/42. They are rivet structures with parabolic shape and girders located under railway. A design of bridge repair and strengthening was prepared. Due to lack of funds the repair works were delayed, but all spans were in bad technical condition. Three the longest ones, which had been examined, had low lateral flexibility. Lateral vibration were noticed, which were consider to be dangerous with a speed limit on the bridge v ≤ 100 km/h and load class of k=+2, αk=1,21 (according to Polish code). The tests result forced the owner to start repair work immediately (mainly to install lateral stiffeners in all spans to eliminate vibrations). It was done by KPRM Kielce company which was already performing repair works at track no. 1.