Splavarska Brv (Rafting Footbridge)

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• 作者：Gregor Gruden^a ; Marko Hozjan^a ; ^{marko.hozjan@imk.si" class="auth_mail" title="E-mail the corresponding author} ; Alojz Rovan^b ; Denis Rovan^b ; Gregor Planin&scaron ; ek^b
• 关键词：Footbridge ; composite steel-concrete structure ; trapezoidal steel cross-section and concrete slab
• 刊名：Procedia Engineering
• 出版年：2016
• 出版时间：2016
• 年：2016
• 卷：156
• 期：Complete
• 页码：124-131
• 全文大小：793 K

文摘

“Splavarska brv” (Rafting Footbridge) spans over the Savinja River in Celje, Slovenia. It crosses a local road and descends spirally into the city park. It was part of a flood control project in the Savinja River basin. The main span is 74 m long; the overall length of the footbridge is 147.5 m. The total weight of the steel structure is approximately 160 t. The maximum height of the cross-section is 1490mm.

Steel segments were fabricated in a workshop and welded on site (on the old footbridge, which stood near the new footbridge). After welding the 87.5 m long and 112 t heavy steel structure was lifted and mounted with two mobile cranes (one on each bank of the river). The footbridge is fixed to a piled concrete block on one side of the river and simply supported on the other side, where longitudinally moveable compression and tensile supports act as a couple of forces (reactions). Special instructions were prepared for the contractor to introduce proper moments into the fixed support.

The footbridge was designed as a composite steel-concrete structure. Trapezoidal cross-section of the main span was designed as a steel box girder with variable height, inclined web and a thin reinforced concrete slab. Steel plates were made as orthotropic plates with longitudinal stiffeners. Where heights of the trapezoidal cross-section are low (minimum 0.53 m), orthotropic plates are also used as “lost formwork” for the concrete slab. The thickness of steel plates ranges from 10mm in middle span to 60mm near bearings. The steel structure itself has a critical first natural frequency. The addition of the concrete slab ensures acceptable behavior of the bridge construction, which does not come in resonance any more. Reinforcement with concrete slab adds additional resistance and stiffness to the load bearing structure.