engleski

Preliminary static design of one span stress-ribbon bridge

stress-ribbon bridge, one span, static preliminary design Abstract: Main building components of stress-ribbon bridges are steel cables or steel bands carrying thin concrete, stone or steel plate. Nowadays most deck slabs on stressribbon bridges are made from precast segments. Precast construction eliminates usage of scaffolding and reduces cost of human labor minimizing total construction cost. Small bending rigidity justifies preliminary design of stress-ribbon as cable without bending capability. They can be divided into two main types. First type includes bridges with segments connected on bearing steel cables or bands only in discrete points. Precast elements are put one near another so there is a cross gap in deck slab between neighboring plates causing discontinuity in bending rigidity of stress-ribbon bridge. Cross section area of resulting cable is equal to sum of cross section areas of all cables or bands. Second type includes prestressed concrete stress-ribbon bridges. Precast concrete plates are hanged on bearing cables. Afterwards additional cables are laid through deck slab from one abutment to another. In situ concrete bonds bearing cables with precast concrete plates. Additional cables are tensioned introducing compressive stress in concrete and reducing tensile stresses in bearing cables. Post-tensioning cables are then grouted so composite section consisting of bearing cables, concrete and post-tensioned cables resists loads acting after completion of the bridge. Relevant cross section area of resultant cable is changing depending on construction stage. This paper presents differences in preliminary static design of one span stress-ribbon bridges depending on their type.

stress-ribbon bridge; one span; static preliminary design

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