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Location | Doudleby nad Orlicí (district Rychnov nad Kněžnou) Design | STRADA, v.o.s, Hradec Králové, Luboš Skrába a PROMO, spol. s r.o., Praha, Vladimír Jan Co-operation | Pavel Hrůza, Jiří Dohnálek Investor Directorate of Roads and Motorway of CR, Administration Pardubice Technical supervision Karel Levinský Costs | 18,26 miI. Kč General contractor Stavby silnic a železnic, a.s., závod 07 Hradec Králové, site agent Petr Volek Subcontractor | Santech CZ, Rožnov pod Radhoštěm (pressure grouting) Design | 1999 Construction | 1999-2000 Technical characteristics Arch span 36.0 m | Arch rise 7.2 m | Bridge width 12.18 m | Carriageway width 6.33 m | Footways 2 x 1.50 m |
The R.C. superstructure dating from 1932, carrying a 3rd class road across the Divoká 0rlice, consists of two arches with horizontal ties. The lower grillage deck is suspended on vertical suspension rods.
The superstructure is mounted on cast steel bearings, which are fixed on the left-bank abutment and sliding two-roller bearings on the rightbank abutment. The bearings are mounted on well-finished granite blocks. Concrete abutments and adjacent embankment walls are clad with cyclopean masonry.
The bridge was designed in accordance with the regulations in force in the 30s. Since that time, however, the traffic intensity has increased and the impact of the weather as well as other unfavourable factors (particularly the de-icing salts) have combined with neglected maintenance. The bridge started showing defects and ceased
to satisfy the traffic requirements and the safety of pedestrians.
The purpose of the reconstruction was to extend its service life, widen its footways and carriageway and increase the permissible vehicle load. The bridge deck was strengthened with a R.C. composite slab.
The new cantilevers outside the arches accommodated the footways thus making it possible to broaden the carriageway between the arches and improve its waterproofing and drainage. The R.C. structural members were strengthened and repaired. The horizontal tie-rods
of the arches and the vertical bridge deck suspensions were strengthened with prestressed monostrands (steel strands with corrosion-protection surfacing).
The pressure grouting of the arches with epoxy resin of extremely low viscosity was an unusual feature of the reconstruction. This measure was adopted after the denudation of the arches had discovered that the concrete (particularly at the foot of the arches) was interwoven in all directions with minor cracks due probably to the reaction between the aggregate and the cement paste. Another not frequently used method consisted in arch strengthening by a heat-activated steel bandage (bandaging the cross section with transverse steel stripes). The reconstruction did not neglect the visual effect of the bridge, either, and the conservation or renovation of its architectural details.