|Novosibirsk||Ob River Crossing – Bugrinsky Bridge in Novosibirsk|
|Sochi.||Back-up of Kurortny Prospect, 3 stage|
St. Petersburg (reconstruction)
Design, Detail Design Development
Project period: 2006 – 2012
General Designer: Institute Stroyproekt JSC
Client: Committee for Development of the City Transport Infrastructure
Main parameters of the bridge:
- Total length of the bridge between the embankment walls: 260.1 m.
- Width of the bridge between the hand railings axes: 27.72 m.
- Number of lanes: 6
- A five-span bridge with a central bascule span and a span layout (38.6+47.1) + 9.2 + 58.6 + 9.2 + (47.1+38.6) m
- Navigation clearance in closed (and open) position: 22.0 * 6.3 (30.00) m
- Years of construction: 1912–1916
- Design Codes dated 1907
- Deck material: cast steel (St3)
Reconstruction of Dvortsovy Bridge under Stroyproekt design should have been carried out in 2007–2008 but for some reasons the plans were changed. Instead, implementation of the project was postponed and a number of measures developed by Stroyproekt have been carried out to prolong the service life of the bascule span by several years.
After a while, reconstruction of Dvortsovy Bridge became urgent again. The bridge complex survey carried out by the specialists of Stroyproekt proved that some elements of Dvortsovy Bridge were in an extremely poor condition while the counterweights and suspension units of counterweight blocks were about to fail.
Dvortsovy Bridge has withstood for 90 years without any overhaul. The bridge survey revealed numerous defects such as an extensive corrosion of the deck steel in the support areas, failure of the water discharge system, damaged waterproofing and painting. Besides, the abutments have tilted towards the river which resulted in displacement of bearings. In addition, damages of the pier granite masonry and joints have been observed.
Wear of draw mechanisms became a critical problem; our experts found out that the pivot bearings, blocking and unblocking mechanisms were significantly damaged. The pier recesses of the draw span were repeatedly flooded due to the poor waterproofing. Blocking of the draw span could happen at any moment, which would disrupt the navigation. Therefore, the draw span mechanisms and equipment needed urgent replacement.
The engineers of Stroyproekt were assigned a challenging task to develop a reconstruction project for Dvortsovy Bridge that would meet up-to-date service requirements and at the same time preserve to the utmost all historical elements of the bridge which is one of cultural heritage sites of St. Petersburg. In particular, the hand railings of Dvortsovy Bridge, torchers, granite facing, steel structures and the draw span are of great historical value. Besides, the bridge appearance, its height and outline dimensions had to be maintained.
According to the design, reconstruction included replacement of the draw span equipment and counterweights, strengthening of the existing decks steelworks, replacement of the bridge floor, reconstruction of the junctions between the abutments and the embankments, and restoration of granite facing, torches and hand railings. A hydraulic mechanism for the draw span has replaced the old electro-mechanical drive system.
For reconstruction, 1500 tons of new steel works have been used. The design also provided for application of state-of-the-art materials, for example the recesses of the draw span piers have been filled with nanoconcrete, which is 25% lighter than conventional one.
Reconstruction of Dvortsovy Bridge started in October 2012.
Traffic management during reconstruction period
Traffic management during reconstruction was an acute problem. It had been originally planned that some traffic would be diverted to a new Novoadmiralteysky Bridge but its construction had been postponed.
The Contractor (Pylon JSC) and Stroyproekt have managed to find a solution that allowed for partial traffic on the bridge during its reconstruction.
Just before start of the project, it turned out that in parallel construction of Sportivnaya-2 metro station would be carried out implying traffic limitations on another bridge in the area – Tuchkov Bridge. This could result in severe traffic congestions. Stroyproekt Transport Planning Department have modelled over 20 alternatives of possible traffic diagrams. This study allowed changing the existed traffic scheme to ensure optimal traffic in the given circumstances.
On 19 October 2013, the renovated bridge was opened.
After reconstruction, the expected bridge service life will be 70 - 100 years. The reconstruction cost is RUR 2.9 billion.