|
The Nordhordland Bridge ((ノルウェー語:Nordhordlandsbrua)) is a combined cable-stayed and pontoon bridge which crosses Salhusfjorden between Klauvaneset and Flatøy in Hordaland, Norway. It is long, of which the pontoon section is long. The cable-stayed section consists of a single tall H-pylon which has a length of and a main span of . This allows for a clearance of . The floating section is a steel box girder bridge with ten pontoons, which because of the fjord's depth are not laterally anchored. The roadway sits on an orthotropic deck. The pontoons and the cable-stayed bridge are built in concrete, with the main span being supported with 48 cables. The fjord end of the main span is supported by a deep foundation, where the two bridges meet. From there and for , the roadwall has a 5.7 percent gradient on a viaduct anchored to the pontoon bridge. The bridge carries two lanes of European Route E39, also called the Coastal Highway, and one pedestrian and bicycle path, and connects the district of Nordhordland to Bergen. Plans for a bridge had existed since the 1960s, and after the decision to construct the bridge was passed by the Parliament of Norway in 1989, construction started in 1991. Total costs, including auxiliary roads, was NOK 910 million. Part of the contract payment was subject to a court case which the contractors lost. The bridge opened on 22 September 1994, and remained a toll road until 31 December 2005. In 2014, it had an average daily traffic of 16,580 vehicles. There are plans to reinstate a toll on the bridge from 2013 to finance other road projects. The bridge is the second-longest in Norway, and the second pontoon bridge in Norway. ==Specifications== The bridge consists of three sections, a cable-stayed bridge, a pontoon bridge and a viaduct which connects the two. The cable-stayed bridge consists of a tall H-pylon with a foundation at Klauvaneset on the mainland of Bergen. It supports a main span, with the other end being fixed in a foundation below mean sea level, which is anchored in the ridge Klauvaskallen. The whole cable-stayed bridge is long, with a long viaduct, supported by six pairs of pillars. The cable-stayed bridge allows for a sailing channel which is tall and wide. The main span is built in lightweight LC55 concrete, while the viaduct and pylon is built with conventional C45 concrete. Inside the pylons is a hollow area. The bridge has 48 cables, 12 on each side of the pylon on each side of the roadway. The distance between the cables is on the main span, and on the viaduct. Combined, the cables are long; each cable consists of 67 to 230 twined cables, each with a diameter. The cables have a weight of between each, and they have a capacity of between . They can be tightened at the connection with the roadwall.〔 The floating section consists of a steel box girder placed on top of ten floating pontoons. The pontoon section is anchored only at both ends, on the underwater foundation at Kauvaskallen and on Flatøy. It is fastened using flexible plate connections fastened by bolts and cables under tension. These are flexible around the horizontal axis at right angles towards the axis of the bridge, allowing for deformation caused by the tide. The fastening on Flatøy consists of a massive concrete block long and tall which was poured into a blast-out foundation pit in bedrock. Vertical pretension rock anchors have also been installed, with 12 at Klauvaskallen and 14 at Flatøy, giving of support, although they were only built to increase the safety factor.〔 There are ten lightweight concrete pontoons, with spans between them. The pontoons are between in height. The draught varies between . Each pontoon consists of nine watertight cells which are partially filled with ballast for trim. The cells are dimensioned so two adjacent cells can fill with water without endangering the bridge.〔 The roadway lies on top of an orthotropic deck on a steel box girder, which is wide, tall and long. The steel box girder weighs , of which is high-strength low-alloy steel. The girder has an octagonal shape and is made with thick steel plates. They are longitudinally stiffened by trapezoidal stiffeners supported by cross frames at most every . Two full bulkheads have been used for every pontoon pilaster, made from welded steel plates thick. External brackets built into the bulkheads transfer the support forces to the pontoons. The girder was built in sections of 21, 36, and 42 meters (69, 118, and 138 ft), which were subsequently welded together into 11 modules with a skew angle of 1.2 to 1.3 degrees. The girder has a constant cross-section throughout the length, except at the anchoring points to the pontoons. The section from the land anchoring to the first pontoon is subject to the most stress, and is made with steel with a higher yield point. The inside of the girder has two dehumidifiers which ensure that it does not rust. The clearance under the girder is .〔 The two bridges are connected with a long steel viaduct, which runs on top of the floating bridge, bringing the road from above mean sea level. The viaduct weighs and has a gradient of 5.7 degrees. It consists of spans between , with the roadway also built as an orthotropic deck with thick plates. Overall, the construction of the bridge used of concrete, of which in the pontoons. The bridge was coated with of paint.〔 The bridge is monitored by 132 sensors, including sensors on hatches to the pontoons, on doors to the steel box girder, for corrosion, strain gauges on the girder and on flexible elements, and weather information. On the cable-stayed section, the bridge is marked with navigation lights, as well as the center of the sailing area having a racon.〔 The bridge is the second-longest bridge in Norway, behind the Drammen Bridge. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nordhordland Bridge」の詳細全文を読む スポンサード リンク
|