Bridging Europe10 July 2020
Bridges of various sizes have been installed, transported or dismantled around Europe in recent months, Sotiris Kanaris reports.
The construction or dismantling of bridges requires extensive planning in terms of the lifting operation and the transportation of bridge sections.
Among the parameters taken into account when choosing the lifting equipment are: safety; the weight and dimensions of the sections; the height at which they are to be installed; the space available at the job site.
For recent bridge projects in Europe, a wide range of lifting equipment has been deployed including: all terrains, crawler cranes, tower cranes, stand jack and jack-up systems.
For the installation of a new pedestrian bridge at Vienna’s International airport in Austria, Prangl opted for its largest all terrain.
The bridge spans 92m and connects car park 3 to the new office park 4. This new structure has Austria’s largest LED wall with a surface area of around 180sqm installed.
The Prangl experts were involved in the planning process right from the start.
Moving the steel elements was not entirely without risk due to the narrow space and various built-in parts at the installation location.
The hardstanding also had to be chosen very carefully. The specification was to lift both steel structures from one location.
As the Austrian railway company ÖBB have their underground City Airport Train service nearby, there was not much ground that could handle the load.
Prangl decided that the most economical solution was to deploy its largest all terrain crane, a Demag AC1000, which has a maximum capacity of 1,000t and 50m-long main boom. One particular feature of this crane is that the main boom can be upgraded to a telescopic length of 100m.
Two nights were originally planned for the two lifting procedures. However, due to adverse weather conditions, the job had to be completed in one night. All traffic was stopped or diverted between 23:00 and 05:00.
Prangl’s team began to move the first bridge element (33.9m long and 47.6t in weight) right on time at 23:00. The 1,000-tonner had to work with a working radius of 34.3m. The second bridge part, weighing 79.7t and 62.1m-long, was lifted precisely into place at around 03:00.
All terrains were also used to dismantle an old bridge at risk of collapse in Austria. Mayer Autokran-Vermietungs used its two 400t Tadano ATF 400G-6s for the job in the city of Dornbirn.
The bridge in danger of collapsing, measured 44m long and weighed 58t, was suspended above a gorge about 80m deep.
Approximately 10,000 cubic metres of rock had been broken off under the bridge, and the time had come to dismantle the bridge as quickly as possible.
The equipment used had to be able to reach the site quickly and carry enough additional equipment with it, without exceeding the legally permitted 12t axle load. It also had to flexibly support counterweights on site and be ready for action after a short set-up time.
“A special quality of the ATF 400G-6 comes in the form of its ten counterweight variants. With a maximum of 11t per unit, the counterweights can be combined particularly flexibly, which represents an enormous advantage—especially on projects such as this. This enabled us to react very quickly to changing conditions on site,” said managing director at Mayer Autokran- Vermietungs, Erich Mayer.
The challenges began even before the actual deployment, as the access road proved to be extremely narrow. More challenges arose on site, as there was limited space and huge gradients where the cranes had to be set up.
The AML crane control system of the ATF 400G-6, allows it to fully utilise the load potential at any angle of rotation, even with asymmetrical outriggers. Both 400-tonners carried out the job with a counterweight of 138t each.
Due to the inclined position of the bridge and its weight, the cranes were tasked with securing the loads and preventing the bridge from swinging. This was the basis for screwing on and removing the bridge sections step by step. After about 1.5 days, the operation at the site was complete—but perhaps only temporarily, as it is not yet clear how the planned renovation will continue.
Not only mobile cranes are used for bridge projects, some projects’ requirements can only be met by tower cranes.
Zoomlion tower cranes are being used for the construction of the Pelješac Bridge, which will connect the southernmost part of the country and Dubrovnik to the rest of mainland Croatia.
With an overall length of 2,440m, the Pelješac Bridge is designed as a six-tower single- cable-stayed bridge. It will have 13 spans in total and a maximum span of 285m.
The project is estimated to cost around €420m, with EU funds covering 85% (€357m) of the construction costs. A consortium of Chinese enterprises led by the China Road and Bridge Corporation won the bidding for the bridge and phase I of its connecting line project. It is the first large-scale infrastructure project to be won by Chinese enterprises in the EU with the support of EU funds, says Zoomlion. According to the requirements of the project, the cranes used for the construction of the bridge should pass the CE certification of the European Union and the safety inspection of a local third party.
The project is located in Mali Ston Bay in the Adriatic Sea. There are often force 6–8 winds in the area, with maximum winds of up to force 13. In addition, offshore operations involve serious corrosion. These challenges have raised high requirements for wind resistance, corrosion resistance and equipment stability.
A Zoomlion T7020-12H(IL) tower crane and construction hoist has been installed on each of the six piers of the Pelješac Bridge. The tower cranes are hoisting reinforcing steel bars and formworks.
The average operating height of the tower cranes is 100m. This model has a maximum jib length of 70m and maximum capacity of 12t. Taking into account the high winds at sea, Zoomlion designed an embedded bolt foundation and two non-standard attached wall frames for each tower crane according to the position of the pier relative to the tower crane.
Alternative lifting equipment such as strand jack systems and jack-up systems are also popular for bridge construction.
Fagioli used two crawler cranes and strand jack systems for the demolition of the Morandi Bridge and the construction of the new bridge in Genoa.
The last span of the deck for the new bridge, designed by famous architect Renzo Piano, was installed at the end of April.
The new bridge is replacing the Morandi bridge, part of which collapsed in August 2018, killing 43 people. Consortium company Pergenova was established by Fincantieri and Salini Impregilo, to design and build the Polcevera viaduct on Italy's A10 motorway. Fagioli was contracted by Pergenova for the transportation and lifting of the old and new bridge sections.
For the demolition of the Morandi bridge, Fagioli supplied strand jack system, two crawler cranes and Self-Propelled Modular Transporters (SPMTs) for the dismantling and lowering of old bridge sections.
The new bridge has a continuous steel deck measuring 1,067m in total with 19 spans. When the construction started, Fagioli moved by barge and by modular trailers a total of 237 sections, weighing from 56t to 89t, which were used to build the viaduct. The transportation of these sections took a total of 60 nights.
The three main decks are 100m long and weigh up to 2,000t. Fagioli transported them using SPMTs and installed them at a height of 40m using a strand jack system. For smaller deck sections, the crawler cranes with capacities up to 1,200t were used.
An alternative lifting system was also used for a UK bridge project. An eight-point Enerpac jack-up system enabled logistics and heavy lift specialist Osprey Group to complete a 1,400t bridge deck installation with a single movement.
The 74m long x 16m wide bridge deck replaced an existing bridge over a dual carriageway. Using the JS-250 jack-up systems allowed the bridge deck to be built next to the highway and transported on SPMTs to the installation site. The jack-up units were delivered smoothly to the deck construction site by flat-bed trucks, which meant no need for specialist transport.
Installation of the bridge was completed over a weekend. With four JS-250 jack-ups at either end, the bridge deck was lifted and then transported 500m to the bridge abutments on the dual carriageway by SPMTs. Accurate positioning of the bridge deck to 6.8m at its highest inclined point with the Enerpac jack-ups was critical.
Once in position, SPMTs were used to provide the final height positioning.
Ryan Ebanks, project engineer at Osprey Group. “Given the size of the bridge deck in this instance, and the need to incline it by 1.5m, the Enerpac jack-up was a perfect choice. Without them, we might have had to use multiple cranes.”
At the end of May, Mammoet used eight towers of Mega Jack 800 for the installation of a new steel arch bridge at the Port of Rotterdam, the Netherlands.
The new railway bridge spans the Thomassentunnel and the A15 and N15 motorways. Its steel structure alone weighs 4,100t, is 269m long, 13.7m wide and 28m tall. It was built by Hollandia, based in Krimpen aan den Ijssel, the Netherlands.
For the transportation of the bridge Mammoet used 184 axle line SPMTs. For the lifting operation, the company opted for eight of its own Mega Jack 800 jacking systems, each tower has a capacity of 800t.
The new bridge forms a key link in the Theemswegtracé, a new branch of the port railway line. It is the second one to be installed for the project, which also includes a 4km stretch of concrete viaduct, commissioned by the Port of Rotterdam Authority to SaVe. SaVe is a construction consortium made up of BESIX, Dura Vermeer, Mobilis, Hollandia and Iemants.
In early May, heavy-load logistics company Schmidbauer transported a 1,500t, 130m-long bridge in Germany.
Schmidbauer had to realise the transfer from the pre-assembly site in a field near the A8 motorway to the point of installation where it had to be positioned and set down precisely on four piers. Although the distance from the pre-assembly area to the jobsite was only around 150m, the construction management team had calculated that a two-hour drive was required.
For this job, Schmidbauer opted for SPMT axle lines from Scheuerle. A total of 56 axle lines were required in order to distribute the load of the bridge, support beams and sub-structure as well as SPMT modules totalling 2,000t over the 224 wheels so that the load on the ground was kept to an absolute minimum.
In order to guarantee safe transportation of the bridge, Schmidbauer formed four individual transport platforms using the individual SPMT modules, each of 14 axle lines, which were then driven in a loose coupling mode formation. Four power packs from Scheuerle with a total output of around 2,000hp provided the drive.
“The biggest challenge on route was to drive absolutely synchronously with the four SPMT transport platforms in a loose coupling mode,” said Stefan Schmidbauer, managing director of the eponymous company. As it happened, the centre distance between the platforms was 80m whilst the width between the transport modules measured seven metres. The route was previously paved but the SPMT transporters still had to compensate for height differences in both the longitudinal and transverse directions to the road. “In particular, we had to make sure that the transport did not move into an inclined position due to the difference in height between the two lanes,” said Stefan Schmidbauer.
The SPMT axle lines moved steadily towards the final destination metre by metre. Even the extremely precise positioning of the bridge on the piers posed no problems. “We had a maximum of two centimetres of play and thus had to work with corresponding precision.” However, the extremely sensitive multi-directional steering and the precisely metered high axle compensation of the SPMT transporters allowed the vehicle operators from Schmidbauer to position the bridge on the piers with pinpoint accuracy.
A major infrastructure project in Germany is the expansion of the ICE connection between Stuttgart and Ulm. Part of the project is the construction of the Filstal Bridge, with a height of 85m, it will be Germany's third highest railway bridge.
The bridge is being constructed by the Max Bögl/Porr consortium. With an overall length of 485m, it is the Deutsche Bahn's largest single structure on this new ICE route, after the main railway station in Stuttgart.
Apart from providing mobile cranes, Wiesbauer supplied equipment for the transportation of 85m-long blue formwork carriage. The formwork carriage bridges the distance between bridge piers and holds the concrete forwork on the yellow booms.
For this heavy duty transport Wiesbauer chose to use its Cometto MSPE self-propelled vehicles. The formwork carriage was moved in an open compound. On one side two MSPE four axle units from Wiesbauer in a side-by-side arrangement, on the opposite side (58m away) a six-axle MSPE belonging to Krebs Korrosionsschutz from Rostock.
For this specific case, the advance calculations had resulted in a maximum permissible lateral tilt of 4.58% with a wind speed of 72km/h. In order to safely comply with these benchmark figures, the transport was moved forward by one day at short notice, because a storm front had been forecast, which could have endangered the procedure. Speed and precision were therefore called for in order to keep to the tight schedule.
The two transport managers, Jörg Neuhäusel from Krebs Korrosionsschutz and Leonard Schmid from Wiesbauer, laid and programmed the data cable between the power pack units, so that the entire vehicle group could be moved with just one radio remote control. In addition, they placed a guiding chalk line on the bridge along which the transport had to move with absolute precision.
At a speed of 0.5km/h, the vehicles travelled from the Ulm side of the bridge over a distance of 485m towards Stuttgart. Shortly before reaching the final position, a cross-transfer track was installed. At a later time, this will shift the formwork carriage into the position of the second bridge axis. And the first beam of this track now had to be overcome.
For that reason, a second Cometto SPMT combination with two six-axle bogies stood ready, also in a side-by-side arrangement.
The obstacle run at a dizzy height began: the two four-axle bogies “handed over” the load over the first cross-transfer track to the two six-axle units. As a result, the distance between the supports grew to a considerable 71.9m and the total weight of load and vehicles was around 438t.
After that, the combination proceeded further towards Stuttgart, the six-axle bogies being set back by 17.4m once again and, after moving the formwork carriage forwards again, set down on the second cross-transfer track. This took place with careful measurement of the position by the engineers on site.
Neuhäusel reduced the output of the power pack units to 20% with the potentiometer on the remote control and moved the entire combination with millimetre precision to the desired position.