Two new Steigerwald motorway bridges in just one night

During the last operation, it was only one bridge, this time we increased the operation and installed two steel hollow box girders for the country road bridges over the A3 near Erlangen in only one night.

For this, the section between Heßdorf and Höchstadt an der Aisch was completely closed for 14 hours.

In order to keep the closure of the motorway as short as possible, two different pre-assembly sites with wide access to the motorway had been set up beforehand. Here, the 4 bridge parts prefabricated in our factory in Darmstadt were welded together to form the two 260 and 380 tonne and 70 meter long steel colossi.

In order to transport the two bridges in their full size to the actual construction site, a complicated and unusual technique was required. Two self-propelled heavy-duty transport modules (SPMT) were used for this purpose. They brought the bridge constructions at walking pace over the closed motorway to the places where they were set down free-floating, centimetre by centimetre, at their destination.

The 70 km long motorway section in the Steigerwald between Würzburg and Erlangen will be renewed by 2025. Another 19 steel composite bridges will be installed in the same way.

Successfully connected! “Bridge closure” for the 1st construction phase of the Grumbachtal Bridge.

Darmstadt/St. Ingbert

In mid-February, the last two components, the so-called “bridge closure”, for the 1st construction phase of the Grumbachtal Bridge were successfully assembled.

Even before that, there had been a lot to marvel at in St. Ingbert when the first six bridge components were lifted into place. With the help of a caterpillar crane specially set up for the lifting operation, our assembly team managed to lift the huge steel structures into their final position in a very confined space.

Now the lifting oft he last two mighty bridge sections, each with a length of around 22 metres and a weight of up to 60 tonnes, was once again spectacular. For the crane’s crossing, which was only allowed to take place at night, the traffic over the bridge had to be slowed down for a short time and for the actual lifting, the motorway in the direction of Saarbrücken was even completely closed for several hours, as the components were unloaded on the motorway, turned and then lifted into their final position.

On Sunday, 15 February, the time had come and the first construction phase could be completed precisely and on schedule. The fact that this went so smoothly is largely due to the precise planning work of the responsible assembly engineer and our well-rehearsed, experienced assembly team on site. The components are now being welded together.

At the end of March, our assembly team will leave the construction site as planned and will not return until the second construction phase can probably be assembled in 2022.

Installation of the first Steigerwald freeway bridge in just one night

Darmstadt, 29.11.2020. Our assembly engineers only had one night to install the 260-ton highway bridge over the A3. For this purpose, the A3 was completely closed off between Schlüsselfeld and Höchstadt-Nord.

The preparations had already begun weeks earlier with the installation of a pre-assembly area on a former freeway parking lot shortly before the Schlüsselfeld exit. There the four steel bridge sections manufactured at our plant in Darmstadt were first welded together to form a 70 meter long and 260 ton bridge structure.

Two self-propelled modular transporters (SPMT) transported the bridge structure at walking speed over the closed highway to the construction site two kilometers away, where it was then placed in the bridge bearings, centimeter by centimeter, free-floating.

By 2024, a further 21 steel composite bridges will be installed over the Steigerwald motorway.

Three new superstructures for the railroad line in the Urft Valley

On November 20, 2019, Donges SteelTec was awarded the contract for the design, manufacture and erection of three steel superstructures for the railroad line in the Urft Valley in the Eifel region. One year later, the assembly of the steel structures has now been completed and the overpasses have been opened to rail traffic. The structures are located near the villages of Sötenich and Nettersheim and transfer the railroad line 2631 over the Urft.

They are each trough structures with orthotropic roadway slabs, which are designed as single-span girders. The spans of the three structures range from 15.70 m to 23.40 m. The largest superstructure has a net weight of 107 tons.

All three superstructures were manufactured in our factory in Darmstadt and transported to the construction site by heavy goods vehicle. Within three days, the superstructures were lifted into their final position with a mobile crane. After the sidewalks had been added and finishing work had been carried out, the track is now in operation again.

The many years of experience and the expert knowledge of our bridge construction engineers made it possible to complete the three structures on time and to the highest quality standards. Donges SteelTec thus successfully continues the construction of railroad bridges and makes an important contribution to the maintenance and expansion of the railroad infrastructure in Germany.

 

Precise lifting of heavy steel bridge components

Darmstadt/St. Ingbert

After the start of the steel construction assembly on September 24th, 10 segments of the Grumbachtal bridge have now been assembled. The individual steel components with weights of up to 140 tons were manufactured at our headquarters in Darmstadt to the highest quality standards and delivered to St. Ingbert by heavy-duty transporters.

Massive mobile cranes with a maximum load capacity of 500 tons lifted the heavy steel bridge segments precisely onto their piers. Following the lifting assembly, the individual sections were welded together.

In the coming weeks, further parts of the steel structure (in total 4800 tons) will be delivered and installed, so that the superstructure will arrive at the second abutment before Christmas. Erection of the last two shots is scheduled for early 2021.

Donges SteelTec receives order for the replacement of the Thulba viaduct

The bidding consortium Adam Hörnig GmbH and Donges SteelTec GmbH has been awarded the contract for the replacement of the Thulba viaduct. This involves two superstructures for the A7 motorway bridge between Würzburg and Fulda in the Bad Kissingen/Oberthulba section of the motorway. The bridges, each with a total length of 460 m, up to 53 m above the valley, will cross the A7 over the Thulba as well as various forest and farm roads.

The replacement for the 7-span bridge, which was completed in 1968 and is now to be demolished, is a steel composite bridge that is pushed in lengthwise. The steel construction tonnage amounts to a total of 6,000 tons. “We are very proud to have been awarded the contract together with our long-standing partner, Adam Hörnig GmbH”, said Stephan Langer, Managing Director Bridge Construction of Donges SteelTec GmbH. “Such particularly challenging structures are our hobbyhorse and we are delighted to be able to help design such magnificent bridges”. The client is the Autobahnamt Nordbayern, for whom Donges SteelTec has already built the Heidingsfeld and Breitengüßbach viaducts. Construction will start in the autumn of 2020; the construction time is estimated at around six years.

New railway overpass over the river Steinach: Installation is proceeding successfully

In the middle of May the assembly of the new railway overpass over the Steinach in Balingen has started. First of all a supporting structure was assembled on which the newly manufactured bridge sections could be placed and welded. After the carriageway slabs were placed on the support structure as the first components, the two large trussed slabs were lifted in. Assembly was not easy here because the 44-metre long trusses had to be delivered backwards under the old railway bridge. This proved to be a big problem due to the low clearance height: The trucks could not pass completely under the bridge. The solution was to lift the long trusses under the old existing bridge using a 700 tonne crane. The crane thus unloaded the trucks, placed the components next to the support structure, erected them and lifted the 64-tonne trusses onto the support structure. A great deal of sensitivity was required here, as the railway traffic on the existing bridge was not stopped during this time.

After this assembly phase, support structure was completed and then the smaller trusses were lifted in. Currently, the entire bridge is being welded and the corrosion protection is being completed. The work is proceeding according to schedule.

Following the steel construction work, the client will dismantle the old existing bridge and will move the new bridge to its final position.

 

Second construction phase successfully installed

With the lifting of the A46 Westring bridge, an eventful April came to an end for our bridge builders. In the night from April 25 to 26, the 2nd construction phase of the motorway bridge was successfully installed.

Two 300 t cranes at the abutments and a 750 t crane below the bridge ensured that the steel components could be lifted in. The parts were delivered over the bridge, which had already been built in the 1st construction phase, by means of heavy transporters, slewed by two cranes and set down on the new piers.

First, the two outer bays were lifted, each consisting of two hollow boxes with a length of approx. 37 m.  Then followed the end cross beam and the cross beam on the pier. Thus the two hollow boxes were connected with each other.

Finally, the bridge was completed by the two 18 m long central components which were delivered underneath the bridge and lifted in place with the 750 t crane in a single lift.

The total length of the three-span composite steel bridge is 105 m with a total superstructure width of 36 m. 1000 t of steel were used for the entire steel construction of the structure.

Another milestone successfully completed

The second shifting of the bridge north of Bamberg was successfully completed by our technicians on the weekend 17th/18th April 2020.

In the course of the replacement and reconstruction of the Bridge 93b of the BAB A73 Bamberg-Lichtenfels, the steel construction (approx. 1,400 tons) of the steel composite structure was shifted by 45 m over the B4 and the railway line to be crossed with the beginning of the closing break of the German Railway on Saturday and reached the auxiliary pier as planned.

On the following Sunday, the remaining shift took place with a total of 70 m to abutment 40. During the next weekend operation the bridge was then stacked by 1.30 m to its intended final position.

The composite steel bridge consists of two separate superstructures (section 1, Lichtenfels carriageway and section 2, Bamberg carriageway). The two separate superstructures are antimetrically designed, geometrically particularly challenging trough structures made of steel with a concrete roadway slab. The total length of the three-span bridge is 150 m with a total superstructure width of 37.20 m. For the entire steel construction of the structure 2800 tons of steel are required.

 

Successful lifting of the new railway bridge

In Riederich, two thick plate bridges with an individual weight of approx. 37 tons were placed on the new abutments. The railway overpass consists of two separate superstructures. Each superstructure is designed as a trough bridge with thick plate. A walkway is attached to one side of each of the two superstructures. The span of the bridge is approx. 6.10 m, the construction height is 0.8 m. Each of the superstructures has a width of 4.48 m. The footpaths have widths of up to 1.19 m.

The bridge sections have been placed on top of addition stacks and remain on these until the bearings have been cast. Afterwards the footpaths were added.

In this state the bridge is now waiting to be moved to its final position together with the two abutments.