Letzter Blick vor Eröffnung: Deutsche Bahn präsentiert die Filstalbrücke

Welcome to Filstal today. Today you will have the opportunity to travel with me and explore the many hidden corners of this exceptional building. The film is shot in 360-degree format, which means that you have the opportunity to freely look around you in the picture. And now let's go up to the bridge. Well, the Filstal railway flyover consists of two single-track bridge structures. These are spaced 30 meters apart. They are connected to each other by short bridges in the stapes area. The Filstal bridges have a length of 500 meters and a height of about 85 meters. The main span is 150 meters, the main pillars are hollow, the other pillars are monolithic, so they have a complete cross section.

The deep foundations have a depth of up to 25 meters and the structures connect two tunnels, the Bossler tunnel on the Stuttgart side and the Steinbühl tunnel on the Munich side. This tunnel-bridge-tunnel constellation is also quite special and brought some challenges in the implementation of the project. The two bridges are part of the high-speed line and are therefore also designed for a nominal speed of 250 kilometers per hour. Plate track was installed here, so there is no gravel construction. For this speed, a plate track of this type is necessary. Both structures contain, among other things, the so-called sonic boom structures, which are hoods with specific opening grilles and which should also reduce micropressure sound emissions, that is, this explosion that occurs in high-speed traffic is reduced. . here.

Now the project is in the testing phase and test drives began in the summer. On the correct track, that is, in the direction of Munich, and from autumn the test trains will run on the track in the direction of Stuttgart. We are now at the cross section of the Filstal Bridge. Test drives are also happening for us right now. We were not yet at the full box. We have not yet presented the building from the inside. Today this possibility exists. The structure is designed as a single cell full box cross section, as we all know, the structure is very thin.

The superstructure has external dimensions of 8.40 meters wide and that can be seen very well here. Furthermore, the structure is also designed as a continuous beam, as we can see here there is no joint, so the structure has no joints in a length of 500 meters. The superstructure of the structure is a continuous, seamless beam. In this case, the possibilities exist later, or it is even a requirement of Deutsche Bahn that railway bridges also have to be inspected from the inside, i.e. every square centimeter of surface is also examined every six years and is technically examined for detect damage.

The Filstal railway overpass was built to a special design. Semi-integral construction: This means that all the pillars are monolithically connected to the superstructure and it is precisely at one point, in a main part, where we stand upright and can even enter this pillar, that is, in the diagonal braces of the Y. -pillar. And we're going to do that right now. Let's get the boarding aid out and now we can enter safely. Well, here on the diagonal struts there are also access possibilities. Here the stairs are formed, you can enter, so there is also a cavity here and therefore this room can also be inspected.

Here we only reach the monolithic knot, which can also be seen very well from the outside. So, the Y pillar is formed by the axis of the pillar and the two diagonal braces and it is at this point where these three dividers come together and form a Y pillar. Now we look at the state of the construction. Back then, the first step was to raise the pillars and, once the superstructure was finished and supported on the auxiliary supports, these diagonal struts were concreted underneath. And now let's take a look inside the main pillar. Now I am in one of the two main pillars.

Unlike the other pillars, the two main pillars are hollow. As you can see here, beam platforms are installed every five meters, which means that there is also the possibility of examining and inspecting the main pillars from the inside, that is, every square centimeter of this area. Back to the superstructure. The two Filstal bridges are prestressed in the longitudinal direction. In the transverse direction they are slightly reinforced, what does this really mean? I will explain this using a model that I have in my hands. Prestressing works as follows: Prestressed prestressed concrete is a type of reinforced concrete, only the steel inserts, for example the steel insert in our test or tendons, which receive an additional tensile force, so I pull a end like this and after this The force acts and therefore an additional compressive stress arises in the concrete.

That is, the concrete parts, which without prestressing would be loose, so that a deformation would occur in the building, that is, a greater deflection in the middle of the section, the use of prestressing results in a straight building with minor deflections . This means that the bridge deforms less and thus we achieve larger spans. Here, for example, we were able to implement spans of up to 150 meters with this construction method. Kilometers of prestressed steel have been installed on both Filstal bridges. The prestressed steel is then firmly anchored to the structure at certain points. Here we see places where a force is actually applied, the so-called tension threads.

These are the anchor points here on the ceiling, on the floor slab, on the walls. We have these points spread out throughout the structure, so our structure can safely handle this big stretch here. Well, the building has no joints, but there is a joint on one side in the pillar area. There the structure can be lengthened or shortened. That is where deformation occurs, depending on the season, temperature and other influences that affect the structure. On the other hand, the building is firmly anchored to the ground and now we go there and take a closer look. I'm standing here now on the running board above the separation line.

We see that the superstructure and the pillar are firmly connected to each other by this special blue piece, the so-called spring sheet. The spring leaf fulfills the following function here: it has to transmit the braking forces, i.e. the braking forces acting here, i.e. a maximum of 600 tons, only the braking forces, must be transmitted from the superstructure to the abutments, and the slender main pillars cannot do this to their full extent, so a special construction has been developed and implemented here. Since we have implemented a special construction here, i.e. the two bridges are built in a special construction with some deviations from the Deutsche Bahn standards, it is necessary that we also have different components, i.e. pillars and superstructure, but also the pillar for at least five years metrologically controlled at least five years after commissioning.

There are countless sensors, some embedded in the concrete and others glued to the surface of the component. For example, here are the eight extensometers and they measure the deformation due to the different impacts of the operation of the two bridges. So if we go further, we will be able to trace the flow of forces. The forces of the superstructure pass through the elastic battens to this strong, monolithic abutment anchor block and then disappear behind the wall, where the supports are anchored again with 21 anchors that sink up to 30 meters deep into the subsoil. In this way the entire construction, that is, the entire bridge, is firmly anchored in the subsoil.

In this way the transfer of forces can also be guaranteed. In fact, we implemented four bridge structures here as part of this project. So, two main bridges and two smaller connecting bridges. The two structures were needed as part of a rescue plan. Now we leave the pillars firmly anchored and move to the other side of the structure and look at the moving side there. We are now on the side of the BAB A8 motorway in the direction of Munich and we are heading towards this spur. Here the structure is allowed to deform. We look at this dividing line and the storage system that formed here.

As I said, the superstructure is firmly connected on the other side, a fixed point was formed and firmly anchored. In this case, the superstructure can deform depending on the temperature, other influences also play a role, creep and shrinkage of the concrete also play a role. But at most, this joint can open up to 70 cm. Since the superstructure in this abutment is mounted flexibly, i.e. it represents the movable end, all integrated components, such as drainage pipes or this transition construction, must also be configured movably. We can also see here that this drain component can be lengthened and the same goes for this cable, which is also flexible, and all the other transition constructions.

Here again the board upstairs and the storage bench, which is located on the other floor. I hope you really enjoyed today's tour. You have learned and seen a lot. On December 11, the entire line will be operational, so buy a ticket, hop on the train and enjoy the views. For my part, just one recommendation: buy a ticket for a regional train, because you will enjoy the journey and the beautiful view a little more, because an ICE with 250 passes over our bridge in just seven seconds.