INCREDIBLE SWITZERLAND BIGGEST TUNNEL BORING MACHINE DIAMETER-HOW DOES TUNNEL BORING MACHINE WORK?

Let's take a closer look at the equipment used to

work

in the

tunnel

. The processes in the mountain are fascinating because with the construction equipment developed by Marty and the

tunnel

boring

machine

, an entire tunnel factory runs through the mountain. The cutting heads are 40 meters high. The cutting wheel breaks rock fragments from the rock when they are rolling. The number and arrangement of the bits differ depending on the rock. Marty optimized them for Belkin geology. Through injection openings, the stabilizing material can be placed in the rock. directly behind the cutting wheel with up to 2000 tons of contact pressure the entire

machine

advances along the already constructed tunnel the space between the tunnel and the rock is filled with a fast-curing mortar the machine stops every two meters inside of the protection of its own shield builds a seven-segment tunnel ring with segment construction the tunnel is secured by the first ring closure directly after excavation the lifting plate is vacuum-operated experienced teams build a complete segment ring In approximately 25 minutes the segments are produced in Marty's own high-strength steel factory.

The fiber concrete also makes the edge areas of the segment rings extremely rigid. Outside of the reinforcement, the filled form

work

passes through an oven. of 55 degrees for the seven segments of a segment ring There are also seven ways in the rotation The segment ring is unique and allows for different tunnel curves in 13 mounting positions, the development of the tunnel curve is determined by the order delivery already at the segment plant, while the machine continues drilling, complete removal of dust from the air directly behind the cutting head is essential for tunnel work. The excavated material is transported out of the tunnel at the end of the machine as the machine moves the belt is continuously extended and suspended from the tunnel vault due to the high risk of swelling of the rock marty builds an additional solid interior vault in the tunnel after the first excavation protection by voussoirs for this should not be interrupted the supply and removal of the tunnel

boring

machine the installation of the ronesco roof membrane in the lower area of ​​the tunnel begins the membrane is extremely resistant to weather and pressure only thanks to this membrane the tunnel becomes truly waterproof after sealing the floor of the tunnel can be concreted thanks to access to the tunnel boring machine the work is carried out under the passage bridge the formwork for the concrete works hangs movably under the bridge it is inserted into the area concreted the day before the formwork is extremely variable because the project requires walls with and without reinforcing iron and different wall thicknesses the concrete is introduced by a concrete pump every day 10 meters ahead the concrete is concreted marty produces the concrete in a mobile concrete plant on the construction site the reinforcement cages for the next stage of concrete are installed in parallel in front of the formwork the extremely heavy cages are difficult to tow under the bridge the supply traffic for the TBM continues to circulate over the bridge once a day, when the ground concrete dries, the entire bridge With the formwork, a 10-meter stage is advanced, then the former is prepared under the bridge for the next concreting on the bridge, the path to and from the tunnel boring machine is again cleared. especially pleasant place at lunch time now the service gallery extends to the bridge the lateral gaps are filled with excavation material thus finishing the tunnel floor in the outer structure the vault is now clear for the expansion of the upper area of ​​the tunnel passes the tunnel ventilation through the service gallery and the ventilation air ducts suspended in the vault, the air duct moves periodically, here shown only schematically, the conveyor belt which is also suspended from the vault of the The tunnel is deposited on the floor of the tunnel by the belt conveyor truck in a flat curve that

does

not impede the operation of the belt.

Now the vault is free and can be reinforced since the base work begins with the roof first being attached. the sheets to the segments with hot glue and then the sheets are welded together using hot air fans each seam is made up of two directly adjacent welding lines the scene can only pass quality control if no air escapes from the space between the sheets during the compressed air test now the tunnel is ready for the installation of the inner vault first the reinforcement cages are placed moved the reinforcement vehicle places the cages precisely in their position and fixes them with its rotating arms all places to Subsequent work is easily accessible via mobile working platforms.

Reinforcing 10 meters per day would not be possible without prefabricated reinforcement cages. You only have to manually reinforce the last gap in the ridge area of ​​the tunnel. The vault can then be concreted. The arched structure runs along the tunnel folded. It is very mobile and can be adapted to different wall thicknesses The head formwork elements are folded into gaps in the reinforcement and extruded to the segments The elements are joined with roof pieces and sealed against the segments with a hose compressed air the concrete spreader runs through the formwork work the formwork is filled evenly via the mobile distribution station with rotating conveyor lines the formwork must transport up to 400 tons of liquid concrete and is extremely solid the high-strength formwork is fitted with precision to the millimeter and then the concrete flows again the functionality of the formwork allows a concreting stage every 24 hours to ensure that the pressure of the liquid concrete

does

not displace the formwork the concrete is concreted symmetrically on both sides a comparison with the segments shows the tremendous resistance of the interior vault, which is why thermal insulation prevents the solid concrete from cooling too quickly and cracking.

Finally, the intermediate ceiling is concreted. The area above the ceiling subsequently serves as a smoke outlet in the event of a fire. The concrete is supported on tables. of solid formwork until complete curing occurs the last table in each box is folded and transported to the next concreting stage under the other tables by means of a transport card after completing the intermediate roof the tunnel area in the hull It is completed with the intermediate roof tables, the vault formwork, the reinforcement, the hot melt adhesive, the conveyor belt vehicle and the bridge. Marty has created a complex choreography of special equipment that allows the tunnel to be built directly behind the TBM.

The good interaction of the equipment is no coincidence, as marti technic has planned and built all equipment in its own plant in Mossetdorf, an experienced team of designers for many years and close collaboration with equally experienced metal construction workshops They guarantee high quality products. The complex control systems of the devices were also developed by Marty, carried out in his own electrical workshop and finally delivered to construction. The site along with the system components are built in the factory. Usable excavation material is stored here and used for backfill. Unusable material is transported to the mountain through the construction system produced by marty. 150 meters above the construction site an inoperative stone quarry is filled.

The renovation of the original tunnel tubes will begin operation in 2021. Only good functionality in combination with special devices developed by Marty will allow a solid replacement tunnel to be built in the difficult Belkin geology.