New separation technology for Swiss Eppenberg 19 Oct 2017

After more than 20 years in microtunnelling, Swiss subsidiary of Bauer and producer of separating plants, MAT Mischanlagentechnik has entered the large diameter tunnellling market with supplies to the Eppenberg Tunnel project in the Swiss Canton of Solothurn.

The BE-2550 treats 2,400 m³ slurry per hour

Located in Immenstadt im Allgäu, the company has introduced the BE 2550 for use on the 2.6km double track Eppenberg Tunnel. The tunnel is at the heart of the four-line expansion of the railway line on the Olten-Aarau route, which is the busiest railway route in Switzerland. This is a key project for railway traffic in the Swiss Central Plateau region and for the entire country. The expansion will open up options for the regional railway network and for long-distance travel.

A 2,400-tonne 115m long by 12.75m diameter TBM started construction of the tunnel in November 2016 and has been operating in hard rock open mode. For the remaining 700m, the fluid-supported "slurry" technology is being used with the help of the BE-2550 from MAT. Breakthrough is expected at Gretzenbach in the next few months.

The BE-2550 comprises six adjoining identical standalone plants and is capable of moving 2,400m³ of slurry per hour in a closed circuit system. The bentonite slurry transports the excavated material continuously to the separating plant via a 3km-long pipeline. In the separation plant, the bentonite slurry is separated from the soil in multiple process stages using screens and hydrocyclone. It is then fed again into the slurry circuit and delivered to the TBM cutter head. Two continuous mixing plants ensure continuous production of bentonite slurry.

With a length of 22m and width of 26m the BE-2550 is able to help overcome the highly complex technical and logistical challenges encountered in this project.

“It is the result of perfect teamwork within the entire project team,” said Kurt Ostermeier and Kathrin Solbach, Bauer project managers.

The plant underwent factory acceptance testing in Immenstadt, where 25 trucks were loaded in just five working days, and was commissioned in Switzerland.