Tunnel rock recycling
Tunnel rock recycling or utilization is a method to utilize the rock excavated from tunneling into other needed areas besides as a landfill. Concrete contains 50-80% aggregates from sand and gravel and could potentially benefit from using aggregates produced from excavated tunnel rock.
Today's road and railway tunnels are normally covered by concrete in the lining and portal. If the excavated rock was to be utilized as concrete aggregate it would be beneficial both economically and environmentally. It could be more value generating compared to using the excavated rock as landfill or filling up old quarries. Additionally, the need to transport could be significantly reduced as the utilization of the rock could be placed outside the tunnel portal with a processing facility and a concrete bathing plant. The investment cost of this facility would be repaid as the project could potentially be self-supplied on concrete.[1]
By 2018, 7 tunnel projects will have accomplished utilizing tunnel rock into concrete on an industrial level, either as shotcrete or concrete elements in TBM tunneling:
| Project | Country | Year | Km | Million tons(metric) | Utilization[%] | Diameter(mm) | Reference |
|---|---|---|---|---|---|---|---|
| Zugwald | Switzerland | NA- 1998 | 9.5 | 1.2 | 16% | >16 | [2] |
| Gotthard Base Tunnel | Switzerland | 1999-2016 | 57.1 | 28.7 | 23% | >0 | [3] |
| Koralm KAT2 | Austria | 2013-2023 | 21 | 8.6 | 17% | >16 | [4] |
| Follo line | Norway | 2016-2021 | 19.5 | 9 | 10%* | >20 | [5],[6] |
| Lötschberg | Switzerland | 1999-2007 | 34.6 | 16 | 29.1% | >0 | [7] |
| Linthal | Switzerland | 2010-2015 | 3.7 | 1 | 100% | >0 | [8] |
| Nant de Drance | Switzerland | 2008-2016 | 5.5 | 1.14 | 25% | >0 | [9] |
References
- ^ https://brage.bibsys.no/xmlui/handle/11250/2454109
- ^ Materialbewirtschaftung Zugwald-Tunnel 1987. 2001, Amberg Ingenieurbüro
- ^ H. Ehrbar, L. R. Gruber and A. Sala, Tunnelling the Gotthard, Chapter 8. 2016, Esslingen, Switzerland: Swiss tunneling society
- ^ H. Wagner, The successful application of different excavation methods on the example of the Koralm tunnel lots KAT1 & KAT2. Austrian Federal Railways.
- ^ http://agjv.no/no/component/content/article?id=6:innovation.
- ^ https://brage.bibsys.no/xmlui/bitstream/id/321874/Follobanen_st%C3%B8rst%20urban%20utfordrende%20raskere.pdf
- ^ A. Delisio, J. Zhao and E. H.H, Analysis and prediction of TBM performance in blocky rock conditions at the Lötschberg Base Tunnel. 2012.
- ^ B. Raderbauer and A. Wyss, Tunnel excavation material as resource for underground power plants and concrete dam constructions. 2014
- ^ https://en.wikipedia.org/wiki/Nant_de_Drance_Hydropower_Plant