GFRP rebars for softeye's in tunnels

Fortius supplies different strengthening products for the tunnelling industry and all civil engineering applications throughout the world.

*Steel- and polypropylene fibers are used to manufacture prefabricated tunnel segments and used as reinforcement in shotcrete (gunite).

The use of synthetic fibers for plastic shrinkage control and fire-resistance endurance in tunnel linings is growing.

Steel fibers or structural synthetic fibers, used in stead of conventional steel reinforcement, can provide superior performance with reduced costs from materials, time and labour.

*Glassfiber rebars are used to stabilise the front of tunnels (NATM) and to make a “Softeye” in the start- and/or end-shafts for tunnelling with TBM’s.

Breaking through the reinforced concrete of the shafts with a TBM has always been a challenge for the tunnelling contractors. This because the TBM can not dig through the wall reinforced with conventional steel reinforcement. But this problem has been resolved through the development of the GFRP rebars. These glassfiber rebars have twice the strength of steel rebars, but can easily be cut by a TBM. This makes them ideal as reinforcement in the area were the TBM will exit or enter the shaft. This are is called the “Softeye”. Recent references of the use of the GFRP rebars are at the Pesca Nova project of Somague in Portugal, the Thessaloniki Metro, the Docklands LRT in London, Barcelona Metro and in Brussels.

GFRP rebars for softeye's in tunnels