Microtunnelling is an efficient and environmentally friendly alternative to open-trench construction. This trenchless technique offers precise line and level installations in various ground conditions (including rock).
Most of the functions of the microtunnelling operation are computer controlled or assisted. As such the workforce does not routinely work in the tunnel. It is accurate to industry standard tolerances (British Tunnelling Society) and thus is suitable for gravity sewer installations. The machines can be operated from either shafts of cofferdams.
Micro tunnelling is particularly suited to the urban environment where the disruption of business, traffic and other utilities is not acceptable for commercial, political and safety reasons
The majority of microtunnelling work is carried out using slurry TBM’s (Tunnel Boring Machines). These offer the ability to work below the water table, using the slurry as a transport medium for the excavation arisings and to balance the ground water pressure. Excavated material is separated from the liquid by a specialised plant situated at ground level. The liquid is then recycled, being sent back to the TBM and forming a closed loop system. This method of excavation also enables construction of pipelines within challenging ground conditions without any type of pre-treatment or ground water control. This type of TBM can also be configured to work in rock.
Another of the advantages provided by microtunnelling is the minimal ground movement caused during installation.
Terra Solutions Ltd owns and operates a range of slurry microtunnelling TBM’s
which are able to work in the most challenging of ground conditions, including strong rock. Our experience with this rugged and powerful equipment gives any Client the confidence to employ this technique even in the most difficult of circumstances.