Influence of Clogging on the Muck Transport in Shield Machines

Shield drives in fine-grained clayey soil are frequently affected by clogging. Walls of clogged material represent a special form of this particular obstacle. Such walls can attain a high degree of strength and develop directly in the TBM’s material flow. The fact that these walls of clogged material exacerbate or even interrupt the direct path of the excavated material from the rear side of the cutting wheel to the follow-up conveying system makes driving especially difficult (Fig. 1).

Conveyance of the excavated material from the cutting wheel towards the rear must therefore be carried out by a circuitous route with the material first being lifted by the cutting wheel and then transferred upwards. From there it moves backwards in the excavation chamber over the top of the walls of clogged material towards the suction inlet or in the case of the open mode EPB shield, towards the screw opening.

Such phenomena have been observed both in the case of unsupported open-mode EPB drives as well as in fluid-supported slurry shields, where the excavated material has to be transferred...

Related articles:

Issue 2019-06

Clean Material Separation: Breaking out the Temporary Top Heading Invert in the Trimberg Tunnel

Numerous structures make the new building of the motorway A44, a link between the motorways A7 at Kassel and the A4 at Herleshausen in a west-east direction, a challenging infrastructure project....

more
Issue 2016-05 TBM Technology

“U-shape”: First Shield Machine for horseshoe-shaped Cross Sections

On 17 July 2016 the workshop acceptance was completed by the project owner for the world’s first U-shape (horseshoe shape) TBM, which is manufactured by CREG (China Railway Engineering Equipment...

more
Issue 2011-02 Singapore

Metro Network in the Lion City Singapore

The Asian city state of Singapore has experienced an enormous economic growth over the past few years. The requirements placed on the transportation infrastructure of this metropolis (5 mio....

more
Issue 2010-02

Mechanized Tunnelling for two new Metro Lines in Rome

Rome, the Eternal City, is famous, amongst other things, for its wealth of archaeological sites revealing the city’s historical roots. No matter what means of transport you use when visiting the...

more
Issue 2009-01 Germany

Finne Tunnel: Driving Operations running smoothly

Driving Operations at Finne Tunnel

The tunnel consists of 2 parallel tubes with an external diameter of roughly 11??m, a 45??cm thick segmental lining and connecting passages set every 500??m between the tubes. This results in 13...

more