Using special handling equipment, fabrication operatives stack a complete 'ring' of reinforced concrete tunnel lining segments.
As a Tunnel Boring Machine excavates a passage under the ground (unless this is through hard and non-faulted rock), the tunnel must be lined to prevent collapse and the ingress of water. This lining is usually made of prefabricated and steel reinforced concrete segments (made watertight with special gaskets) that will create a support ‘ring’ or ‘tube’ in the bored tunnel. As most tunnels are designed to have an expected life of 100 years (or more) and are being increasingly excavated in areas of difficult geological conditions, these lining segments must be made with great precision and accuracy from the highest quality materials. The supply of segments dictates the speed of the tunnel’s advance, so, on large tunnel projects, they are often manufactured on the tunnel site in special fabrication plants. As every tunnel is unique and tunnels don't run in conveniently straight lines, linings must be adjustable to allow changes in alignment and levels without compromising the fit of the concrete segments or gasket seals. Concrete is a complex substance which must it be sufficiently workable to reach all corners of the mould but be stiff enough in a short time to retain its shape when the mould cover is opened. The precision and quality of the concrete segmented lining is a vital component in the eventual success and longevity of a 100-year tunnel.
Size: 5120px × 3407px
Location: United Kingdom, UK
Photo credit: © qaphotos.com / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: -vi, accuracy, assembly, assessment, bored, boring, burn, cage, cast, chemical, concrete, construction, drilling, durability, equipment, erection, excavated, expanded, fabricate, fabrication, fibre, gasket, gloves, grout, handling, hard, hat, helmet, high, industrial, industry, infrastructure, ingress, iron, key, leakage, lift, lifting, lining, machine, manufacture, manufacturing, mesh, operatives, penetration, permanent, personal, plant, polypropylene, ppe, precast, precision, prefabricated, pressure, protective, quality, reinforced, ring, risk, rock, safety, seal, seepage, segment, segmental, soft, stacking, steel, substructure, subterranean, support, tbm, tight, tolerance, tunnel, underground, visibility, water, wedge, workers, workforce
