TIM B Y: T H E T U N N E L L I N G INNOVATION. TO C R O S S R I V E R S A N D S TRAITS.
FOUR WAY S T O C R O S S A R I VER. WHIC H I S T H E B E S T ?
Mobility has priority. Rivers and straits are a considerable obstacle to the mobility of people and goods – especially in large cities and conurbations. Aswell as mobility, a region’s growth and development can also be impeded. Any solution has advantages and disadvantages. The classic infrastructure solution is a bridge – an architecturally complex construction. In recent decades, tunnel constructions have become increasingly common as solutions for road and rail traffic. When tunnelling beneath water, we distinguish between two procedures: mechanicaltunnelling technology and the immersed tunnel procedure. All three methods have advantages and disadvantages. The immersed tunnel procedure makes large demands on space and requires complex work to install temporary construction site facilities, which are often out of the question in inner city areas. In addition, the time spent transporting the tunnel elements with tugboats and sinking themextends the construction period.
TIMBY. For the strait and narrow.
Both bridge construction and tunnel sinking can lead to interruptions in shipping traffic – an effect which is to be avoided when mobility is the aim. The ingenious alternative is TIMBY. The TIMBY tunnelling technique (patented by Bouygues Travaux Publics) is based on a tunnel boring machine developed by Herrenknecht,which relies on tried-and-tested technologies. TIMBY (Tunnel IMmersed BY BTP) has significant advantages over the conventional immersed tunnel procedure. TIMBY is extremely space-saving, cost-effective, ecological and in the main causes no interruptions to shipping traffic. While the tunnels are under constant construction at the riverbed, shipping continues to flow uninterrupted above. TIMBY meansmaximum efficiency: space-saving little interruption of traffic short construction times minimum environmental impact comparatively low costs
1 Place-saving launch construction for TIMBY.
2 TIMBY sets off towards the opposite bank or shore.
4 The prefabricated concrete elements are transported to the tunnel boring machine through the backup system ...
3 Two cutting mill arms cut thelower tunnel contour into the riverbed.
T I M B Y C O M B I N E S T H E A D VA N TA G E S O F T U N N E L B O R I N G TECHNOLOGY AND THE IMMERSED TUNNEL PROCEDURE. AND THIS IS HOW IT WORKS:
Innovation with a good name. Taking tried-and-tested Herrenknecht technology for shield tunnelling in soft and water-bearing ground as a basis, a specialized, innovative procedure was developed for theproduction of tunnels under water, which also makes most additional work and construction site installations unnecessary. Getting a head start. A cofferdam – a dry area directly on the river bank drained using sheet pile walls – functions as the launch construction for the TIMBY machine 1 . This is ﬂooded after the system has been assembled, and tunnelling can begin 2 . Two milling cutters cut thelower tunnel contour into the riverbed, the excavated material is removed hydraulically. This procedure for material excavation allows a signiﬁcant reduction in preparatory measures to level the construction bed, compared to the immersed tunnel procedure 3 .
5 … and are connected to form the next ring.
6 Steel anchors connect the lining segments lengthways. Steel cables secure the ringsaround their circumference.
7 The lower section is filled with sand; the tunnel can no longer float to the surface.
8 TIMBY enters the target shaft at the water’s edge.
Reaching new shores, segment by segment. The machine proceeds lining segment by lining segment. Each time tunnelling has proceeded by the width of one lining segment, the prefabricated concrete elements are transported...