On the occasion of the IUT in Sargans, Switzerland, the WIRTH company received the innovation award for their break-through technology in tunnelling construction. Every three years, the experimental tunnel Hagerbach, researching, testing and developing on behalf of underground mining, affords a special ambience to professional visitors and exhibitors.

 In the tunnelling systems of 5 km length, construction methods, machines and equipment are presented live. As a result of the authentic framework, helmet and sturdy shoes will be advisable in the cragged and not always dry tunnel. During a press conference, Niko Kleuters, C.E.O. of the WIRTH company, received the innovation award 2005 for the successful application of a novel technology. This technology can be seen in operation in the Uetliberg-tunnel, the heart of the traffic relieving bypass in the west of Zurich. "First of all, the pilot tunnel Uetliberg had been driven with a TBM of 5 m diameter. The break-through of the TBM, also a WIRTH product, took place in February 2002, after 2700 m tunnel driving and a construction period of nine months. I

n parallel, this period has been used to advance the planning and manufacturing of the cutter head with the back-cutting technology. "In October 2002, it was the time the novel cutter head with its impressive dimensions was inspected by a delegation involved in the project." That reported Thomas Murer, divisional director of MURER-STRABAG. Meanwhile, the tunnel boring extension machine is boring for the first time according to the back-cutting principle.

Thereby, the corss-roller bits of the cutter head will not be pressed an right angles angainst the rock in order to establish a pressure to destroy the rocks but are lightly sloped in an angle of 10° so that they "shear off" the rocks and "cut themselves into" the mountain. Felix Amberg of Amberg Engineering describes the application of the WIRTH technology at the Uetliberg as a "groundbreaking innovation". "The great expansion in the towns and the increasing requirements for infrastructural projects, such as high-speed trains and motorways, will alone in Europe and Asia necessitate approx. 5,000 km of traffic tunnel within the next ten years", forecasted Prof. Dr. Alfred Haack, managing chairman of STUVA during the IUT.

Source: bauMagazin 11/05
Source: NODIG-CONSTRUCTION