Over 1km has currently been tunnelled on Austria’s 1.8km long twin tube Steinhaus road tunnel. Contractor, Bilfinger Berger had successfully completed 650m of the 1552m long northern tube (pictured left) and 530m of the 1495m long southern tube (pictured right) as T&TI went to press. The remaining length of tunnel to make up the 1.8kms will be constructed in open-cut. Work started in August 2001 at the western portal (pictured). In October that year tunnelling began with the construction of a 47m long central pilot tunnel, within which a buttress between the two main tubes was cast using self-compacting concrete. Excavation of the southern tube commenced at the end of 2001 followed soon after by the northern tube. The tunnels are being progressed as a top heading, bench and invert using a fleet of Liebherr excavators, CAT and Liebherr loaders and Volvo dumpers. The faces are secured by up to nine x 5m long self drilling anchors with rock support by 4m long grouted rebars and self drilling rockbolts. The tunnels when completed in early 2004 will form an integral part of the B306 Vienna to Bruck road.
