Complex Segment Monitoring at Koralm Tunnel
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TJ_0513_OUTSIDE_FNT_COVER_PLUS_SPINE_001.qxd:cover 22/4/13 20:22 Page 1 www.tunnellingjournal.com April/May 2013 TTheunne international journal for the tunnelling industry llingjournal SEE PAGE 18 SEE PAGE 34 SEE PAGE 40 SEGMENTAL PROJECT JUBILEE INNOVATION POLITICS REPAIRS TJ LOOKS AT NEW THE COMPLEX A FASCINATING TECHNOLOGIES WORLD OF INSIGHT INTO AVAILABLE TO THE PROJECT POLITICS AN INTRIGUING SEGMENTAL LINING EXAMINED GROUTING SECTOR PROBLEM TUNNELLING JOURNAL SEGMENTAL LININGS IN FOCUS APRIL/MAY 2013 APRIL/MAY THE KORALM’S SEGMENT TRACKING SYSTEM TJ_0513_KORALM_010_016.qxd:Feature 22/4/13 20:33 Page 10 SEGMENTAL LINING The Koralm Project at a glance Austria's new Koralm tunnel is one of the the west and the harder gneiss of the largest infrastructure projects in Europe outside mountains. Strabag did that work in 2005-07, of the three great Alpine pass crossings at making a small 45m2 cross-section bore. Brenner, the Swiss Gotthard and France's Fréjus. “It was thought this might be a difficult area At just under 33km long and with a maximum but in the end it was more straightforward than cover of nearly 1200m it is at least approaching thought,” says Lehner. the same kind of scale. The interface fixes two different types of The twin bores for high-speed rail trains will tunnelling for the project which uses form a critical link through Klagenfort in conventional excavation in hard clays to the southern Austria and on to the north east via west and switches to TBM for the longer hard Graz and Vienna. Another major tunnel, the rock. This is mainly gneiss, a layered form first, Semmering is also required and is currently with split planes - it is used locally for making under tender by the Austrian Federal Railways, roof tiles – and then solid older rock. which is also the client for the Koralm. The main contract, for some 600M, was The Austrian route section in turn is part of a begun in January 2011 with formation of two key trans-European route, the Axis 23 Adriatic-B deep access shafts and the conventional drives Baltic corridor which will eventually connect heading in both directions. They also saw the Gdansk on the Polish north coast with Venice in creation of two large parallel caverns for the north-east Italy. assembly of the TBMs. The Koralm tunnel has been split into three The Aker Wirth machines, each with a double main sections. A small southern contract has head, arrived on site late last year and the first already formed the portal and an initial began driving in February with the second conventionally excavated 2km of tunnel. It starting work just before Easter. They have an starts near the little town of Deutschlandsberg outside diameter of 9.93m. Swiss firm Rowa sited in the vine and farmland valley supplies the follow on back up train and countryside before the Koralm mountain range. segment delivery equipment. It is almost complete. They erect a six segment ring as they go, five Second and largest of the contracts, pieces plus a full size key element; inner underway since late 2011 is for the central diameter of the rings is 8.8m and the ring portion, with around 2km of conventionally segment thickness is 350mm leaving an annulus excavated tunnel required for each bore and of 200mm which is filled with pea gravel. then long TBM drives through the hard rock of Details of the tunnelling will be explored in a the Koralm mountains. These are slightly follow on article. different lengths, 17.1km on the north side and 15.7km on the south. Both machines have just begun work. Czech Republic The drive length difference is due to previous exploratory works on the third section and Germany Slovakia logistical issues which alter the breakthrough Vienna point on the southern bore, explains Wolfgang Lehner. He is project director for the joint A venture carrying out the work, formed from an I 80% majority of contractor Strabag with R T Austrian tunnel specialist Jägerbau. S “There was a shaft and fairly long exploratory U Hungary A Graz tunnel of around 10km done for the Lot three,” he says. The third contract, to be let shortly, is Klagenfurt for 12.8km of twin tunnel, most to be done by TBM. Italy Slovenia Croatia An exploratory tunnel was also done for the longest central section, to pin down the geology Above: plan map of the Koralm Tunnel as much as possible and particularly to find the location. Below: section showing the interface point between soft glacial ground in construction lots of the tunnel Main construction sections Koralm tunnel Percentage of the overall excavation Neogene sections: Styria East portal NATM 4.1km KAT I: 8% KAT II: 57% Crystalline KAT III: 35% Carinthia TBM 15.7km ult ttal Fa van NATM 5.1km La e/ en TBM 12.1km KAT I g o e N TBM 17.1km KAT II .6km el 10 tunn tory NATM 0.7km lora /exp TM A Shaft: 60m West portal N KAT III NATM: 4.4km TBM: 32.8km 10 TUNNELLING JOURNAL TJ_0513_KORALM_010_016.qxd:Feature 22/4/13 20:33 Page 11 SEGMENTAL LINING KORALM TUNNEL SEGMENTS - complex monitoring and management Strict quality control and tracking requirements are being met with the SDS computerised production control system for the segments going into the new Koralm tunnel in Austria. Adrian Greeman visited the site and files this report DRIVES FOR THE MAIN sections of the segments have been set by the client ÖBB- Koralm high speed railway tunnel project Infrastruktur, the capital works division of began work at the beginning of this year, two Austrian state railways. As well as tight quality 9.9m diameter TBM hard rock bores of 15.7km assurances it wants full traceability of the and 17.1km length respectively form the lines components in the segments to allow for on the north and south sides of the alignment. easier trouble-shooting and investigation in the They will take around three years to complete event of damage or failure within the tunnels. their eastwards progress, meeting eventually The requirements arise particularly from with 12km and 10km drives coming the other caution about potential difficulties in the rock way by another contractor. and particularly in the first seven or so The Strabag-Jägerbau joint venture kilometres of the drives through striated gneiss contractor for the central and largest section of with significant slip surfaces in the rock. For this the project, Lot 2, is pleased with the start it section there is also a very unusual requirement has made on the TBM sections. The first for an in situ lining. machine began in February on the southern “The TBM will install a basic segmental lining bore and the second machine starting work and then we will follow on with a waterproof earlier than expected, just before Easter. drainage membrane and in situ inner shell cast Meanwhile in its first two years, the using a travelling formwork as you would in a contractor has already made some 4.4km of conventional tunnel,” says Strabag project tunnel by conventional methods in soft ground director for the joint venture Wolfgang Lehner. near the western end. But the hard rock drives In the later harder gneiss section the tunnel are the key part of its €600M contract. will use simply the plain segmental lining. A key element of its work in the initial period All these segments must be produced on of the contract has been setting up and site. The client ruled out segment production preparing for the segment production and elsewhere and delivery to site because of the delivery to the machines which will consume potential disruption it would cause. The area is eventually some 103,500 segments for the a pleasant rolling landscape of farmland, rings and another 17,250 larger invert vineyards and small townships. segments. These 13.4t pieces are for a flat floor “The delivery of so many segments by trucks which is installed immediately behind the over a three year period would have been machine and to which are bolted twin railway impossible,” says Andreas Lange, segment tracks for personnel carriers, logistics and production manager. He says that it would also machine supply of segments and grout. have been difficult to bring them in by rail, Strict requirements for quality of the because although there is a line to the site, TUNNELLING JOURNAL 11 TJ_0513_KORALM_010_016.qxd:Feature 22/4/13 20:35 Page 14 SEGMENTAL LINING installed as part of the mobilisation, it does not tolerances,” says Nod Clarke-Hackston, have sufficient capacity. “It is needed for international sales manager for VMT, “and supplies like the pea gravel, grout and so forth even a fraction of a millimetre can set it out.” and for removal of spoil,” he say. The system uses input from modern laser But producing so many segments on site has scanners, two of which in fixed positions can its own difficulties, most of all the space. be used either to scan the interior of a steel Within a tightly constrained area the contractor form or the final segments once removed. The must have not only its tunnel access and spoil factories at Koralm have a measuring space disposal handling but also two segment fitted with Faro scanners. factories and a storage area. “That is very These can work in minutes compared to small,” says Lange. For his purposes, he has a painstaking day long checking with total yard stretching approximately 150m in each stations required in the past. A 3-d best-fit direction from the central tunnel access shafts, volume model is produced.