Southern Metropolitan Highway to Decongest BilbaoThe A-8 motorway is integrated into the trans-European transport network (TEN) and is the main distributor backbone of the metropolitan road network in Bilbao, Spain. It serves both through and incoming traffic and serves as local internal traffic as well. Faced with growing congestion problems generated by this confluence of traffic, the Biscay provincial council, through its public company Interbiak, has started work on building the southern metropolitan bypass, a 36 km-long alternative to the A-8 which will channel through traffic providing adequate service levels and will allow demand-side management measures to be adopted for local internal traffic. The new toll bypass road will be tunnelled along 50% of its length, a design which will help curb environmental impact but entails considerable economic cost. Tunnel Type Phase Section Length (m) Urioste Cut-and-cover IA Ugaldebieta-Ugarte 85 / 135 Argalario   Drill-and-blast IA  Trapagarán-Gorostiza 1,816 / 1,794 Mesperuza IA 561 / 590 Santa Agueda IA Gorostiza-Cadagua  1,964 / 1,980 Arraiz IA Cadagua-Peñascal 2,263 / 2,261 Cadagua IA Enlace del Cadagua 247 Larraskitu IA Peñascal-Larraskitu 831 / 894 Arnotegi IB Venta Alta 1,745 Seberetxe IB Venta Alta 510 Seberetxe Cut-and-cover IB Venta Alta 75 Tximintxe Drill-and-blast IB Arrigorriaga-Galdakao 1,165 Tximintxe Cut-and-cover II 65 San Antón Drill-and-blast II 2,760 Bekea II   Bekea 860 Burtozamendi II Bekea 1,450 Murrieta III San Fuentes 1,020 / 585 Gallarta III Ortuella-Trapagarán 4,350 Zaballa III 270 The southern metropolitan bypass motorway in Bilbao, also known as "Supersur", is comprised of three main interventions that consist of a new highway between Trapagarán and Venta Alta (14 km, of which 8 km in tunnel), an enhanced junction to motorway A-8 and a third lane between La Arena and Abanto, and the increase of capacity and improvement of the junctions to the A-8 in Portugalete-Ortuella-Santurtzi and Santurtzi-Port of Bilbao. The total bill for the project amounts to EUR1,350 million, financed by a loan granted by the European Investment Bank (EIB) up to 55% of the cost, annual contributions from the Biscay provincial council (for more than 30 years) and toll revenue. The southern metropolitan bypass motorway has been divided in three phases. The construction of the first phase between Trapagarán and Venta Alta in Arrigorriaga will be subdivided in eight different sections as part of Phase 1A. The different construction sites are grouped according to whether they include tunnels or not, because this implies longer or shorter construction times. Sections 4, 5, 7 and 8a involve the construction of tunnels and have been awarded in March 2007. The time frame for construction is 32 months for all the sections. Phase 1A is scheduled for completion and service operation in 2011, which requires a tight schedule for design (2004-2006) and construction (2007-2011). The ninth section Peñascal-Venta Alta forms part of Phase 1B, which will be built during the 2011-15 period. The first phase represents an investment of more than EUR771 million for 10 kilometres of road, whereof eight will run through tunnels. Click es/118. View photos here.Tenders for the safety equipment (ventilation, lighting, fire detection, signposting, etc.) will be invited separately and will be part of another contract for all the sections.The other sections of Phase 1 without tunnels have been awarded in November 2007: Larraskitu-Buia, the Cadagua junction, the Trapagarán viaduct and the Ortuella-Portugalete junction. Two sections are still pending (Santurtzi-Portugalete and Portugalete-Trapagarán). The remaining stretches, Santurtzi-Portugalete (2b) and Portugalete-Trapagarán (3a), will be tendered later on because they are less complicated.In 2012, the EUR336 million second phase (Venta Alta-Galdakao) and the third phase (Trapagarán-Muskiz), budgeted at EUR244 million, will be launched. The second phase is scheduled to commence in 2012 to end in 2015. Visit http://interbiak.bizkaia.net/variante/ca_planning.htm Section 4 Trapagarán-GorostizaSection 4 Trapagarán-Gorostiza has been awarded for EUR117.4 million to a joint venture of Murias, Pavisa and Otaduy. Visit www.muriasgrupo.com and www.enrique-otaduy.comThis section includes the Argalario and Mesperuza tunnels, respectively 1,816 m long (Santander-bound) and 1,794 m long (Bilbao-bound) and 561 m long (Santander-bound) and 590 m long (Bilbao-bound). These lengths correspond to the mined parts of the tunnels excavated by means of explosives. In addition, each tunnel mouth is built using the cut-and-cover methods (54 metres in the Cantabria-San Sebastián direction and 58 metres in the San Sebastián-Cantabria direction for the Argalario tunnel and 112 metres in the Cantabria-San Sebastián direction and 110 metres in the San Sebastián-Cantabria direction for the Mesperuza tunnel).The typical cross-section for three lanes consists of an outer face of 119.8 square metres and a finished inner face of 100.7 square metres. On the other hand, the cross-section is different according to the type of support that is implemented. The main Argalario tunnels are connected by six pedestrian cross-passages, 3.48 m high and 2.46 m wide (9.4 sq m) and one for vehicles, 3.95 m high and 5.90 m wide (24.1 sq m). In the Mesperuza tunnel, there will only be pedestrian cross-passages. GeologyOn the Trapagarán-Gorostiza section, materials belonging to the Ereza, Tejera and Ortuella formations have been surveyed. Along the tunnel length, three types of materials have been identified, composed mainly of calcareous sandstone, siltstone more or less calcareous, siliceous sandstone and calcareous and sandy layers of the Ereza formation, carbonated siltstone with abundant highly calcareous compounds (marls), nodulous limestone and siliceous sandstone of the Tejera formation, calcareous siltstone with turbiditic intercalations of siliceous sandstone of the Ortuella formation and superficial formations consisting of anthropic backfill and elluvial-colluvial deposits. Tunnelling methodThe tunnels have been attacked first by installing double casing crowns of bolts with individual cutting of 36 mm-diameter 6 m-long holes and then pipe roofing with 20 m-long 150 mm-diameter steel pipes. Then, the tunnels are excavated using explosives.The bored cross-section equals approximately 115 square metres while the finished cross-section is approximately 105 square metres. Initially, the top heading is driven (65 sq m) and after breakthrough of the tunnel, the benches will be excavated (40 sq m). Then, final concreting works of the tunnel will be performed.The Argalario tunnel is attacked from two sides, which means there are two drives per tube. The Mesperuza tunnel is attacked only from the westernmost side, with one drive per tube.Three-boom drill rigs are used: two Atlas Copco WE3 C18 and a Sandvik Axera T11. The explosive is Goma 2 ECO of Maxam, supplied by their Galdakao factory in Biscay, bulk ANFO, electric and non electric detonators, and 100 g/m and 6 g/m explosive cords. Two Charmec 9910 BC ANX 1000 explosive chargers of Normet are also employed. Visit www.boomer-rig.com, www.sandvik.com or www.miningandconstruction.sandvik.com, www.maxam-corp.com and www.normet.fiAt the beginning of April 2008, the Cantabria-bound Argalario tunnel, east portal, had been bored on a length of 13 metres while the progress was 12.80 m on the south bore. Advance at the Cantabria-bound tunnel (northern tube) of the Mesperuza tunnel, western portal, was 32.10 m. Rock haulageLoaders, articulated dump trucks and track excavators with ground breaking hammers are used to remove the blasted rock. The number of vehicles depends on the length of the tunnel and the distance to which the excavated material produced by the blasts has to be transported. The suppliers of this machinery are still unspecified. Primary support and final liningThe support techniques and pattern depend on the ground type that is crossed. The supports required include, in some cases, bolting and subsequent shotcreting. In other cases, steel arches, 5 x 15 x 6 mm welded mesh and shotcreting is necessary. Bolting is carried out by means of two Atlas Copco Boltec LCs. The bolts are 5 m long and 25 mm in diameter and made of corrugated steel supplied by Maiuna. Minova supplies 28 mm resin cartridges. Visit www.minovacodiv.comThe shotcrete is supplied by Hormigones Basurto, the steel fibres are Bekaert's Dramix and the accelerators are supplied by Sika and BASF. A Meyco Potenza BASF shotcreter is employed. TH-29 steel arches are supplied by Auxiliar de Entibación and they are placed with a Manitou telescopic handler. The final lining is 30 cm-thick mass concrete. Visit www.bekaert.com/building, www.sika.ch/en/stm.htm, www.basf-cc.com, www.guiadeprensa.com/construccion/construcciones-mecanicas-estructuras/entibacion.html and www.manitou.com/es/index.htmlSection 5 Gorostiza-CadaguaThe construction of section 5 Gorostiza-Cadagua, budgeted at EUR90.5 million, has been awarded to Tecsa, Altuna y Uria, Fonorte and Hermanos Elortegi. Visit www.tecsa.es, www.altunayuria.es and www.fonorte.comSection 5 includes the Santa Agueda tunnel. The San Sebastián-Cantabria tube stretches for 1,964 m. The Cantabria-San Sebastián tube is 1,980 m long. Both figures correspond to the mined lengths of the tunnel excavated by means of explosives. Additionally, at each end of every tube there will be cut-and-cover portions (87 metres in the Cantabria-San Sebastián direction and 61 metres in the San Sebastián-Cantabria direction).The typical cross-section will accommodate three lanes, with an outer bored face of 119.8 square metres and an inner finished section of 100.7 square metres, or four lanes with an outer bored cross-section of 173.5 square metres and an inner finished face of 129.9 square metres. On the other hand, the cross-section is different as per each type of support. There will be six 9.4 sq m pedestrian cross-passages and two 24.1 sq m vehicular cross-passages.GeologyThe Gorostiza-Cadagua section crosses a rocky substratum belonging to the Ereza formation constituted mainly of calcareous sandstone, siltstone more or less calcareous, limestone with siliceous cemented ankerite, calcareous and sandy layers and superficial anthropic backfill with elluvial and colluvial deposits.Tunnelling methodThe drill-and-blast method is used. Atlas Copco supplies four Boomer WE 3C drilling rigs equipped with three booms and one basket boom while Maxam is the supplier of the explosives produced in their Galdakao plant in Biscay. Excavation of the tunnels was scheduled to commence on 25th March, 2008. Each tube will be attacked from both ends, which means two drives per tube. Artistic impression of the Santa Agueda tunnel, which will cross Alonsotegi Rock haulageFor mucking-out, a set of a JCB 456E loader, a Volvo A25C truck and a JCB JS175W MON wheeled backhoe loader is employed at each face. Visit www.jcb.co.uk and www.volvo.com/constructionequipmentPrimary support and final liningThe support required is, in some cases, 25 mm-diameter bolts and subsequent shotcreting. In other cases, it is TH-29 steel beams, 15 x 15 x 6 mm welded mesh and Bekaert's Dramix fibre-reinforced shotcrete. The final lining is 30 cm-thick mass concrete produced by Hanson Hispania in their plant in Zaramillo (Biscay). Visit www.hanson.biz/esThe other machinery used on section 5 in each tube includes a BASF's Meyco Potenza shotcreter, a Sika Putzmeister PM-500 concrete pump, a wheeled Manitou MRT 1635 M handler and Zitrón ZVN 1-14-110/4 fans. Visit www.meyco.basf.com, www.putzmeister.es and www.zitron.com The Atlas Copco WE 3C drill rig Section 7 Cadagua-PeñascalSection 7 Cadagua-Peñascal, with a financial envelope of EUR111.9 million, will be constructed by a joint venture formed by Excavaciones Viuda de Sainz, Excavaciones Cantábricas, Obras Subterráneas, Asfaltos Uribe and Ceprenor. Visit www.obrassubterraneas.es, www.asfaltosuribe.com and www.ceprenor.comThis section includes the Arraiz tunnel. The tunnel in the San Sebastián-Cantabria direction is 2,263 m long. The parallel tunnel in the opposite direction is 2,261 m long. These are the figures for the mined lengths of the tunnel excavated by means of explosives. In addition, each end of the tunnel will be built in cut and cover (32 metres on the Cantabria-San Sebastián carriageway and 38 metres in the opposite direction).The short single bored tunnel on the Cadagua junction is 247 m long, with 10 metres cut and covered at the entrance.The typical cross-section will accommodate one, three or four lanes, featuring an outer bored face of 81.7 square metres and inner finished area of 71 square metres for one lane, 119.8 square metres and 100.7 square metres for three lanes, and 173.5 square metres and 129.9 square metres for four lanes. The typical cavern cross-section comprises an outer excavated face of 259.6 square metres and an inner finished face of 179 square metres. Moreover, the cross-section is different for each type of support.Sequential excavation has been started driving the top heading first and benches in a second phase. Each bore is attacked from both ends, which means two faces per tube. Also, six 9.4 sq m pedestrian cross-passages and three 24.1 sq m vehicular ones will connect the twin tunnels together. Excavation proceeds in both directions of the tunnel. As of 10th March, 2008, advance from the Cantabria (Cadagua) side was 70 metres in the Bilbao-Cantabria tunnel and 35 metres in the Cantabria-Bilbao tunnel. From the Bilbao side (Peñascal), progress was 70 metres in the Bilbao-Cantabria tunnel and 75 metres in the Cantabria-Bilbao tunnel. In the tunnel on the Cadagua junction, the advance was 10 metres. Mouth of the Arraiz tunnel GeologyOn section 7 Cadagua-Peñascal, ground investigation identified materials belonging to the Ereza, Arraiz and Tejera formations, the latter being in majority. The bedrock is composed of calcareous sandstone and siltstone more or less calcareous of the Ereza formation, micritic limestone belonging to the Arraiz formation, stratified calcareous sandstone, siltstone more or less calcareous, nodulous limestone and finely laminated siltstone of the Tejera formation and, in the superficial layers, anthropic backfill as well as elluvial and colluvial deposits. Tunnelling methodExcavation is done by means of explosives. From the Cadagua side, three drilling jumbos are used: two Sandvik three-boom DT1130-CDATA and one Atlas Copco two-boom RB282. From the Peñascal side, three Atlas Copco drilling rigs are used (two three-boom XL 3Cs and one two-arm H135). Maxam supplies the explosives produced in their Galdakao factory (Biscay).Other ancillary equipment includes four 132 kW sets of fans T2.160 of Cogemacoustic, three pumps ZH-32/8 from Zeda, two 630 KVA 1K/42K transformers of Inbulnes, two Atlas Copco GA-22 P 500 electric compressor and an Atlas Copco XAS 186 diesel compressor. Visit www.cogemacoustic.com, www.bombaszeda.com and www.inbulnes.comRock haulageFrom Cadagua, two track excavators are used (one Komatsu PC210NLC-8 and one Caterpillar 320), two Volvo loaders (a L150 and a L120), and three articulated dumpers (one Volvo A25 and two Caterpillar 735). From Peñascal, crews are using a Volvo L120F loaders and three articulated dumpers Volvo A25. Visit www.komatsu.com/ce, www.cat.com and www.volvo.com/constructionequipmentPrimary support and final liningThe supports to use include, in some cases, 25 mm-diameter bolts, Minova resin cartridges and subsequent shotcreting. In other cases, it is TH-29 steel beams supplied by Emcor, 15 x 15 x 6 mm welded mesh and shotcreting. The shotcrete produced by Ogerco contains Maccaferri steel fibres and Sika setting accelerator. The final lining is 30 cm thick mass concrete. Visit www.emcorsa.com and www.maccaferri.comAt the Cadagua mouth, two Putzmeister PM-500 shotcreting robots and three Manitou telescopic handlers are employed. At the Peñascal drive, there are two Putzmeister shotcreting robots (a PM-500 and a Wetkret 103) and three Manitou telescopic handlers. A Putzmeister PM-500 shotcreter Section 8a Peñascal-LarraskituUrazca, Construcciones Mariezcurrena, Nortúnel and Asfaltos Olarra are constructing section 8a Peñascal-Larraskitu for EUR88.1 million. Visit www.urazca.com and www.nortunel.comThis section includes the Larraskitu tunnel (831 m long for the Cantabria-Bilbao carriageway and 894 m long for the Bilbao-Cantabria carriageway). Both lengths correspond to the parts of tunnel that are mined by means of explosives. Furthermore, at each mouth there are cut-and-cover portals (75 metres for the Cantabria-Bilbao carriageway and 90 metres for the Bilbao-Cantabria carriageway). Excavation of the face progresses in sequential phase, top heading and benches. The typical cross-section carries two lanes, with an outer excavated area of 106.8 square metres and inner finished area of 88.7 square metres. On the other hand, the cross-section differs according to each type of support.Two 9.4 sq m pedestrian crosscuts connecting the twin tunnels and a 24.1 sq m vehicular one are also planned. It is foreseen to attack each tube for both ends, which means opening two drives per tube. As of 10th March, 2008, excavation of the tunnel on the Bilbao-Cantabria carriageway had begun, from the Cantabrian side. Advance had then reached some 30 metres. Tunnelling was scheduled to commence on the other drives from mid April. The Larraskitu tunnel in the Bilbao-Cantabria direction, Cantabria side GeologyGround surveying along section 8a Peñascal-Larraskitu revealed materials belonging to the Arraiz, Ortuella and Tejera formations, the last one being the main rock mass. These materials are essentially limestone belonging to the Arraiz formation, calcareous sandstone, calcareous siltstone, nodulous limestone and finely laminated siltstone of the Tejera formation, black laminated slightly calcareous siltstone and arenilitic, turbiditic intercalations belonging to the Ortuella formation and anthropic backfill as well as elluvial and colluvial deposits in the superficial layers. Tunnelling methodThe drill-and-blast method is used. Sandvik supplied four tunnelling jumbos, two of which are two-boom Axera T08 S-290C. Explosivos Río Tinto supplies the explosives. Digging started first by using a JCB 260-NC track excavator per drive.Rock haulageFor mucking-out, there is a Caterpillar 938G loader at each portal and two Volvo 250 dumpers. A Caterpillar 938G loader Primary support and final liningSupport consists, in some cases, of bolts with Lokset KP resin cartridges from Minova, welded steel fabric, and subsequent shotcreting with Sika-Putzmeister PM-500 PC shotcreter. In other cases, TH-29 steel arches supplied by ArcelorMittal are used together with shotcrete reinforced with Maccaferri fibres. The concrete admixture is Sika's Sigunita L-26 R. The welded steel fabric and steel arches are placed with a Manitou MRT 1635 telescopic handler. The final lining is 30 cm-thick mass concrete. Visit www.arcelormittal.com 24/08.