TBMs Ready for Rome Metro LinesLine B1 is the first line where work commenced in October 2005. Then, construction sites for Line C have been prepared at different places throughout the city. For the time being, this refers solely to the archaeological digs and the construction of stations but within a few months, the TBMs should start digging the tunnels. The less advanced Line D, on the contrary, is still on the drawing board. The Ministry for infrastructure allocated the City of Rome EUR500 million to build Line C. This financing will be spent on the construction of the central section from San Giovanni to Clodio. Line B1At a workshop acceptance in Herrenknecht's facilities, SELI received the first EPB TBM that will excavate the twin tunnels of Line B1, from Jonio Esplanade to Bologna Square. The second TBM is also to be delivered. It will bore one of the twin tunnels from a shaft at Conca d'Oro station towards Bologna Square, after a long and complex assembly phase within the shaft in the first months of 2008. The TBM start is programmed within the summer, ahead of the schedule first anticipated, and the machine will bore at a depth of 30 metres under Valli bridge, the Aniene river, Libia Blvd, Eritrea Blvd and the district located between XXI Aprile Blvd and the ring road. The TBM will work 24 hours under an hydrostatic head of five metres. Shifts of 12 specialised workers will operate the machine. Visit www.herrenknecht.comOnce the friability problems of the ground are resolved next spring, the TBM will be able to enter in action to excavate the tunnel between the stations. Three TBMs will be working in Conca d'Oro alone, two towards Bologna Square and one to Jonio Esplanade.The bored diameter will be 6.80 m whilst the inner diameter, after placement of the segments, will be 5.80 m. The thickness of the concrete lining, formed by six precast segments and the key segment, equals 35 cm. The expected geology is a sedimentary complex of the Paleo-Tiber 2 (fluvial, paludal and lacustrine sediments) composed of silty sands, silty clay, clayey silts and sandy silts. The mucky equipment will be locos and muck wagons. The project was put out to tender inviting private contractors to bid for both the final design and construction. The successful bidder has been a consortium named Risalto (the first syllables of the three contractors Rizzani de Eccher, Salini and Todini), leader of the joint venture, with Maire Engineering, Maire Lavori, ICOP and TPM Trivel Pali Mediterranea. The three partners within Risalto later decided to dissolve the consortium and to split the different contracts they had successfully pocketed together. The Line B1 contract went to Salini. Tunnelling has been subcontracted to SELI for EUR42.2 million. Visit www.selitunnel.com, www.salini.it, www.maireengineering.it, www.icop.it and www.tecnopalimediterranea.itProject alterationsOn 20th October, 2007, Walter Veltroni, who recently stepped down as the mayor of Rome ahead of national general elections in April, announced that Line B1 would be extended a further 1.1 km up to Jonio Esplanade, where the line will intersect with the future Line D Agricoltura-Ojetti. This is to make up for the decision to cancel the construction of Nomentana station, which officials decided not to build due to problems related to the nature of the subsoil. Had the station been built, these problems would have inflated the construction bill, estimated at EUR520 million so far, and delayed the time schedule, estimated at 62 months, by about a year and a half. In principle, from north to south, the stations were supposed to be named Conca d'Oro, Libia/Gondar, Annibaliano, Nomentana and Bologna (the latter connecting with Line B). According to the project alterations, the line terminus will no longer be located in Conca d'Oro but in Piazzale Jonio and there still will be four stations (Annibaliano, Libia/Gondar, Conca d'Oro and Jonio). The line will stretch fully underground for 5 km instead of 3.9 km. The line will therefore serve a very wide area in the northeast borough of Rome, covering populous areas such as Valmelaina and Tufello. The added stretch will also be completed in April 2011. Visit www.youtube.com/watch?v=7m1jAXIfmZI To build the line, the city of Rome has earmarked EUR75 million. This additional financing is a green light for Roma Metropolitane to review the feasibility and subsequent design of the new stretch and the structure planned in the changes to the initial project. The location of the ex Nomentana station will be connected by travelator with the station in Piazza Annibaliano. It is a 400 m subterranean pedestrian link which will take three minutes to walk. Work under wayThe construction of the stations on Line B1 is well advanced but limited to the creation of the station boxes. At Conca d'Oro station, jet grouting to create fortified or strengthened ground in the central area is still ongoing and the reinforcement works on the Jonio side have now ended. At Libia/Gondar station, the jet grouting process is being used to provide permanent foundation support and the slab at street level is under way at Palombara Sabina Square.At Annibaliano station, jet grouting reinforcement and the cover slab are also under build. Excavation of the first level of the station is proceeding under the slab.Jet grouting reinforcement is making headway at the XXI Aprile Blvd. shaft. Ventilation shafts on the Conca d'Oro-Libia/Gondar section at the car park of the Nomentana railway station and in Santa Emerenziana Square are being built. All buildings are being monitored in the neighbouring areas to the sites.A peculiarity of the ground investigation campaign carried out in the planning phase has been the opening of an experimental area, consisting of a shaft and test pilot tunnel in Annibaliano Square, to provide a precious source of technical information to planners. In addition, archeological probes have been performed at all the sites signalled by the competent administration.In-depth core drillings have been conducted along the tunnel route (ground samples have been taken from 160 bore holes samples, representing about 4,500 metres of drills) and tests have even been performed directly on the spot and in laboratory to study the groundwater and gather complete data about the geology of the subsoil concerned by the excavation. Before the start of excavation, further ground investigation surveys will be carried out to prevent any interference of the tunnels with possible underground cavities. Click it/31. Read E-News Weekly 18/2002. Visit www.romametropolitane.it Line CThe first of the four tunnel boring machines that will commence next spring boring the tunnels for Line C has been delivered on schedule to the general contractor this winter. To produce a TBM, ten months are necessary.The first TBM, christened Shira, has a 6.71 m-diameter cutter head, is about 100 m long and weighs 750 tonnes. It is powered by 3,000 kW. After testing last 13th December in the premises of Herrenknecht, the TBM was disassembled and transported to Rome in February by 30 trucks. The part will be lowered in the purposedly built shaft in advanced construction stage near the future Giardinetti-Torrenova station. This is where the final assembly of the first TBM will take place, which will last at least two months. The machine will dig towards Alessandrino at a depth of 30 metres. Tunnelling will constantly be monitored to keep under control the possible effects on the foundations of the neighbouring buildings. At the corners of the buildings within the excavation area, electronic inclinometers will be installed to warn in real time of any settlement, even insignificant.The TBM will progress at about 8-12 metres each day with peaks at 20 metres and it can work 24 hours a day, seven days a week. As it moves forward into the ground, the machine erects a precast segmental lining to shape a tunnel ready to be equipped with the tracks and the indispensable technological installations for the control and management of the subway. Each TBM will be operated by crews of some 15 tunnellers assisted by 10 other people at the surface for every shift. Click here, here & it/14. Read E-News Weekly 45/2004, 34/2003 & 25/2002.Work under wayRegarding civil works of sections T4-5 of Line C, from San Giovanni to Alessandrino, the relocation of a sewer at Carducci School is almost completed as is the relocation, from Monza Street to Appio Square, of an important pipeline interfering with the future location of the station. The relocation of the telephone cables in Castrense Blvd. and La Spezia Street is also nearing completion.At Lodi in La Spezia Street, the construction of large diameter piles for the adits is under way, and the construction of micropiles in front of the buildings is continuing, prior to the deviation of an important wastewater line which interferes with the station's main structure.At Pigneto, diaphragm wall work for the station is under way.At Malatesta, the first phase of the diaphragm wall supported station box is almost completed. In the area of Portici Street in Malatesta where is the launch shaft of the TBMs that will bore the tunnels to San Giovanni, the construction of the diaphragm walls of the tunnel mouth perimeter is nearing end and the precast cover slab of part of the start box is going to be installed.At Teano, the sinking of diaphragm walls for the line leg to Ponte Mammolo is proceeding. At Gardenie, crews are constructing the station walls and the resurfacing of a road section next to the job site is under way.At Mirto, the large diameter piles for the adits and the diaphragm wall of the station box are nearly completed. The relocation of a deep sewer adjacent to Oviesse is making headway.At Parco di Centocelle, in the area of the Rome-Pantano railway yard at Centocelle, excavation is ongoing to build the access ramps from Casilina Street. Lastly, at Alessandrino, utility line relocation is continuing. Remains uncoveredArcheologists digs are under way in Risorgimento Square, Chiesa Nuova Square, Venezia Square, Madonna di Loreto Square and Santi Apostoli Square.A sixth century copper factory, medieval kitchens still stocked with pots and pans, and remains of Renaissance palaces are among the finds unveiled on 7th March by archaeologists digging up the city in preparation for the new subway line. Archaeologists have been probing the depths of the Eternal City at 38 digs, many of which are near famous monuments or on key thoroughfares. Over the last nine months, remains - including Roman taverns and 16th century palace foundations - have turned up at the central Venezia Square and near the ancient Forum where works are paving the way for one of the 30 stations of the line.The medieval and Renaissance finds that were brought to light in Venezia Square are extremely important for their rarity. Among the most significant discoveries in a ninth century kitchen were three pots that were used to heat sauce. Only two others had been found previously in Italy. The copper factory was used to work on copper alloys, and it consisted of small ovens, traces of which can be seen. Small copper ingots were found and are being analysed. Archaeologists work in an archaeological dig in Rome's central Venezia Square, with the Monument to the Unknown Soldier in the background. The archaeological investigations are needed only for stairwells and air ducts, as the 24 kilometres of stations and tunnels will be dug at a depth of 24 to 30 metres, below the level of any past human habitation. However, most of the digs still have to reach the earth strata that dates back to Roman times, where plenty of surprises may be waiting. That may create problems between planners and conservationists.Under Italy's strict conservation laws, it will be up to Rome's archaeological superintendent's office to decide whether a find will be removed, destroyed or encased within the subway's structures. Countless public and private works have been scrapped over the years in Rome and across Italy, and it is not uncommon for developers to fail to report a find and plow through ancient treasures. Read E-News Weekly 7/2007. To know more about the archaeological aspects of Line C, visit www.archeorm.arti.beniculturali.it 11/08.