First LIRR's East Side Access TBM Arrived in NYCLong Island Rail Road's East Side access project includes two new tunnels under Manhattan and Queens to connect with the existing 63rd Street tunnel below the East River and enable LIRR to operate trains to Grand Central station. Bringing LIRR trains into Grand Central requires a major Manhattan dig. Trains will travel under the East River through an unused portion of the 63rd Street subway tunnel that links Queens and Manhattan.The bi-level 63rd Street tunnel under the East River was constructed starting in 1969, designed to carry both subway and commuter rail trains. Due to budget shortfalls, the tunnel remained unused until 1989, when F train service was routed through the tunnel's upper level to 63rd Street and Lexington Avenue. An unused area beneath the F tracks under 2nd Avenue will carry the LIRR trains, which will access the tunnel from the Sunnyside station in Queens. The tricky part now is digging the tunnel the rest of the way to Grand Central. The lower level currently terminates at 63rd Street and 2nd Avenue, where the TBM will pick up shortly to begin boring toward Grand Central. Manhattan tunnelsEssentially, this project consists of two parts, the Manhattan tunnels and the Queens tunnels, which will connect via a pre-existing submersible tube (the 63rd Street tunnel, which was partially excavated in the 1970s and cancelled due to lack of funding). Contracts have not been awarded yet for the Queens tunnels.The Manhattan tunnel is a twin-bored two-deck tunnel of 7,681 metres. The bored diameter is 6.70 metres (22 feet) and the lined diameter will be 6.2 metres. The project includes two tunnels for trains travelling in both east and westbound directions. Both of the Manhattan tunnels will be excavated directly under major structures in New York City including Park Avenue and Metro North rail lines. As they approach Grand Central station, the Manhattan tunnels will bifurcate to form four tunnels.The contract CM009 for the Manhattan tunnels (both eastbound and westbound) was awarded in 2006 to Dragados and Judlau Contracting. Click here & us/18. Visit www.mta.info/capconstr/esas/index.html and www.dragados-usa.comOther underground facilitiesOther underground structure include:- GCT-3 tunnels (east and west) in Grand Central Terminal, with variable cross-section starting with 6.70 metres and gradually widening to 18.9 metres. This tunnel will serve for future extensions under Grand Central.- GCT-5 tunnels (east and west) in Grand Central Terminal, with variable cross-section starting with 6.70 metres and gradually widening to 16.8 metres. This tunnel separates the upper and lower levels.- 8.5 m (28 feet) wide x 4.3 m (14 feet) high installation chamber.- nine horseshoe-shaped connecting tunnels, 3.66 m x 3.66 m (12 x 12 feet).There are no intermediate station nor access to the surface in contract CM009.Connecting tunnels under future contracts will be completed in Queens to link the Manhattan tunnel to the LIRR's main line and Port Washington branch tracks. They will require soft ground excavation techniques using earth pressure balance machines. Ultimately, two underground chambers with upper and lower levels will be excavated underneath Grand Central station for commuters to travel on the new rail lines. The stations, which are 18 m-wide x 18 m-high x 122 m-long chambers, will be excavated using drill and blast techniques in gneiss and granite geology. In 2006, the Queens shaft was widened to about 61 metres across at its widest point, resulting in a "bellmouth" that will be used to transport of hard rock TBM components into the 63rd Street tunnel for final assembly. The cavernous hole deep under East 63rd Street was recently blasted open, leaving just enough room to fit the first TBM that will dig 15 metres a day through Manhattan bedrock all the way to Grand Central. The work was the first big step in LIRR's East Side access.GeologyRock in the Manhattan tunnels was determined to be a combination of schist, gneiss and granite, with a UCS of 80-200 MPa and two fault lines. The rocks of Manhattan have a complex structural history due to several superposed phases of deformation. They have created an intensely folded and locally sheared rock mass with penetrative fabric, total recrystallization and localized partial melting of the rocks. The most prominent fold phase consists of asymmetrical and associated folds that define the regional structure of Manhattan.The discontinuities in the rock mass are the metamorphic fabric and joints caused by tectonic activity and granitization. The foliation, foliation discontinuities, and other discontinuities exhibit a wide range of spacing values that is typical of this rock which has undergone major tectonic episodes such as folding, faulting and intrusions. The existence of four dominant joint sets for the rock mass at the project site have been confirmed by geological mapping of the exposed rock and oriented core borings.Construction methodsDrilling and blasting is used to build the shafts and stations whereas the tunnels will be TBM-driven and lined by a final in-situ concrete formwork process. The machinery used by crews include two cranes, one of 200 tonnes and one of 45 tonnes, a Sandvik Tamrock two-boom jumbo, six 35-tonne locomotives, four 7.6 cu m muck wagons and four 15.2 cu m wagons, ten 9.1 m 15-tonne platform wagons, two Wagner low profile loaders (models ST 5 and ST 3.5), two shotcreting systems (one dry- and one wet-mix process), three elevating platforms, two TBMs, and vertical and horizontal conveyor belts spanning an overall length of 7,315 metres (24,000 feet). Visit www.sandviktamrock.fiTwo TBMsFor the Manhattan tunnels, there will be two TBMs, both the same diameter, and four drives. This is not determined for the Queens tunnels. The eastbound tunnel will use a double shield TBM rebuilt by SELI, while the westbound tunnel will use a 6.7 m-diameter Robbins main beam TBM. Both TBMs are originally Robbins but SELI has the contract for the eastbound tunnel and Robbins has the contract for the westbound tunnel. Robbins will also supply a back up system and spare parts for the westbound tunnel, as well as continuous conveyors and complete muck hauling systems for both tunnels. Visit www.therobbinscompany.com and www.selitunnel.com or www.selitecnologie.comThe 7.92 m x 7.92 m x 22.5 m assembly chamber for the SELI TBM has been drilled and blasted under 63rd Street and 2nd Avenue. Once assembled, the machine will excavate the upper east tunnel and when it reaches the end of the upper level, it will be dismantled and re-assembled in the east GCT-5 tunnel. Once re-assembled in that tunnel, the machine will bore the lower level. The SELI TBM is a revamped double shield dressed with 37 48.3 cm (19 inch) disc cutters and four 43.2 cm (17 inch) double cutters. The initial cutters are supplied by Palmieri whilst Herrenknecht supplies the spares. Visit www.palmierirocktools.com and www.herrenknecht.comThe 7.31 m x 7.31 m x 21.3 m assembly chamber for the Robbins TBM is drilled and blasted under 63rd Street and 2nd Avenue. Once assembled, the machine will excavate the upper west tunnel. When it arrives at the end of the upper level, the machine will be pulled apart and re-assembled in the west GCT-5 tunnel. Once ready in that tunnel, it will excavate the lower level. The Robbins TBM is a revamped open TBM equipped with 34 48.3 cm (19 inch) disc cutters and four 43.2 cm (17 inch) double cutters. Robbins has the cutter contract for the wesbound tunnel.The first, USD10 million SELI tunnel boring machine's largest components arrived via ship in Red Hook, New York, on 19th May and trailing gear and smaller components were scheduled to arrive soon after. After US customs clearance, the pieces were expected to be taken to Long Island City, where workers will lower the components into the 63rd Street tunnel and transport them under the East River to a 19.8 m launch box under 63rd Street and 2nd Avenue. The 200-tonne machine will take two or three months to assemble in the launch box and begin digging its way toward Grand Central Terminal around September. The second, Robbins tunnel boring machine is scheduled to be delivered later this year to dig a second tunnel. The westbound TBM must be able to retract through the varying cross sections of tunnel to bore the tunnel fork into Grand Central station. The machine will include a segmented, bolt-only cutter head, and hydraulic extensions of the vertical front support and roof support structures, as well as the side support structures. The hydraulic extensions will allow the diameter of the TBM to expand and retract as needed for swift transport in the varying cross sections, even if steel ring beams are in place. These expandable components allow the TBM to fluctuate from a 6.136 m diameter when fully retracted to 6.906 m when fully extended. Retraction after the TBM has bored its first length of 2,200 metres will involve high-capacity transport dollies, which will lift the nearly fully assembled TBM and transport it back through the freshly bored tunnel after removal of the outer cutter head, ring beam erector and roof shield fingers. The TBM will then be re-launched from the assembly chamber, approximately 305 metres away from the first bore.Both hard rock TBMs will be partially assembled at the bottom of the 23 m-deep Queens shaft, then transported through the submersible tube and 2,650 metres of pre-existing tunnel for final assembly beneath Manhattan. The westbound TBM will be assembled in a very compact, 6.7 m-diameter, 19.8 m-long assembly chamber that will be excavated by drill and blast before the TBM arrives. The chamber must be kept compact to minimize drill and blast development work, as there is an existing rail tunnel directly overhead.Primary rock support will consist of rock bolts, channels, and steel ribs in some areas. Final tunnel lining will consist of a PVC waterproofing membrane and waterproof cast in place concrete lining using steel formwork carriages.Mucking-outRobbins will supply continuous conveyors for both tunnels that will transport muck across busy roadways for storage in the Sunnyside rail yard approximately 366 metres from the jobsite. Two fabric conveyors (914 mm in width) will travel behind each TBM operating in the eastbound and westbound tunnels, and will dump into a single fixed length conveyor via a cross conveyor. In existing tunnel sections, the tunnel conveyors will be fitted with special floor stands to support the side-mounted conveyors on a horizontal floor rather than a circular one. Muck will be transported up the 23 m shaft using a fixed length, steel cable vertical conveyor. Once the muck has reached the top of the shaft, it will be transported to the rail yard using three overland conveyors and a radial stacker. The second overland conveyor, 37 m long, will cross Northern Boulevard, a major thoroughfare in Queens. This conveyor will be designed as a totally enclosed box truss with 152 mm-wide flange beams at all four corners which will support it approximately six metres above the roadway and under pre-existing MTA rail lines. The truss will discharge onto another overland conveyor, which will take the muck to aradial stacker conveyor in the Sunnyside rail yard. This conveyor will rotate through 60 degrees to deposit muck in kidney-shaped piles with a capacity of 8,400 cubic metres.Behind each TBM, an independent conveyor belt system will extend as the TBM progresses and the two belts will join in York Avenue. From York Avenue, a unique belt will transport the excavated rock - the one in the existing east tunnel. When the material arrives at the existing start shaft, a vertical belt will take over and an elevated belt in Northern Boulevard will pour the material in the designated area. Once stored, the rock will be trucked to the final dump site.To evacuate the rock excavated by means of the drill/blast method, low profile loaders and muck trains will be used.The railway equipment is not part of the contract. The Dragados/Judlau JV will install only the ventilation, lighting and water drainage required during construction. 24/07.