Flood Relief Tunnel Starts in ParisAn impressive tunnel boring machine commences to work at the Ivry-Massena tunnel (TIMA) in Paris. Its mission is to dig Europe's biggest and deepest rainwater storage tunnel, between the 13th district of Paris (Pont National) and Ivry (Parc des Cormailles). The 1,000-tonne Herrenknecht TBM, assembled in a 35 m-deep shaft, has been christened on Wednesday 17th May, 2006 in the presence of 80 tunnellers and its godmother Catherine. Visit www.herrenknecht.com Thanks to its exceptional diameter, the Ivry-Massena tunnel will have the capacity of holding sewer overflows which cause the run-off of sewers and the discharge of untreated waters into the Seine. The tunnel will be capable of storing up to 80,000 cu m of wastewater, thus avoiding spills along the streets or directly into the river. Once the weather has returned to normal, the waters will be conveyed to the wastewater treatment works in Valenton, upstream the Seine.The 1,860 m tunnel will be driven by an Herrenknecht EPB machine. Its outer diameter is 7.9 m and its inner diameter is 6.8 m. The alignment lies at a depth of 30 metres (under a water load of 25 m) and successively meets sands and plastic clays, then it crosses Montien limestone and then chalk (50% of the ground). The exit shaft is already sunk, as part of a previous contract. The right-of-way is situated at a site on the river bank next to the Seine, on a plot belonging to the Paris autonomous port authority. It has been necessary to install a curtain of steel pipes, 27 m long and 1.2 m of diameter, along the embankment by sheet driving and vibrodriving, then a platform has been built. From there, diaphragm walls have been cast in place to shape two 17.5 m ID 30 m-deep shafts (54 m of walls) and a connecting tunnel and a start tunnel, each of a dozen metres long and approx. 10 m of section, have been bored. These works were performed from July 2004 to March 2006.By June 2007 when the tunnel is commissioned, 'Catherine' - operated by a JV of Bouygues TP (leader), Campenon Bernard TP, Razel and Spie Fondations - will chew its way at the expected daily advance of 15 metres in different geological layers in the Parisian subsoil. Visit www.bouygues-construction.com, www.cbconstruction.fr, www.razel.fr and www.spiefondations.com The TBM previously bored contract 2 on Line B of the Toulouse metro. It has been revamped for the project by the contracting JV assisted by Herrenknecht in a warehouse in Limay. Assembly at the site commenced in April 2006 and is nearing end. Click fr/51.The spoil is removed by a conveyor belt, then it is dumped into a skip which, once filled, is loaded by an overhead crane on a barge that takes it away on the Seine. The lining consists of six 35 cm-thick precast reinforced concrete segments. They will be produced by Stradal and brought to the site on the waterway. The total cost of the project will be around EUR70 million (including technical maintenance of the TBM). Visit www.stradal.frThe scheme is the first component of a network of two tunnels: TIMA 1, just kicked off, and TIMA 2, which will start at the ring road (to Porte de Charenton) to connect with TIMA 1 in the 13th district in Paris (Pont National).Preparatory works are under way prior to excavating TIMA 2. These works entail a launch shaft, connections to Paris combined sewers and technical premises as well as an intermediate shaft with also links to the sewage system and technical facilities. These two shafts, about a dozen metres of diameter and 30 metres deep, will be sunk using diaphragm walls. A 4 m-diameter ID 800 m-long tunnel will lead to one of the TIMA 1 shafts at Pont National.The geology of this tunnel is similar to the upstream part, i.e. TIMA 1. The tunnel should be bored by an Herrenknecht EPB including Eiffage TP (leader) and Urbaine de Travaux. The intermediate shaft will be built by Soletanche Bachy. Read E-News Weekly 50/2005. Visit www.eiffageconstruction.com and www.soletanche-bachy.comFor both tunnels, the owner is SIAAP (the sewage management authority for Greater Paris). SIAAP's department of major projects manages the programme. Visit www.siaap.fr 24/06.