附录AEuroPean Tunnelling ReviewQuality，Environment and Safety FocusBill Weburn(Vinci Construction Grands ProjetsF一92851，France)Abstract This paper provides an overview Of tunnelling projects with some of the themes covered by the Chengdu Tunnelling Conference.(a)Environmental issues and tunnels under high groundwaterpressure((Hallandsas Rail Tunnel，Sweden)(b)Fire-fighting and tunnel safety on long highway tunnels(Socatop Tunnel，WestParis)(c)Mechanised tunnelling below the world’s largest airport (HeathrowTS)of aquality that avoids disruption to its operation.Each of these overviews show an enhanced performance in regard to projects specific events or objectives. Particularly，in tunnelling，project owners expect more than just a facility delivered on time for Iheir money: they expect an all roundperformance respecting deadlines，budget，environmental protection，safety，qualily and community harmony. Funding agencies do not always have the same agenda as project owners，acknowledging peripheral selection criteria but often demanding that the lowest bidder be awarded work. All round Performance requires all round project selection criteria.Hallandsas Rail Tunnel，SwedenThe Hallandsas Rail Tunnel is located between Malmo and Gothenburg and is part of the Swedish high speed rail link between the Oresund crossing to Denmark and Oslo.Vinci Construction Grands Projets and Skanska are currently working in a joint venture to complete this tunnel，on which work had stopped during the 1905s, after damage to the environment had been sustained.The idea for a tunnel through the Hallandsas Ridge had first heen reviewed as early as 1975,and by 1988，the Swedish National Railway Administration(“ NRA”)drew up a conceptual design for the tunnel. The Hallandsa ridge is primary horst formation consisting of mainly fractured gneiss partly weathered into clay and amphibolite.It is considerably more aquiferous than most Swedish primary rock formations，which makes the area on the ridge and the Bj re peninsula highly suitable for cultivation.In 1992，the NRA initiated construction with its first contractor who commissioned an open-mode TBM for an unlined tunnel,designed with lateral rock grippers. In mid 1993,it became stuck after advancing 16m, when the machine sank into the machine sank into the highly weathered surrounding ground. Work continued by conventional tunnelling until the end of 1995，when with 3,000 metres bored，the contractor withdrew.By 1996，work recommenced and a central access gallery was exeavated to open four additional tunneling faces using conventional tunnelling methods.High rates of water ingress at 601/ second，instead of the amounts Provided for in the contract at less than 331/second，seeped into the tunnel and hampered progress. This water inflow caused a draw down of the water table locally and dried a number of wells in the vicinity. Over 80 different grouting agents were tested for suitably low enough viscosity to penetrate all fractures，before Rhoca-Gil(bi-component chemical sealing agent) was used.This grout sealing agent polluted the ground water，Poisoned livestock and high levels of acrylamide(toxic additive)were subsequently found in water flowing from the tunnel.This ecological scandal in october 1997 drove the media into a frenzy and，with substantial local stakeholder protest，caused work on the project to be suspended with only 6 000m bored.Decontamination of the tunnel and water table was carried out in 1998-99，by removing active acrylamide and installing a waterproof lining in a re-dimensioned tunnel in zones of high water ingress.Decontomination consisted of draining the groundin grouted areas to try to recover the toxic additive .Tunnel lining had been requested by the NRA over some 750m of each tunnel at the northern section ,which had reduced water ingress to 131/second by March 2000.Less than one year later, the project was to be halted again,since it was recognized that excavation could no longer continue by conventional methods.By early 200l，the railway link between Malm and Gothenburg had been 90% complete with 30 km outstanding，of which 10 km comprised the Hallandsas Rail Tunnel.Despite hostile public opinion，and under intense media and political pressure，the NRA was committed to completing the Project with no further mistakes.Water ingress had been limited to 131/second for the four tubes and the central accesses.Water table levels had been recharged and the site was now pollution free. Completing the ProjectThe Swedish NRA initiated a European tendering process that was won by Skanska-Vinci JV(”JV”) in July 2002.The JV and Herrenknecht developed a mixed shield capable of functioning as a hard rock machine in open mode(anticipated over 80% of the drive)and as a slurry machine in closed mode.The TBM has been designed to operate under 8 bars Pressure and can drive in short lengths at pressures of up to 13 bars.The machine has been custom designed to accommodate 6 drills for probing and ground treatment as follows: ·3 on the back-up，with each having 44 drilling positions，distributed over 360 degrees(30 through the shield and 14 through the cutterhead);·2 Inside the Shield,each with 12 drilling positions through the cutterhead;·1 at the TBM centre，with 6 drilling directlons.However，a specific part of the tunnel，known as the Mollebackzonen，comprised of highly weathered and highly fractured rock，will still need ground treatment prior to the TBM drive.This will require a 20m Pilot gallery to be excavated from the North drive by conventional tunnelling methods and the creation of two small chambers.Thereafter，the ground will be frozen over 100 m in the highly weathered andhighly fractured zone，and then grouted over the further 200m in the highly fractured zone.The TBM will then drive through to complete the full size tunnel.The segmental lining is 54cm thick 2,20m wide and composed of 7 standard segments and 1 key. Segments，are designed to resist 15 bars pressure and rings are fitted with a gasket which will be tested at 45 bar.Enviromental Protection RequirementsIn addition to monitoring and controlling noise，vibration，air quality and waste management，a rigorous and thorough environmental protection programme is now operated，requiring a detailed review and chemical analysis of all products used for the Works. Currently，more than 500 materials submittals sheets have been issued requesting approval of proposed materials.Management of water discharges from the tunnel is now subject to rigorous and continuous control and six environmental engineers are permanently stationed on site.Water inflow from the tunnels is monitored quantitatively and qualitatively twice a week and continuously for discharges.Inflows during construction are specified not to exceed 100/second over 4 week period on average and a maximum of 2801/second daily，A water treatment plant is installed on site to purify wate r．Tunnelling ManagementIn order to respect the maximum water inflows，the JV has developed the following tunnelling strategy:·Probe forward to estimate impending water inflow and to assess the ground;·Carry out ground treatment from the TBM ,if necessary;·Monitor effect by probe drilling;·Drive in open mode if impending water inflow and/or geological conditions are suitable，and otherwise drive in closed mode.It is necessary to bear in mind that payment is made in accordance with specified boring and grouting classes，proposed by the JV for the NRA's agreement，and referred to a technical panel for resolution of Payment class in the event ofdisagreement.Payment classes for boring.EndwordThe Hallandsas Railway Tunnel represents a new challenge in tunnelling at 13 bars and a state-of-the-art TBM is being manufactured by Herrenknecht for this purpose.In addition，a high standard of environmental monitoring and management is being implemented to safeguard local ecology，after a series of infelicitous mishaps during previous development of the Project.The Project is now back on track with tunneling having started in March 2004 and all efforts have been made and precautions taken to make this tunnel operational.A86 Socatop TunnelThe A86 autoroute is a ring-road skirting the Creater Paris region known as the Ile de France. Most of this ring road is in operation，with the remaining uncompleted section hetween Rueil Malmaison and Versailles designed underground in the interests of residential and environmental harmony 。