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News Article | February 15, 2017
Site: cerncourier.com

Completion of the preliminary design phase for the High-Luminosity LHC last year paves the way for civil-engineering work to begin. Le HL-LHC sera composé de plusieurs technologies et aimants innovants, et ces nouveaux éléments de l’accélérateur auront besoin de services supplémentaires tels que transmission de courant, distribution électrique, refroidissement, ventilation et cryogénie. Afin d’héberger les nouvelles infrastructures et les nouveaux éléments, des structures de génie civil, notamment des bâtiments, des puits, des cavernes et des galeries souterraines sont nécessaires. L’achèvement, l’année passée, de la phase de conception préliminaire du HL-LHC a permis le commencement des travaux de génie civil, et des contrats avec des entreprises externes vont à présent être conclus. The High-Luminosity LHC (HL-LHC) project at CERN is a major upgrade that will extend the LHC’s discovery potential significantly. Approved in June 2014 and due to enter operation in the mid-2020s, the HL-LHC will increase the LHC’s integrated luminosity by a factor 10 beyond its original design value. The complex upgrade, which must be implemented with minimal disruption to LHC operations, demands careful study and will take a decade to achieve. The HL-LHC relies on several innovative and challenging technologies, in particular: new superconducting dipole magnets with a field of 11 T; highly compact and ultra-precise superconducting “crab” cavities to rotate the beams at the collision points and thus compensate for the larger beam crossing angle; beam-separation and recombination superconducting dipole magnets; beam-focusing superconducting quadrupole magnets; and 80 m-long high-power superconducting links with zero energy dissipation. These new LHC accelerator components will be mostly integrated at Point 1 and Point 5 of the ring where the two general-purpose detectors ATLAS and CMS are located (see diagram). The new infrastructure and services consist mainly of power transmission, electrical distribution, cooling, ventilation, cryogenics, power converters for superconducting magnets and inductive output tubes for superconducting RF cavities. To house these large elements, civil-engineering structures including buildings, shafts, caverns and underground galleries are required. The definition of the civil engineering for the HL-LHC began in 2015. Last year, the completion of a concept study allowed CERN to issue a call for tender for two civil-engineering consultant contracts, which were adjudicated in June 2016. These consultants are in charge of the preliminary, tender and construction design phases of the civil-engineering work, in addition to managing the construction and defect-liability phase. At Point 1, which is located in Switzerland just across from the main CERN entrance, the consultant contract involves a consortium of three companies: SETEC TPI (France), which is the consortium leader, together with CSD Engineers (Switzerland) and Rocksoil (Italy). A similar consortium has been appointed at Point 5, in France. Here, the consultant contract is shared between consortium-leader Lombardi (Switzerland), Artelia (France) and Pini Swiss (Switzerland). In November 2016, the two consultant consortia completed the preliminary design phase including cost and construction-schedule estimates for the civil-engineering work. In parallel with the preliminary design, and with the help of external architects, CERN has submitted building-permit applications to the Swiss and French authorities with a view to start construction work by mid-2018. CERN has also performed geotechnical investigations to better understand the underground conditions (which consist of glacial moraines overlying a local type of soft rock called molasse), and has placed a contract with independent engineers ARUP (UK) and Geoconsult (Austria). These companies will confirm that the consultant designs have been performed with the appropriate skill, care and diligence in accordance with applicable standards. In addition, a panel comprising lawyers, architects and civil engineers is in place to resolve any disputes between parties. At ground level, the HL-LHC civil engineering consists of five buildings at each of the two LHC points, technical galleries, access roads, concrete slabs and landscaping. At each point, the total surface corresponds to about 20,000 m2 including 3300 m2 of buildings. A cluster of three buildings is located at the head of the shaft and will house the helium-refrigerator cold box (SD building, see images above), water-cooling and ventilation units (SU building) and also the main electrical distribution for high and low voltage (SE building). Completing the inventory at each point are two stand-alone buildings that will house the primary water-cooling towers (SF building) and the warm compressor station of the helium refrigerator (SHM building). Buildings housing noisy equipment (SU, SF, SHM) will be constructed with noise-insulating concrete walls and roofs. In terms of underground structures, the civil-engineering work consists of a shaft, a service cavern, galleries and vertical cores (see image above left). The total volume to be excavated is around 50,000 m3 per point. The PM shaft (measuring 9.7 m in diameter and 70–80 m deep) will house a secured access lift and staircase as well as the associated services. The service cavern (US/UW, measuring 16 m in diameter and 45 m long) will house cooling and ventilation units, a cryogenic box, an electrical safe room and electrical transformers. The UR gallery (5.8 m diameter, 300 m long) will house the power converters and electrical feed boxes for the superconducting magnets as well as cryogenic and service distribution. Two transverse UA galleries (6.2 m diameter, 50 m long) will house the RF equipment for the powering and controls of the superconducting crab cavities. At the end of the UA galleries, evacuation galleries (UPR) are required for personnel emergency exits. Two transversal UL galleries (3 m diameter, 40 m long) will house the superconducting links to power the magnets and cryogenic distribution system. Finally, the HL-LHC underground galleries are connected to the LHC tunnel via 16 vertical cores measuring 1 m in diameter and approximately 7 m long. The next important milestone will be the adjudication in March 2018 of the two contracts (one per point) for the civil-engineering construction work. In December 2016, CERN launched a market survey for the construction tender, which will be followed by invitations to tender to qualified firms by June 2017. The main excavation work, which may generate harmful vibrations for the LHC accelerator performance, must be performed during the second long shutdown of the LHC accelerator scheduled for 2019–2020. Handover of the final building is scheduled by the end of 2022, while the vertical cores connecting the HL-LHC galleries to the LHC tunnel will be constructed at the start of the third LHC long shutdown beginning in 2024. Realising the HL-LHC is a major challenge that involves more than 25 institutes from 12 countries, and in addition to civil-engineering work it demands several cutting-edge magnet and other accelerator technologies. The project is the highest priority in the European Strategy for Particle Physics, and will ensure a rich physics programme at the high-energy frontier into the 2030s.


Pre M.,SETEC TPI | Thibault J.F.,EIFFAGE TP | Bourget A.P.F.,EGIS Tunnels | Russo M.,BG Consulting Engineers | And 3 more authors.
Underground - The Way to the Future: Proceedings of the World Tunnel Congress, WTC 2013 | Year: 2013

In 2010, due to concerns relating to recent evolutions in contractual practices, the AFTES Technical Committee reactivated the Working Group (GT-25) with the objective to establish guidelines for identifying the "best contractual framework" to meet Owners, Engineers and Contractors expectations of well-balanced contracts, in a "winner-winner" approach in a French legal context, based upon a benchmark of foreign and French experiences. Recently, in France, a number of innovative contracts were experienced in the field of tunnelling activity (Design & Build, advance bid procedures). In parallel, the approach to risk management have developed and a new guideline is now in force (AFTES GT-32 "characterization of geotechnical uncertainties and risks for underground projects") and the French Public Authority included a risk management plan as a compulsory part of the tender documents. This paper presents the initial draft conclusions of this Working Group, including recommendations with regards to the Owner's relation with his Engineer and his Contractor and different contractual arrangements, assessment of risks categories to be addressed to avoid unclear share of responsibilities, recommendations with respect to change management during the works. © 2013 Taylor & Francis Group.


Chanonier C.,Diades | Raulet C.,Diades | Martin F.,LERM | Carde C.,LERM | Resplendino J.,Setec TPI
Beton- und Stahlbetonbau | Year: 2015

Als Teil der Wiederinbetriebnahme der PL1-Pipeline, die Raffinerien und petrochemische Standorte auf der Achse Fos-Lyon-Karlsruhe versorgt, wurden im Rahmen des sog. DIADES-Projekts Untersuchungen im Zusammenhang mit der Verstärkung, Instandsetzung sowie der Erdbebensicherheit einer Fußgängerbrücke durchgeführt, die die Überquerung der Flussaue der Durance ermöglicht. Die Brücke liegt südlich von Avignon und besteht aus acht vorgespannten Abschnitten mit einer Gesamtlänge von etwa 300 Metern. Das Hauptziel des Projekts war die Neubewertung der Erdbebengefahr unter besonderer Berücksichtigung neuerer französischer Vorschriften sowie die entsprechende Ertüchtigung des Bauwerks. Hierzu wurde eine neuartige Kopplung entwickelt, mithilfe derer die Instandsetzung durchgeführt werden konnte. Der vorliegende Beitrag fasst die erfolgreiche Umsetzung der Maßnahme zusammen. Southern Europe Pipeline: new life of a 1960s pipeline As part of the re-commissioning of the PL1 pipeline that supplies refineries and petrochemical sites on the Fos-Lyon-Karlsruhe axis, DIADES project managed, on behalf of SPSE, the studies into and the works relating to the reinforcement /rehabilitation and seismic compliance of a footbridge permitting the aerial crossing of the floodplain of the Durance. This study is based on the structural diagnosis performed by the laboratory of the LERM. This bridge, located south of Avignon, is a structure of eight prestressed isostatic spans with a total length of about 300 m. The main objectives of this project included its capacity to respect seismic compliance, taking into account the re-evaluation of seismic hazard in France. This work was carried out through a fully removable additional prestressed coupling to ensure the heavy maintenance of the pipeline. Using an original example of design and execution to make it possible to sustain the structure during the seismic compliance works, this presentation shows the value of the additional prestressing in the rehabilitation of existing structures, by emphasizing the importance of the diagnosis phase, focusing on the existing prestressing. It emphasizes the reliability of the various assumptions which are helpful for reinforcement dimensioning; these assumptions are based on the results of the pathological analysis of the structure including various structural investigations and inspections. Copyright © 2015 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.


Resplendino J.,SETEC TPI | Toutlemonde F.,French Public Works Research Institute
Indian Concrete Journal | Year: 2014

This chapter summarizes the development of UHPFRC knowledge and techniques until revision of the AFGC recommendations in 2013, emphasizing the evolutions which benefit from building and design feedback and from research efforts made on the last decade. Recent projects and achievements allow emphasizing the specific points of the design which justified the use of UHPFRC and the critical points of the execution which pass the field of traditional structures. Early researches on UHPFRC were made by Professor Bache in 1970 in Denmark under the development of CRC technology. This technology is still very active. In this technology, which a large percentage of metal fiber implemented in a cement matrix to produce prefabricated building structures (balconies, staircases) which are reinforced by traditional reinforcement calculated without taking into account the participation of mechanical fibers.


Cuccaroni A.,Reseau Ferre de France RFF | Veyron P.L.,Setec TPI | Lacroix A.,Spie Batignolles TPCI | Russo M.,BG Consulting Engineers
Underground - The Way to the Future: Proceedings of the World Tunnel Congress, WTC 2013 | Year: 2013

Eastern European High Speed Railway Line Phase 2, linking Paris to Strasbourg includes the Saverne tunnel. In the first design phase, the tunnel was designed as a one double-track tube. Due to financial reasons, only the first section of the line was built. In 2008, RFF decided to build the last part. In 8 years, the design approach to tunnel safety has dramatically evolved. Thus RFF reviewed the whole detailed design including the last safety design regulations. The new study held by Setec outlined that two technical options for tunnelling were equally advantageous in terms of costs and planning. RFF decided to launch a Design and Build (D&B) procedure, a specific contractual form in France. The main reason pushing RFF to choose this procurement procedure was to involve the contractors since the design stage, hence developing the most efficient methodology for tunnel construction with considerations to the Contractor's own expertise and techniques. In 2010, the contract was awarded to a Joint Venture (JV) led by Vinci with the support of BG. This article explains the reasons yielding to choose a D&B contract and what needed to be explicitly defined in the tender documents. Moreover, it gives a first feedback of the construction in development. © 2013 Taylor & Francis Group.


Lanquette F.,Setec TPI
Assessment, Upgrading and Refurbishment of Infrastructures | Year: 2013

A number of beams (out of a total of 120) of the access bridges of the Saint-Nazaire - Saint-Brévin Bridge had some defaults affecting the prestress tendons of the precast concrete beams. Consequently, the owner decided, in addition to a detailed investigation of the beams, to reinforce the South access decks, from the abutment to the main bridge, which is a steel cable stayed-bridge. The aim of the reinforcement was to increase the prestress and to confer more ductility to the beams. The chosen solution consisted in reinforcing the beams with reinforced concrete cast on the lower part of existing beams. A comprehensive study of the influence of prestress tendon failure was made, modeling failures at various positions and taking into account an increasing number of broken tendons. Moreover, this study showed the underlying lack of resistance of the beams with regards to shear stress, shear stress reinforcement was thus designed using carbon fibers. The finite-element software Pythagore developed by Setec tpi allowed us to construct an original model composed of beam and slab elements. With this model a non-linear analysis was performed simulating the deterioration of prestress, progressively deactivating parts of the tendons.


Ferradi M.K.,SETEC TPI | Cespedes X.,SETEC TPI | Arquier M.,SETEC TPI
Engineering Structures | Year: 2013

In this paper, a new beam finite element is presented, with an accurate representation of normal stresses caused by " shear lag" or restrained torsion. This is achieved using an enriched kinematics, representing cross-section warping as the superposition of " warping modes" Detailed definitions and computational methods are given for these associated " warping functions" The exact solution of the equilibrium equations is given for a user-defined number of warping modes, though elastic results are totally mesh-independent. © 2012 Elsevier Ltd.

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