| Session: | LHC 4 |
| Chairman: | Léo Symons |
| Secretary: | Katy Foraz |
| Duration of session : | 90 min. (presentations 60 min., discussions 30 min.) |
| LHC Power Distribution |
| Abstract
The power distribution for the LHC machine and its experiments will be realised making extensive use of the existing infrastructure for the LEP. The overall power requirement is approximately the same, about 125 MW. The load distribution will however change. The even points will loose in importance and the points 1 and 5 will, due to the installation of ATLAS and CMS, gain. A thorough reorganisation of the 18 kV distribution will thus be necessary. Due to the important cryogenic installations required for the LHC, the 3.3 kV distribution system, supplying mainly cryogenic compressors, will be extended with a number of new substations. The important number of new surface buildings, underground caverns and other underground structures all will receive general service installations: Lighting and power. The new injection tunnels will require complete installations: A.C. supplies for the power converters and for general service, and D.C. cabling for the magnets of the beam line. Special safe power installations are required for both certain machine systems and for the experiments. The D.C. cabling of the machine will require a new approach to water cooled cable installations. |
| Contract Management of LHC Civil Engineering at Point 5 |
| Abstract
Civil engineering work commenced in August 1998 at LEP Point 5 for the underground and surface works necessary to accommodate the CMS detector for the LHC project. The principal underground works consist of two parallel caverns, separated by a support pillar, two new shafts, a number of smaller connection and service galleries and tunnel enlargements on the existing LEP tunnel. The surface works consist of the 140 m long SX building for the detector assembly and numerous other steel and concrete structures necessary for the installation and operation of CMS. The civil engineering design and supervision has been awarded to a joint venture of Gibb (UK), SGI (Switzerland) and Geoconsult (Austria), and the contracting to a joint venture of Dragados (Spain) and Seli (Italy) for 112 MCHF. The aim of this paper is to discuss the management of this contract and in particular how the various parties interact in order to work most efficiently. |
| Civil Engineering Construction of Underground Works |
| Abstract
For the first time at CERN, new shafts and caverns will be excavated inside a surface building. The LHC civil engineering construction for the ATLAS experiment has been designed such that the experimental hall will be completed to the extent that it can provide a secure, weatherproof and sound insulated covering to the shaft excavation area. The construction of the two access shafts and the experimental cavern will follow and will be carried out inside the building. This unconventional method of working allows the excavation of the Molasse rock in the dry, which is essential for this type of rock, and ensures reduced environmental pollution by noise and dust. The paper will present the technical infrastructure required for this particular construction method, explain its advantages and disadvantages, and compare it with a conventional method of underground excavations to be used on the same work site for the construction of the service cavern. |
| Projet Neutrino-Gran Sasso Génie Civil |
| Abstract
Le génie civil du projet Neutrino – Gran Sasso est présenté. A partir de protons de 400 GeV/c provenant du Super Proton Synchrotron (SPS) un faisceau de neutrinos est produit et dirigé vers le laboratoire souterrain Gran Sasso, en Italie, à 732 km du CERN. Les ouvrages de génie civil destinés à contenir les équipements de production du faisceau, les méthodes d’exécution, le planning et le budget sont décrits. La procédure retenue pour réaliser le predimensionnement des ouvrages, la préparation du dossier d’appel d’offres et les études d’exécution, est analysée. Le prédimensionnement des ouvrages a été déterminé par le Groupe Génie Civil du CERN et la préparation du dossier d’appel d’offres a été menée par un Consortium de deux Consultants extérieurs. |
| Coordination Sécurité pour la Phase Génie Civil du Projet LHC |
| Abstract
Partant des constatations que le risque d’accident est deux fois plus important dans le BTP que dans les autres branches d’activité et que 60% des accidents dans le BTP proviennent de choix effectués avant travaux, une directive européenne a été élaborée et a donné naissance à des textes de loi français. La principale mesure résultant de ces textes est la désignation, par le maître d’ouvrage d’un coordonnateur sécurité. Ce coordonnateur est chargé, entre autres, de prévenir les risques de coactivités des entreprises. Il intervient dès la phase de conception en vue d’analyser et de prévenir les risques sur le chantier et dans les interventions ultérieures. Les textes de loi décrivent également les notions de déclarations préalables, aux autorités compétentes, les plans de sécurité rédigés par le coordonnateur et les entreprises, ainsi que le dossier rassemblant les éléments utiles en matière de sécurité et de santé pour d’éventuels travaux ultérieurs. Toutes ces dispositions sont mises en application par le groupe Génie civil du CERN pour la réalisation des ouvrages du projet LHC. |
| Claims in Civil Engineering Contracts |
| Abstract
This paper considers claims arising during civil engineering construction contracts. The meaning of the word ‘claim’ is considered and its possible implications for additional cost and time to completion. The conditions of the construction contract selected will influence the risk apportionment between contractor and client and the price offered by the contractor for the work. Competitive bidding constraints and profit margins in the construction industry, however, may also influence the price offered. This in turn can influence the likelihood of claims arising. The client from his point of view is concerned to complete the work within an agreed time and budget. The circumstances under which claims may arise are reviewed in relation to typical conditions of contract. These circumstances are then related to the CERN LHC civil works. Ways of avoiding claims, where this is possible, are considered. Finally, the means of evaluation of claims and their settlement are considered. |
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