5th FCC Infrastructure & Operation meeting 1. Progress on tunnel cross-section options 2. A simplified model for the cost of a “smooth” tunnel excavated by TBM in sedimentary rock Ph. Lebrun & J. Osborne 5th FCC Infrastructure & Operation meeting CERN, 28 May 2014
Single tunnel, longitudinal ventilation Revised Ph. Lebrun FCC I&O meeting 140528
Double tunnel Revised Ph. Lebrun FCC I&O meeting 140528
Single tunnel, transverse ventilation To be revised with ventilation duct cross-sections Lebrun, Osborne, Collier FCC I&O meeting, 140326
Tunnel cost model: a word of caution The simplified cost model presented here is based on the study performed by Amberg Engineering for the CLIC CDR cost estimate Strictly valid for hard-rock TBM tunnelling in the molasse of the Geneva basin, it is based on a set of unit costs applicable to geology, depth below ground, tunnel size and configuration, excavation equipment, rock support, lining and sealing techniques, progress rates, personnel, materials, transport and handling Consequently, the model should not be used for estimating tunnel costs outside its range of validity It is recommended to use output results for relative cost comparison rather than absolute cost assessment Ph. Lebrun FCC I&O meeting 140528
CLIC 3 TeV tunnel profile Ph. Lebrun FCC I&O meeting 140528
CLIC tunnel cross-section Ph. Lebrun FCC I&O meeting 140528
Shafts, caverns and other singularities Ph. Lebrun FCC I&O meeting 140528
Methodology of Amberg study for CLIC underground works [1/2] Standard profiles were developed for each underground structure, including details on the excavated cross sections as well as the inner lining. For each of these standard profiles, the following main items are evaluated in quantity and price: Labour for workmanship like workers and foremen (below senior level) (shift work system: 3 shifts working 24 h/day, 7 days/week, 320 days/year , rest: official holidays and maintenance) Tunnel excavation with shielded TBM and single-pass pre-cast concrete lining, mucking and disposal Rock support for caverns by means of rock bolts with steel-fibre shotcrete Full sealing of the caverns and halls, as well as collecting and diverting of dropping water in the remaining structures Inner lining considered with reinforced concrete Implementation of an invert with sufficient bearing capacity to withstand the probable swelling pressure of the present Molasse Connection works to the neighbouring contracts Ph. Lebrun FCC I&O meeting 140528
Methodology of Amberg study for CLIC underground works [2/2] The previously listed main items cover basically 55 – 65 % of the final costs. Given the preliminary phase of the study, some further costing positions were added to the main items as percentage surcharge of the subtotal: Drainage including the pumping stations at the shaft bases (4%) Quality control (2%) Auxiliary measures (15%) such as pre-investigations, pre-injections, ground improvement Installations and equipment for construction works (e.g.: TBM, excavators, cranes, lorries) (30-40%) Overhead (15.9%) (according to the calculation scheme of Swiss Contractor Ass.) including: - surcharges on hourly wages e.g. for shift works 24 h/day and 7 days/week, workmen’s equipment, recruiting and training, - maintenance and operation of the workshops and site installations, - senior personnel for management and surveillance, - administration costs and interest rates, - insurance and contributions Ph. Lebrun FCC I&O meeting 140528
Amberg study for CLIC underground works Ph. Lebrun FCC I&O meeting 140528
Simplified cost model of TBM excavated tunnel Specified free diameter D Excavated diameter Dexc = D + 2 (tolerance + lining thickness+ grouting thickness) Cost per meter C = C1 + C2 + C3 + C4 + C5 C1 fixed cost per meter (e.g. TBM personnel for given progress rate) C2 proportional to excavated volume ~ Dexc2 C3 proportional to lining & grouting volumes ~ Dexc C4 proportional to invert (floor) volume C5 cost per meter of additional construction elements (partitions, firewall) Cost per meter of finished tunnel is expected to scale between D and D2 Ph. Lebrun FCC I&O meeting 140528
EXCEL table All dimensions and unit costs adjustable Ph. Lebrun FCC I&O meeting 140528
Cost of tunnel vs finished diameter (TBM in sedimentary rock, no additional construction) Ph. Lebrun FCC I&O meeting 140528
Cost structure of tunnel (TBM in sedimentary rock, no additional construction) Ph. Lebrun FCC I&O meeting 140528