INTERNATIONAL SEMINAR LONG TUNNELS

Transcription

1 INTERNATIONAL SEMINAR LONG TUNNELS Desafío para el Diseño, Construcción y Operación Challenges for Design, Construction and Operation Construction of long road s in Norway including the Lærdal Chief Scientist Professor Eivind Grøv SINTEF/NTNU and SKAVA when in Chile Past President Norwegian Tunnelling Society Past Vice President ITA 17, 18 y 19 de Octubre 2012 Santiago, Chile PIARC CHILE

2 Construction of long road s in Norway Long traffic s in Norway 3 of the 10 longest road s in the world are in Norway 30 (++) road s are longer than 5 km Appr. 10 of these are subsea s Appr. 5 are longer than 10km 2 railway s are longer than 10 km, dating back to the nineties and the seventies Plans are under preparation for Follo-Ski 2 x 20 km rail way s Rogfast 2 x 25 km sub sea road to -390 Ryfast 2 x 14,3km sub sea

3 Construction of long road s in Norway Motivation for our study: How to better plan the physical construction of long s Tunnelling, short or long s is basically a matter of logistics It is the master minding of careful and intelligent logistics and planning Often this is the contractors competitive edge Having reached that recognition does it really matter whether the is 5 or 25 km long? The challenge is: how to achieve an industrial production process when there is one access for all works to be done. Is it relevant to leave the solely to complete excavation works?

4 Construction of long road s in Norway Key-issues to be focused during construction: Health and safety aspects Ventilation Mucking out/transportation Initial support become permanent support Time schedule How to improve these aspects? Problem defined as; limited access & confined space

5 Project Type of project Tunnel length Construction of long road s in Norway Overburde n Tunnel width Number of exits/entran ces Number of working faces Maximum length of face Constructio n time (mobilisatio n to opening of the s) Lærdal Road Folgefo nn Road Bømlafj ord Sub sea road Eiksun d Subsea road Atlanterh avs Subsea road Frøya Subsea road Korgfjel let Road Steigen Romerikspo rten Oslofj ord Road Railway Subsea road Gudvang en Road 24.5 km 11 km 7.9 km km km 5.3 km km m km m km 1400 m >800 m rock cover for 20 km 9 m (dual lane, single tube) adit 8 m (dual lane, single tube) 262 meter below sea level, min. 35 m rock cover 11 m (triple lanes single tube) 287 meter below sea level Partly 11.5 m and partly 9.5 m (single tube, 2/3 lanes) 245 m below sea level. Approxima tely 40 m rock cover 11 m (single tube, mostly three lanes) 164 m below sea level. Rock cover m. 8 m (single tube, two lanes) 10 to 250 m 134 m below sea level (min. 32 m rock cover) 8 m 7 m 11 m 11 m (three lanes) adits adit Approx. 9 km July 1995 Novemb er 2000 Approx. 6 km May 1997 May 2001 Approx. 4 km Septemb er Decembe r 2001 Approx. 5 km February 2003 February 2008 Approx. 3 km. August 2006 spring 2009 (planned) Approx. 8 m 2.6 km 4.5 km 4.3 km 3.6 km 3 km 6 km January June 2000 October 2001 Septemb er August August 1999 April June Opened in December 1991

6 Construction of long road s in Norway Project Lingvang Breidal Tyin Svea Dividalen Troll Langevann, IVAR Type of project Water transfer Water transfer Headrace Coal transport Access to radar site Subsea pipeline Water transfer Tunnel length 8.9 km 10 km 11,3 km 5.7 km 9.8 km 7.5 km 7.8 km Tunnel width 5 m 5 m 7 m 3.6 m (18 m 2 ) m (25 m 2 ) (20 m 2 ) m Overburden Approximately 600 m Up to 1000 m rock cover. Up to 600 m (half of is below a glacier) 180 m below sea level (7m piercing) Number of exits/entrances Number of working faces Maximum length of face adit 1 1 (+ 1 adit for air and dump site) adit (?) (?) 8.9 km 5 km 4.4 km 5.7 km 9.8 km 3.6 km 4 km (?) Tunnelling method Construction time (mobilisation to opening of the s) Notes Drill & blast Drill & blast Drill & blast Drill & blast Drill & blast Drill & blast October 2001 September 2003 November 2002 December 2003 Started in permafrost September 1990 September m height difference or 1 : 7 uphill October 1991 January 1996 Lowest level 240 m below sea level Drill & blast April1997 November 2002

7 Construction of long road s in Norway A crucial parameter when it comes to long s, large cross sections width > 8m: Room for efficient loading, transportation and mucking out, no need for niches Sufficient ventilation and large size vent ducts, two way Multitasking in terms of several activities taking place simultaneously as the face is progressing Whilst small cross sections: Lack of room makes the entire logistic exercise difficult

8 Construction of long road s in Norway Norwegian contract practice On one hand: The Owner carries the risk for the ground conditions The Owner is responsible for the collection of information on ground conditions. All information is disclosed to the tendering contractors for their own interpretation. The Owner provides his interpretation of the situation in terms of estimates on quantities on rock support, grouting etc. Whilst: The Contractor carries the risk for the appropriate and efficient handling of the works and focus on improving his technical and organizational performance. The contracts include regulations for extension of construction time based on actually performed quantities, Standard capacities, or equivalent time system.

9 Construction of long road s in Norway Risk sharing principle

10 Construction of long road s in Norway Project references

11 Construction of long road s in Norway The Lærdal, - the longest road in the world, and open for general public traffic

12 Construction of long road s in Norway Implemented in the Lærdal Tunnel Rock Crystals Zhongnanshan Tunnel, China, The worlds longest twin tube : 18 km

13 Construction of long road s in Norway Sectional completion-lærdal Most of the permanent rock support was installed at or close to the face. The lower part of the road embankment was replaced every week to be able to have an appropriate transport surface. Work was going on continuously with the construction of the ditch and with the installation of drainage pipes, cable canals and cables. Twice a year the permanent road embankment was established in addition to the first layer of asphalt. This was the permanent road construction, but approval was granted for use in the construction period.

14 Construction of long road s in Norway Entrance to the 11 km long Folgefonn

15 Construction of long road s in Norway Sectional completion - Folgefonn Blast and excavate the and the ditch simultaneously. Install all permanent rock support at the face, or at least before the installation of the ventilation duct. Install all equipment in the ditch in sections of m. Utilize the excavated rock as road embankment. A temporary asphalt layer to be laid allowing transport to take place on a covered surface. Installation works, except rock support, were not allowed to take place closer than 400m from the face.

16 Construction of long road s in Norway The Bømlafjord sub-sea south of Bergen 7,9 km long sub sea Reaches to - 240m At the steepest inclined 8,5% One contractor at each side

17 Construction of long road s in Norway Sectional completion - Bømlafjord subsea The contractor completed sections with length of approximately 1000 m. Due to the poor quality of the rock all blasted rock needed to be replaced, and the sectional completion included a complete re-establishing of the road embankment. The completion included rock support, ditches, drain pipes, man holes, cable canals and electrical/fiber-optic cables. The completion included also a first layer of asphalt.

18 Construction of long road s in Norway Bømlafjord, - disadvantages of not using sectional completion experienced by the second contractor A permanent sand filter facility had to be established outside the to clean drainage water due to large production of fines. The material in the road embankment of the temporary road in the was crushed due to the load from the heavy traffic. Additional ventilation fans due to large amounts of dust and exhaust air. Dirty working conditions affected negatively the Health and Safety aspects in the. Frequent local replacement of road embankment to maintain construction traffic.

19 Construction of long road s in Norway The feedback from owners and contractors: Significant challenge to the contractor in planning his works Increased manning and demand on equipment Improved Health&Safety during construction Owners report time savings Reduced cleaning of interior Contractors valued aspects related to transport and hauling, increased efficiency, reduced maintenance on equipment and tear & wear Everyday production increased The contract has to address specific instructions, time and incentives

20 Construction of long road s in Norway Time is money in the ling industry! Potential advance rate (good fair rock conditions, easy or no pregrouting, min. support): 4,8 m net penetration per round, 2 rounds per day, 6 days per week: 58 m/week High intensity pre-grouting, increased support: 2 rounds per every 2 nd day: 29 m/week Very poor rock: 1 round per day, net penetration 2,5 m: 15 m/week Projects have had up to 175m/week with drilll&blast Various comparisons done suggest a factor from 3-10 more cost efficient ling in Norway! Lærdals appr. 8.2 mill Euro per km Romeriksporten railway appr. 16 mill Euro per km One needs to ask WHY!!!

21 Construction of long road s in Norway Aspects to be focused during construction High capacity equipment, multi-skilled workmen at the ling face allowing high utilisation of the equipment. Adaptability to the actual ground conditions, careful following-up of the encountered rock mass by mapping and classification for a best fit of rock support measures. Observation of the ground behaviour by visual surveying and physical measurements if required fulfilling the intentions of the Observational method. Installation of permanent rock support as close to the face as practically possible fulfilling the criteria for permanent support work.

22 Construction of long road s in Norway Unique Co-operation at the site Constructive cooperation between the representatives of the involved parties. Experienced professionals participating in the decision making. Solve conflicts at construction site by negotiation after the technical issues have been settled.

23 Construction of long road s in Norway Hard rock environment The Scandinavian host rock varies from poor to extremely good rock. Folding, faulting and high tectonic stresses influence the quality of the rock Weakness zones can exhibit great variation in quality, Q-values may vary from extremely poor to good The width of such zones may vary from a few centimeters to tens of meters Permeability may vary significantly The CHALLENGE: to deal with frequently changing ground conditions It is typical Hard Rock not necessarily Good Rock

24 Construction of long road s in Norway Conclusions! Take care of your logistics! All parties benefit from a reduced construction period! Sectional completion is a way to secure this goal for long construction Sustainability and CO2 emission are issues to keep in mind also The ultimate goal of our efforts: Reduce the construction time on overall, not sub optimize single activities Thank you for your kind attention!

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