NORWEGIAN TUNNELLING SOCIETY NORWEGIAN Are you looking for tunneling technology and experience? NORWEGIAN TUNNELLING Check out: TECHNOLOGY www.tunnel.no The Tunneling Technology Website NORWEGIAN T UNNELLING T ECHNOLOGY You will find: – Consultants and experts – Contractors – Equipment and Suppliers – Applied technology – Project descriptions – Publications A NFF (Norwegian Tunnelling Society) PUBLICATION NO. 23 NO. PUBLICATION NORWEGIAN TUNNELLING SOCIETY initiative to promote modern, cost and time efficient tunnelling PUBLICATION NO. 23 nORWegian TUnneLLing sOCieTY REPRESENTS EXPERTISE IN • Hard Rock Tunneling techniques • Rock blasting technology • Rock mechanics and engineering geology Used in THe design and CONSTRUCTION OF • Hydroelectric power development, including: - water conveying tunnels - unlined pressure shafts - subsurface power stations - lake taps - earth and rock fill dams • Transportation tunnels • Underground storage facilities • Underground openings for for public use NORSK FORENING FOR FJELLSPRENGNINGSTEKNIKK Norwegian Tunnelling Sosiety [email protected] - www.tunnel.no - www.nff.no nORWegian TUnneLLing sOCieTY REPRESENTS EXPERTISE IN • Hard Rock Tunneling techniques • Rock blasting technology • Rock mechanics and engineering geology NORWEGIAN TUNNELLING Used in THe design and TECHNOLOGY CONSTRUCTION OF Publication No. 23 • Hydroelectric power development, including: - water conveying tunnels NORWEGIAN TUNNELLING SOCIETY - unlined pressure shafts - subsurface power stations - lake taps 2014 - earth and rock fill dams • Transportation tunnels • Underground storage facilities • Underground openings for for public use NORSK FORENING FOR FJELLSPRENGNINGSTEKNIKK Norwegian Tunnelling Sosiety [email protected] - www.tunnel.no - www.nff.no DESIGN/PRINT BY HELLI - VISUELL KOMMUNIKASJON, OSLO, NORWAY NorwegiaN TunnelliNg SocieT y PublicaTioN No. 23 PUBLICATION NO. 23 © Norsk Forening for Fjellsprengningsteknikk NFF ISBN 978-82-92641-30-9 Front page: Stetind, courtesy: Norwegian Public Roads Administration Layout/Print: HELLI - Visuell kommunikasjon AS [email protected] www.helli.no DISCLAIMER “Readers are advised that the Publications from Norwegian Tunnelling Society NFF are issued solely for informational purposes. The opinions and statements included are based on reliable sources in good faith. In no event, however, shall NFF and/or the authors be liable for direct or indirect inciden- tal or consequential damages resulting from the use of this information” 4 NorwegiaN TunnelliNg SocieT y PublicaTioN No. 23 FOREWORD The present publication, No. 23 in the English language series from the Norwegian Tunnelling Society NFF, has – as always – the intention of sharing with our col- leagues and friends internationally the latest news and experience gained in the use of the underground; this time with focus on tunnelling technology in general. Publication No 1 - “Norwegian Hard Rock Tunnelling” issued 32 years ago may have given an impression of a mountainous country with entirely solid, competent rock. The picture is more complicated, several incidents underscore variety. Developers set new benchmarks for safety and quality, more pre-investigation is necessary, plans and specifications are more detailed as are the contract documents. The basic situation, however, is unchanged. Cooperation, contribution and flex- ibility are still common approach, modifications take place when appropriate and in the context of durability and maintenance costs as seen from the owners; safety and reliability as seen from the public; methods, techniques and materials as seen from scientists, advisers, suppliers and contractors. Publication 23 is prepared by NFF members. Some details on the authors are included in Annex I. On behalf of NFF it is a privilege to express our sincere thanks to the Editorial Committees and the Authors. Without their efforts the preparing of this publication would not have been possible. Oslo, May 2014 Norwegian Tunnelling Society International Committee 5 CONTENTS FOREWORD................................................................................................................................................................ 5 01. INTRODUCTION .............................................................................................................................................. 13 Background .........................................................................................................................................................13 Development of Tunneling in Norway ...............................................................................................................14 In the Hall of the Mountain King .......................................................................................................................15 Norway, a nation of notorious risk takers? And why? .......................................................................................15 Concluding remark .............................................................................................................................................16 02. GROUND INVESTIGATIONS FOR NORWEGIAN TUNNELLING.......................................................... 19 1 Introduction ....................................................................................................................................................19 2 Investigation stages ........................................................................................................................................19 3 Pre-construction investigation methods .........................................................................................................22 4 Construction stage investigation methods......................................................................................................29 5 Investigations during operation ................................................................................................................................................31 6 Extent of investigation ...................................................................................................................................32 7 Concluding remarks .......................................................................................................................................33 References ..........................................................................................................................................................33 03. EXCAVATION AND SUPPORT METHODS ................................................................................................... 35 1 Introduction ....................................................................................................................................................35 2 Excavation methods .......................................................................................................................................35 3 Water control ..................................................................................................................................................36 4 Contracts ........................................................................................................................................................36 5 Rock Support Philosophy and Practices ........................................................................................................37 6 Geological Pre-Investigations and Feasibility Studies ..................................................................................37 7 Investigations during tunnel excavation ........................................................................................................38 8 Expertise at the tunnel face during scaling and geological mapping ............................................................38 9 Permanent Rock Support Strategy .................................................................................................................39 10 Ground freezing............................................................................................................................................41 References ..........................................................................................................................................................43 04. TUNNEL AND CAVERN SUPPORT SELECTION IN NORWAY, BASED ON ROCK MASS ­cLASSIFICATION WITH THE Q-SYSTEM.................................................................................................. 45 1 Introduction ..................................................................................................................................................45 2 How and why Q was developed ................................................................................................................45 3 Classification method briefly described .........................................................................................................45 4 Examples of core-logging with Q .................................................................................................................47 5 Additional advice concerning core logging ...................................................................................................48 6 Characterizing surface exposures with examples ..........................................................................................49 7 Additional advice concerning surface exposure logging ...............................................................................49