ML20198E659
| ML20198E659 | |
| Person / Time | |
|---|---|
| Issue date: | 07/18/1997 |
| From: | Nataraja M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Stablein N NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 9707280149 | |
| Download: ML20198E659 (4) | |
Text
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July 18,1997 MEMORANDUM TO: N. King Stablein, Acting Chief ENGB/DWM/NMSS Thru: Richard A. Weller, Section Leader Engineering and Material Section ENGB/DWy/NMSS From:
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M. Natar ' l Sr. Geotechnical Engineer Engine ing and Material Section ENGB/DWM/NHSS
SUBJECT:
TRIP REPORT - TO NORWAY - JUNE 22 25,1997 INTERNATIONAL SYMPOSIUM ON ROCK SUPPORT; TECHNICAL VISITS; AND NORWEGIAN GEOTECHNICAL INSTITUTE VISIT, OSLO I attended the International Symposium on Rock Support held in Lillehammer, Norway, June 22 25,1997. I also visited the Gjovik Olympic Mountain Hall (largest underground stadium) and a 14.7 km long single tube rail road tunnel under construction near Oslo, and the Norwegian Geotechnical Institute (NGI) in Oslo, as a part of the post-conference technical visits. This trip report summarizes some salient points of the symposium and the technical visits.
THE SYMPOSIUM More than 60 technical papers covering varied topics, such as design criteria, construction methods and equipment, and production and case histories were presented by representatives coming from some 30 countries. The plenary session consisted of three invited talks. After the initial remarks by the conterence chairman (Mr. Anders Beitnes), the first speaker, (Mr. Willy De Lathauer, President of the International Tunneling Association) spoke about the importance of the symposium and the topic of rock support in general. He discussed how the development of the underground space for civil use has become very important recently. The second invited talk (by Dr.Einar Broch, Professor at the Norwegian University of Science and Technology, Norway) concentrated on the support system design for large rock caverns. Norway is a country which specializes in underground construction in rocks and boasts of numerous projects that are currently in progress. Gjovik Olympic Mountain Hallis a prime example of a large underground project that has been successfully completed and put to good civil use. The talk provided details of this project. The final talk of the plenary session (by the chairman of the symposium) discussed some important aspects of the decision making process in Norway and f/M-/
how the process impacts design, construction, and operation of underground facilities. His main j hypothesis was that when proper incentives are given to the constructor, and when the risks are fairly shared by the designer, constructor, and the owner, the project will have a greater likelihood of meeting schedules and staying within budget. He stressed the importance of hiring h gb g (Q (f :'3 G ,
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'1 N.K. Stablein 2 companies / personnel with appropriate experience and wnting a clear contract which spells out nghts and responsibilities of the parties involved and provides for innovative methods and alterative approaches.
Parallel sessions were held to provide sufficient time for the various presenters, and the audio / video arrangements were excellent. Although a number of papers discussed the application of numerical methods to roof support design and analysis, no new information was presented in this area at the conference. However, the case histories of many projects, which are either complete or in final stages of construction, provided useful insights into the comp!exities of underground construction. There was plenty of interest among the attendees of the conference regarding the American high level waste program. My own presentation on the issue of seismic design methodology went well and I received a number of compliments. Most of the enquiries, however, were focused on the construction schedule for the first United States high-level waste repository. All in all, the symposium was well-organized and well-attended.
VISIT TO GJOVIK OLYMPlc MOUNTAIN HALL Norway is a mountainous country. More than 50 percent of the land surface is exposed rock.
Norway has been a pioneer in using underground space for civil construction. There are more than 200 underground hydroelectric stations and 4000 km of hydropower tunnels and some 700 major highway / railway tunnels. Gjovik Olympic Mountain Hall, carved out of massive gneiss, is one of the largest underground stadiums in the world. Its span is 61 m, length is 91 m and its height is almost 25 m. It can seat more than 7000 spectators. This man-made cavern has been supported by roof bolts and shotcrete and a false ceiling to collect any dripping groundwater. Controlled blasting techniques, employed for excavation, prevented any damage to the existing (mainly residential) surface structures, which are within some 50 meters. A network of geotechnicalinstruments was used for monitoring displacements at various surface locations to document any adverse impacts to existing surface structures. The maximum surface settlement was within 8-10 ram, a value close to that predicted by numerical modeling calculations. The facility was successfully used for the 1994 Winter Olympics. Well-developed emergency plans are in place to effectively evacuate the entire occupants in less than 7 rninutes.
VISIT TO THE ETTERSTAD STALSBERG RAILWAY FUNNEL The 14.7 km long railway tunnel between Etterstad and Stalsberg is one of the major projects currently underway in Norway. The tunnel will connect the new international airport (currently under construction) to the Oslo Central Station, thus, facilitating trasel and easing the traffic congestion. The tunnel design is unique in that two bullet trains (200 km/h) can cross each other in the large single opening that has an area of almost 100 square meters. The roof support consists of roof bolts and shotcrete. The water seepage problem is so severe in some sections that it is literally pouring inside the tunnel (We were supplied with rain coats in addition to boots and hard hats!) A thin shell designed to withstand the enormous air pressure resulting from the passing bullet trains is covered with impervious geo-synthetic fabrics that will prevent the water from entering the tunnel. The water will be diverted into the annular space
N.K. Stcblein 3 and into drains for collection at suitable points. This tunnel construction in discontinuous granite and gneiss using controlled blasting is an example of state of the art in Norwegian tunneling techniques.
VISIT TO THE NORWEGIAN GEOTECHNICAL INSTITUTE ngl in Oslo is a center for research in rock and soil mechanics. Many of the innovative design methods, analytical techniques, and laboratory testing procedures were developed here over the last couple of decades in the fields of soil and rock mechanics. The rock mechanics laboratory at NGlis probably one of the best in the world. In addition to the usual small-scale testing, ngl technicians have developea several large-scale testing capabilities in mechanical, thermal, hydrological and coupled / interactive testing of hard massive ard jointed rocks. ngl provides consulting services to the oil and gas industry and many of the Norwegian Government u%1ertakings.
Significant amount of work is going on in the area of numerical modeling. One of the current research projects is applying the concepts developed by Norwegian tunneling experts to an undergrouno power station construction in the Himalayas. A researcher at ngl has used the field measurements and observations at this Indian underground power station in the Himalayas to prepare a doctoral thesis. I had the rare opportunity of sitting through his doctoral thesis defense as an observer at the institute of Geology, University of Oslo. The thesis uses the updated Q-System, statistical evaluation of rock mass jointing, and the shear resistance of the joints as inputs to stability analysis of large underground openings using UDEC computer code.
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The visit to ngl and discussions with many of the researchers who have participated in the DECOVALEX program and with several academicians at the Institute of Geology provided an opportunity to keep me updated with the state of the art.
I have a copy of the symposium proceedings, a booklet on Gjovik Mountain Hall, and a copy of the doctoral dissertation for anyone interested in browsing through.
Q1STRIBUTION: Central File NMSS r/f ENGB r/f PUBLIC JGreeves MFederline CPaperiello MBell CStolbe( SBahadur DJBrooks kMcConnell SWastler OSR CNWRA TAhn KChang DDancer JDavis KGruss JBradbury NColeman Albrahim PJustus BLeslie JPohle FRoss JTrapp DOCUMENT NAME: S:\DWM\ENGBtMSN\NORWYTRP.RPT OFC ENG13( ENGB ,
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