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Engineering geology of the MICA underground powerplant
32A
However, fallouts of rock in such tunnels are not uncommon and in mar~ cases have been attributed to erosion of shears and seams. A case history of such a fallout is described. An appraisal of the conditions pertaining to the fallout led to the conclusion that rapid char~es in the water pressure in the tunnel resultillg from operating conditions were significant factors in initiating the fallout. Other factors that contributed to the fallout ere also described. Auth.
782075
AS-BUILT GEOTECHNICAL REPORT: ITS USE FOR DESIGN OF SUPPORT FOR THREE ROCK STATIONS, WASHINGTON, D C METRO Bock, C G Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P430-~7 The three rock station areas have been explored by crown pilot tunnels and an as-built report, with geologic maps and sections, has been prepared, for use by the design engineer as the basis of design for support of the structures. The report describes the geologic structure in detail amd relates it to excavation anl support of the three crown pilot tunnels and the running tunnels. The information was complete enough to permit the design engineer to visualize the geologic structure and compute loads for the various types of rock conditions. It was therefore possible to determine the size and spacing of the steel sets for the several different conditions of rock structure encountered in the pilot tunnels.
782076 PRECAST CONCRETE SEGMENT LINING FOR BUCKSKIN MOUNTAINS WATER CONVEYANCE Groseclose, W R; Schoeman, K D Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P448-463 The 22-foot, precast concrete segments are being used as a single system initial support and final lining in the tunnel being excavated by a tunnel boring machine specially designed and built for the Job by The Robbins Compsm~. 782077 A U S ~ I A N METHOD OF TUNNEL BUILDING IN VERY HF_~VILY SQUEEZING GROUND IN MOUNTAINOUS TERRAIN - THEORY AND PRACTICE Pochhacker, H Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976,
I~4-512 Discusses the method in detail ar~ refers particularly to the Tauern tunnel in Austria, and the exceptional support measures required, including (in the werst ground) 4m anchors, steel fabric mat, tunnel arch ar~ 25cm shotcrete. 782078 HIGH PRESSURE WATER JET ASSISTED TUNNELING Wang, F D; Miller, R Proc Rapid Excavation amd Turmelling Conference, La~ Vegas, 14-17 June 1976,
P649-676 Tests were conducted in a granite quarry. A 7-ft diam tunnel baring machine was modified and equipped with high pressure water Jets. There was an avers~e increased advance rate of 50 per cent to bO per cent. Far some tests, the advance rate was mc~e than doubled. A comprehensive economic ar~lysls has sho~n that significant savings are possible. At a 50 per cent increase in advance rate, cost
savings of 14 per cent and 24 per cent were projected for 10-ft and 20-ft diam ttmnels respectively. These benefits were seen to be relatively insensitive to water Jet equipment costs. 782079 FEASIBILITY OF DEVELOPING ARCTIC OIL AND GAS RESERVES BY TUNNELING McCusker, T G; Tarkoy, P J Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P677-696 Discusses the geology and environment of the N c ~ American Arctic and gives a brief geotechnlcal evaluation of the types of ground encountered, sedimentary rocks, unconsolidated granular sediments and silt, with permafrost effects. Finally discusses construction problems peculiar to the area. 782080 BEHAVIOR STUDIES FOR A HIGHWAY TUNNEL Misterek, D L; Slebir, E J; Ring, G W Proc Rapid Excavation and Tunnelling . Conference, Las Vegas, 14-17 June 1970, 1o715-721 During the construction of the second bore of the Eisenhc~ar Highway Tunnel, in situ tests, instrtunentation programs, and laboratory investigations are to be performed. The data obtained relate to the reaction of the rock mass when subjected to construction activities, the extent of the zone of influence, and the responses of the support and lining components. Together with the tunnel construction monitering program, the investigation is expected to provide a better umderstar~ing of the behavior of a large diameter tunnel, before, during, and after construction. 782081 CONSI~UCTION CONTROL INSTRUMENYATION USED DURING TUNNEL ENLARGEMENT Robinson, R A; Miller, R P; Monson, D L Proc Rapid Excavation and Tunr~lling Conference, Las Vegas, 14-17 June 1976, P742-758 A geotechnical instr~nentatlon programme consisting of bore~hole extensometers and portable tape extensometer stations was effectively used to monitor concrete liner deformations and guide construction procedures during enlargement of a 75-year old Union Pacific Railroad tunnel in Wyoming. Enlargemerit involved excavation of the old concrete invert and placement of 5,941 feet of new concrete invert 6 feet lcwer in squeezing shales, fault zones and watar-bearing samdstoncs. Instr~nentation data were used to guide procedures for excavating the old invert, installation of temporary interior struts, underpinning existing liner walls, and placing the new concrete invert. Auth.
782082 URBAN
TUNNELING TECHNOLOGY - EUROPEAN EXPERIENCES Jacob, E J Proc Rapid Excavation and Tunnellir~ Conference, Las Vegas, 14-17 June 1976,
P794-808 Surveys both hard rock and soft ground tunnelling, and also discusses tunnel linings.
However, fallouts of rock in such tunnels are not uncommon and in mar~ cases have been attributed to erosion of shears and seams. A case history of such a fallout is described. An appraisal of the conditions pertaining to the fallout led to the conclusion that rapid char~es in the water pressure in the tunnel resultillg from operating conditions were significant factors in initiating the fallout. Other factors that contributed to the fallout ere also described. Auth.
782075
AS-BUILT GEOTECHNICAL REPORT: ITS USE FOR DESIGN OF SUPPORT FOR THREE ROCK STATIONS, WASHINGTON, D C METRO Bock, C G Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P430-~7 The three rock station areas have been explored by crown pilot tunnels and an as-built report, with geologic maps and sections, has been prepared, for use by the design engineer as the basis of design for support of the structures. The report describes the geologic structure in detail amd relates it to excavation anl support of the three crown pilot tunnels and the running tunnels. The information was complete enough to permit the design engineer to visualize the geologic structure and compute loads for the various types of rock conditions. It was therefore possible to determine the size and spacing of the steel sets for the several different conditions of rock structure encountered in the pilot tunnels.
782076 PRECAST CONCRETE SEGMENT LINING FOR BUCKSKIN MOUNTAINS WATER CONVEYANCE Groseclose, W R; Schoeman, K D Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P448-463 The 22-foot, precast concrete segments are being used as a single system initial support and final lining in the tunnel being excavated by a tunnel boring machine specially designed and built for the Job by The Robbins Compsm~. 782077 A U S ~ I A N METHOD OF TUNNEL BUILDING IN VERY HF_~VILY SQUEEZING GROUND IN MOUNTAINOUS TERRAIN - THEORY AND PRACTICE Pochhacker, H Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976,
I~4-512 Discusses the method in detail ar~ refers particularly to the Tauern tunnel in Austria, and the exceptional support measures required, including (in the werst ground) 4m anchors, steel fabric mat, tunnel arch ar~ 25cm shotcrete. 782078 HIGH PRESSURE WATER JET ASSISTED TUNNELING Wang, F D; Miller, R Proc Rapid Excavation amd Turmelling Conference, La~ Vegas, 14-17 June 1976,
P649-676 Tests were conducted in a granite quarry. A 7-ft diam tunnel baring machine was modified and equipped with high pressure water Jets. There was an avers~e increased advance rate of 50 per cent to bO per cent. Far some tests, the advance rate was mc~e than doubled. A comprehensive economic ar~lysls has sho~n that significant savings are possible. At a 50 per cent increase in advance rate, cost
savings of 14 per cent and 24 per cent were projected for 10-ft and 20-ft diam ttmnels respectively. These benefits were seen to be relatively insensitive to water Jet equipment costs. 782079 FEASIBILITY OF DEVELOPING ARCTIC OIL AND GAS RESERVES BY TUNNELING McCusker, T G; Tarkoy, P J Proc Rapid Excavation and Tunnelling Conference, Las Vegas, 14-17 June 1976, P677-696 Discusses the geology and environment of the N c ~ American Arctic and gives a brief geotechnlcal evaluation of the types of ground encountered, sedimentary rocks, unconsolidated granular sediments and silt, with permafrost effects. Finally discusses construction problems peculiar to the area. 782080 BEHAVIOR STUDIES FOR A HIGHWAY TUNNEL Misterek, D L; Slebir, E J; Ring, G W Proc Rapid Excavation and Tunnelling . Conference, Las Vegas, 14-17 June 1970, 1o715-721 During the construction of the second bore of the Eisenhc~ar Highway Tunnel, in situ tests, instrtunentation programs, and laboratory investigations are to be performed. The data obtained relate to the reaction of the rock mass when subjected to construction activities, the extent of the zone of influence, and the responses of the support and lining components. Together with the tunnel construction monitering program, the investigation is expected to provide a better umderstar~ing of the behavior of a large diameter tunnel, before, during, and after construction. 782081 CONSI~UCTION CONTROL INSTRUMENYATION USED DURING TUNNEL ENLARGEMENT Robinson, R A; Miller, R P; Monson, D L Proc Rapid Excavation and Tunr~lling Conference, Las Vegas, 14-17 June 1976, P742-758 A geotechnical instr~nentatlon programme consisting of bore~hole extensometers and portable tape extensometer stations was effectively used to monitor concrete liner deformations and guide construction procedures during enlargement of a 75-year old Union Pacific Railroad tunnel in Wyoming. Enlargemerit involved excavation of the old concrete invert and placement of 5,941 feet of new concrete invert 6 feet lcwer in squeezing shales, fault zones and watar-bearing samdstoncs. Instr~nentation data were used to guide procedures for excavating the old invert, installation of temporary interior struts, underpinning existing liner walls, and placing the new concrete invert. Auth.
782082 URBAN
TUNNELING TECHNOLOGY - EUROPEAN EXPERIENCES Jacob, E J Proc Rapid Excavation and Tunnellir~ Conference, Las Vegas, 14-17 June 1976,
P794-808 Surveys both hard rock and soft ground tunnelling, and also discusses tunnel linings.