123A

Tunnels

See ulso: X542-73. 854236

854131 Fullfacers triple up for CERN drive Hayward, D lliew Civ Engr 7 March 1985, P34-37

A 27.6km long tunnelling ring with a network of 18 shafts and 20 vast caverns will be used for subnuclear particle physics research. An account of the project, which is to begin fullface driving, is presented.

854132 Tunnelling through warp: an estuarine clay Slocombe, R T Q J Engng Geol VI 7, N4, 1984, P349-350

A 2.4km tunnel was successfully constructed through soft silty clay of estuarine deposits. Details of its construction are pre- sented illustrating the use of low pressure compressed air to reduce both water inflow and settlement by helping to support the exposed deposits.

854133 Longest road tunnel in Yugoslavia (In German and English) Banjad, I Tunnel Nl, Feh 1985, P16-20

A 5km road tunnel has been driven though carbonate and loose marl rocks in the Istrian Peninsular, Yugoslavia, using the New Austrian Tunnelling Method. Support during drivage was by shotcrete and rock bolts, with tunnel arches and steel grids where rock pressure was greatest.

854134 Agnesburg Tunnel near Aalen/Wuttemherg (In German and English) Langer. A Tunnel Nl, Feb 1985, P21-25

A road tunnel in the Eastern Alb. Germany, is being con- structed using the New Austrian Tunnelling Method. The con- tinuous miner, chosen for drivage, uses laser and computer control to ensure accurate rock cutting. Reinforced shotcrete. bolts and tunnel arches have been used as support, but require- ments are kept to a minimum through achievement of a high profile accuracy during drivage.

854135 Update on trends in soft ground tunnelling machines Stack, B Tunn Tunnlg V17, NI, Jan 1985, P21-23

Current developments are reviewed with particular reference to tail seals, slurry, earth pressure balanced and mud and earth pressure balanced shields and the use of disc cutters and crushers to cope with mixed ground conditions.

854136 Mini slurry shield provides Singapore subway Rooke. A Tunn Tunnlg VI 7, Nl, Jan 1985, P40-41

A horizontal cofferdam, an adaption of the pipe roofing techni- que, was constructed as the first stage in driving a 33m pedestrian underpass in Singapore. 28 pipes of 560mm dia- meter. each held together with a pair of IOOmm steel pipes to form a sealed unit, were installed by pipe jacking using a remote controlled slurry shield. The equipment chosen incorporated a hydraulic face pressure mechanism, which balanced earth and slurry pressure, allowing pipes to be installed with little or no

ground settlement and little disturbance of groundwater level. The tunnel was excavated inside the pipe cofferdam. with steel support frames to take heavy loading from the traffic and wet earth and finally a concrete lining to form a permanent com- posite structure.

854137 Four Japanese tunnels to get the bullet Martin, D Tunn Tunnlg VI 7, Nl, Jan 1985, P45-46

A tunnel is being driven at Fukunanzan, Japan, for the bullet train. The ground is an abrasive granodiorite, thus the drill and blast technique was chosen, using an electro-hydraulic jumbo. Up to 150 blast holes are drilled at the face. with depths l-3.5,. depending on rock stability. Intermediate reinforcement is given by shotcrete and rock bolts, plus conventional steel arches in the less competent rock areas. A 30cm concrete lining will complete the tunnel.

854138 Sealants for smooth bore tunnel lining Water Serv V88, X1064, Ocr 1984, P443

The use of pre-cast concrete sections and bitumen based sealants for relining of sewers is described.

Power plants

See also: 854237

854139 Superhydro Danilevsky, A Civ Engng, N Y V54, Nil, Not 1984, PSS-57

Development of the Bath County pumped storage project is described. Seepage may destroy the mountain ridge between the reservoirs so rock and groundwater behaviour is continuously monitored. Over 400 piezometers will be installed in the upper dam before reservoir filling. An electronic system for data ac- quisition and processing will monitor the completed project. Minor problems with rock faults and slope instability have been solved using rock anchors.

854140 Guatemalan gremlins wreak havoc underground Tunn Tunnlg V17, NI, Jan 1985, P14-19

Water and gas ingress and rockfalls caused many major prob- lems in driving a 26km pressure tunnel through faulted and fol- ded karstic lithology in Guatemala. Progress in m/week for the different machines used, support necessary and water ingress are described. The full face tunnel boring machine proved superior to other methods used under these conditions.

854141 Unique geotechnical problems at some hydroelectric projects Deere, D U Proc 7th Panamerican Conference on Soil Mechanics and Foundation Engineering, Vancouver, June 1983 V3, P865-888. Pub1 Montreal: Canadian Geotechnical Societjs, 1983

Experience in Norway with unlined pressure tunnels and case histories of the failure of plain concrete lined pressure tunnels in soft rock are described. Problems relating to the use of im- permeable (steel), slightly permeable (reinforced concrete) and semi-permeable (plain concrete, shotcrete) linings are con- sidered. Analysis of case studies from South America suggests a conservative approach should be taken when designing, buil- ding and operating pressure tunnels in relatively hostile en- vironments.