designed omission of linings in the tunnels for the lesotho highlands water project excavate and support in the 90s, proc sanco

designed omission of linings in the tunnels for the lesotho highlands water project excavate and support in the 90s, proc sanco 关于铁凝的作文 放牛班的春天观后感 Designed omission of linings in the tunnels for the Lesotho Highlands water project Excavate and Support in the 90s, Proc SANCO 392A 916482 ‘Shake and slip to survive’ - tunnel design Desai, D B; Merritt, J L; Chang, B Proc 1989 Rapid Excavation and Tunnelling Conference, Los Angeles, 11-14 June 1989 P13-30. Publ Littleton: SME, 1989 Experiences in constructing a large diameter sewer at shallow depth in a seismic zone are presented. The NORS alignment in Los Angeles runs through marine and continental sediments, mainly above groundwater table. Fault crossings were designed using concepts developed by the petroleum industry and adapted to the constraints of an urban project. Segmented concrete pipe with flexible neoprene joints, surrounded by a thick layer of compressible backfill, was used to accommodate ground movements expected on fault displacement. 916486 Underground hydropower comes of age Wallis, S Tunn Tunnlg 1/23, N4, April 1991, P37-40 Details are presented of two hydroelectric projects in Taiwan, the Mingtan scheme and expansion of the Tienlun scheme. The former, a pumped storage project, is in sandstone and shale rocks, characterised by faults,folds, joints, and shear zones. The cavern roof was pre-reinforced before excavation, using anchors installed from drainage and working galleries. Immediate support is by shotcrete, bolts, and anchors. New tunnels for Tienlun are driven by drill and blast, with support according to NATM principles. The rock is generally good quality sandstones, quartzite, argillite, and shale, but problems have arisen while crossing known fault zones. 916483 Temporary tunnel support by precast segments Ruemmele, W A; Wardell, S A Proc 1989 Rapid Excavation and Tunnelling Conference, Los Angeles, 11-14 June 1989 P87-93. Publ Littleton: SME, 1989 Construction of two sections of the Los Angeles Rail Project, 6.7m/5.5m excavated/finished diameter twin bore tunnels, is described. Most of the excavation was beneath city streets in weak siltstone/claystone bedrock at cover depth 10-25m. Some fine grained alluvium was also met. Open faced, digger- equipped shields were used. Initial tunnel lining was by precast concrete segments. Project requirements, reasons for selection of lining type, and advantages and disadvantages of this lining type are discussed. Power plants 916484 Iceland’s Bianda hydroelectric project: monitoring of deformations, rook support and testing of rook anchors in the powerhouse cavern Thorgrimsson, S; Loftsson, M; Jensson, 0 Tunnlg Underground Space Technol I/6, N2, June 1991, P235-239 The major project in Iceland is set in fractured basalt flows, with contact breccias, and interbedded siltstones and sand- stones. The sedimentary layers are sensitive to water content. Finite element analysis was used prior to investigation to gain an initial estimate of stability. Extensive monitoring of defor- mations and displacements was undertaken during excavation and construction stages. Support was by shotcrete and bolts, with a second shotcrete layer where necessary. Pullout tests were carried out on anchors used in the construction of crane beams. 916487 Designed omission of linings in the tunnels for the Lesotho Highlands water project Richards, J A; McKelvey, J G Excavate and Support in tbe 90s, Proc SANCOT Semintw 1990, South Africa, November 1990 P47-55. Publ South Africa: 音乐剧猫 昆虫记读后感 禁毒感想 金色的鱼钩 关于铁凝的作文 放牛班的春天观后感 Goldfields Press, 1990 The geological investigations carried out for the development of water tunnels of the Lesotho Highlands Water Project indi- cated massive rock conditions in the basalts over much of the 45 kilometers of the tunnels. Most of the tunnels were designed as unlined, subject to the satisfaction of certain geotechnical criteria. These design considerations include rock durability, longevity of the initial support, the watertightness of the tunnel, assessment of lengths requiring lining, and the hydraulic capacity of the unlined/lined tunnel. 916488 Effective approaches for construction of Mingtan power cavern Shan; Hsu Cho-Zen Proc 2nd International Conference on Fonndations Wong Shih-Liang; Hsieh Yu- and Tunnels, London, 19-21 September 1989 V2, P171-178. Publ Edinburgh: Engineering Technics Press, 1989 The horseshoe shaped power cavern for the pumped storage scheme will have dimensions 158.7m by 22.7m by 46.5m high. It is being constructed in sandstone rock with prominent bed- ding parallel faults and clay seams. Seam treatment and pre- reinforcement of the cavern roof before excavation have been adopted. Smooth blasting is used to minimise damage. Sup- port is by steel fibre reinforced concrete for flexibility and resistance to seismic loads. Details are given of shotcrete mix, testing, and application. Mines 916485 New Austrian tunnelling record Braun, W Tunn Tunnlg V23, N4, April 1991, P34-35 Tunnelling for the Heinfels hydroelectric scheme in Austria is described. The 3.25km long pressure tunnel was driven in quartz phyllite rock in only 2.5 month, using a Robbins 1014- 250 TBM. Average penetration rate was 52m/day, maximum 104.5m in 22 hours. NATM support was required on only 7.5% of the drive. Lining was 50ram of shotcrete for instant support, plus steel mesh reinforced in situ concrete secondary lining, with steel arches where necessary. 916489 Rheinherg shaft: sinking and lining the freezing shaft (In German) Bittner, F Giuckauf V127, Nll/12, June 1991, 448-458 The sliding shaft lining of the Rheinberg shaft has been designed to withstand closely defined working conditions. The outer lining of concrete blocks serves during sinking to assist the frost casing in supporting rock and water pressure. After thawing, the watertight inner lining supports water pressure, the outer lining supports rock pressure. The inner lining is of reinforced or unreinforced concrete, or steel section, as appropriate. ? 1991 Pergamon Press plc. Reproduction not permitted 音乐剧猫 昆虫记读后感 禁毒感想 金色的鱼钩