841183 Choice of underground constructions depending on peculiarities of distribution of tectonic stresses in condition of mountainous relief Markov, G A Proc International Symposium on Engineering Geology and Underground Construction, Lisbon, 1983 V1, P3.23-3.35. Publ Lisbon: SPG, 1983 Variation in tectonic stresses under the influence of mountainous relief is examined. A study of the most stable methods of construction for underground workings in mining is then given.
841184 Impact of geological features on design of underground structures of the Rogun hydroelectric scheme Iiushin, V F; Kolichko, A V; Parabuchev, I A Proc International Symposium on Engineering Geology and Underground Construction, Lisbon, 1983 VI, P3.47-3.55. Publ Lisbon: SPG, 1983 The site of the Rogun hydroelectric scheme on the Vakhsh river with a dam rising to 330m and an underground powerhouse, is distinguished by complicated geological engineering conditions: layered rock mass of hard sandstones and aleurolites characterized by high fracturing and high compressive stresses, dissected by active faults. The seismicity of the project site is estimated at 9 grades of the MSK scale. Geological engineering properties of the rock mass governed the layout of the underground structures, means of strengthening and grouting treatment.
Construction methods 841185 Use of joint planes in constructing a large hemispheric- shaped chamber in granitic rock Ege, J R Bull Assoc Engng Geol V20, N3, Aug 1983, P333-338 Design of an underground complex in granitic rock included a hemispheric chamber that required a near-vertical 70ft diameter unsupported smooth face. The construction procedure decided on was to locate a joint plane along which to mine the hemisphere face. Mapping of joints at the surface, in exploratory oriented cores, and in the access shaft and drifts provided joint orientations which were statistically analysed by the equal-area net method. The analysis showed the most probable range of joint orientations compatible with design requirements had a strike of N40 degrees E and dipped 70 degrees NW through vertical to 70 degrees SE. An exploratory drift mined at the proposed hemisphere centre intersected a continuous joint plane bearing N43 degrees E and inclined 74 degrees SE. This plane was used for the hemisphere face.
G r o u n d w a t e r problems 841186 Ground-water pressure relief in shaft sinking Fotheringham, J B; Black, J C Min Engr V143, N263, Aug 1983, P85-91 Two applications of the groundwater pressure relief technique used during the sinking of the Selby Riccail shafts, Yorkshire, UK, are described. The first application is pressure relief in a water-bearing weakly-cemented sandstone during shaft sinking, and the second application used pressure relief in order to carry out backwall grouting at lower pressures than otherwise required.
Hydrogeologicai problems in unlined rock oil storages excavated in crystalline rock masses Pan, B T Proc International Symposium on Engineering Geology and Underground Construction, Lisbon, 1983 VI . PI.323-1.334. Publ Lisbon: SPG, 1983 The characteristics of water bearing, fissure-veined aquifers in crystalline rock masses used for oil and petroleum storage are discussed. A method of determining the lowest groundwater table and identifying the interconnecting fissures is described, based on construction experience in China. It is recommended that the storage site should be located in the rock mass below the long- term average water table or below the regional lowest erosion datum plane.
Influence o f d y n a m i c loads due to e x p l o s i o n s or earthquakes 841188 Surface waves from underground explosions with spalh analysis of elastic and nonlinear source models Day, S M; Rimer, N; Cherry, J T Bull Seismol Soc Am V73, N1, Feb 1983. P247-264 On the basis of a simple equivalent-force model which conserves momentum, it is argued that while spall can enhance explosion surface waves at very short periods, it cannot contribute significantly to the teleseismic surface waves radiated by underground explosions at periods exceeding about 10 seconds. A nonlinear, two-dimensional finite difference simulation of a buried explosion in granite further supports the conclusion that spall cannot contribute to long-period surface waves.
841189 Surface and underground effects of earthquakes (In Italian) Capozza, F Gallerie Grandi Opere Sotterranee V5, N I 3, Sept 1981, P7-24 An advantage of the underground siting of industrial plants in highly seismic areas is the reduced risk of damage from seismic events. Results of 3 experimental studies are summarized: (1) the Tsuraga experimental station, Japan, (2) the ENEL Somplago hydroelectric plant, Italy, and (3) the Shiroytama hydroelectric plant, Japan. It is concluded that a structure based on the surface is subjected to higher stresses than an underground structure in the same rock foundation.
841190 Notes on the effects of the Campania-Lucania Earthquake on 23 November 1980 on surface and on underground hydraulic works located in the epicentrai area (In Italian) Berardi, R; Berenzi, A; Capozza, F Gallerie Grandi Opere Sotterranee VS, NI3, Sept 1981, P2737 Describes the results of investigations in Italy to determine the effects of the earthquake on: (1) diversion works of the S. Mango Sul Calore hydroelectric plant consisting of tunnels and channels, (2) the Muro Lucano arch dam and surge tank and (3) part of the tunnel connecting the Cassano lrpino spring to the Apulia Aqueduct. It is concluded that damage was limited due to good design and accuracy of construction. Underground works were less affected by earthquakes than surface structures and the nature of the soil was important in varying the effects of the earthquake.