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Assessing deep-seated dissolution-subsidence hazards at radioactive-waste repository sites in bedded salt
251A the face, and top heading were used before roadheader excavation. In better ground, the arch slot was cut with a giant chainsaw-like machine, concreted, and the face excavated by rippers. Support and waterproofing are described. Optimum solutions to problems, if full knowledge were available at the time of decision making, are discussed.
subject to certain loading assumptions. Field data from the project will clarify the assumptions and allow further development of this construction technique.
904432 Raise boring applications for colliery shafts Odell, P L; Kotze, A I Proc SANCOT Seminar on Mecbanised Underground Excavation, November 1989 t'27-37. Publ South Africa: Goldfields Press, 1989
904436 Assessing deep-seated dissolution-subsidence hazards at radioactive-waste repository sites in bedded salt Davies, P B Engng Geol V27. NI-4. Dec 1989. P467-487
Various techniques that are available for shaft construction where raise boring forms a part are discussed. The effect of rock quality and rock structures on the choice of construction method is also examined. Costs of different construction methods are examined and compared. A case study based on two ventilation shafts at Bosjesspruit Colliery in South Africa is presented. Different lining techniques in use are summarised. 9O4433 Precast concrete segmental lined shafts McBean, R J S Proc Conference on Shaft Engineering, Harrogate, 5-7 June 1989 P297.308. Publ London: IMM. 1989 Developments in reinforced concrete segmental linings for shafts are discussed. Four main construction methods, underpinning (good cohesive soils with little or no water), underpinning with compressed air (water bearing ground), shaft shield (non-cohesive ground sandwiched between cohesive soil) and caisson sinking (unstable ground) are described. Design improvements, including corbels, soft eye openings, waterproofing, sealing gaskets, and development of hydrophillic neoprene for seals are outlined. 904434 Shaft sinking at Sikfors power station Najder, T; Olsson, P Proc Conference on Shaft Engineering, Harrogute, 5-7 June 1989 P325-330. Publ London: IMM. 1989 Construction of a shaft by caisson excavation through dense silty moraine is described. The groundwater level was lowered to 3m above the bedrock by use of filter drains. Initial problems with the caisson cracking were overcome by strengthening. During the final phase of shaft sinking, problems occurred due to inclination of the caisson as it was heavier on one side, coinciding with slightly higher groundwater levels and lower strength soil materials. This was remedied by use of backfilling and jacks to apply pressure. The final 3m in wet soil was excavated without freezing. 904435 Design of an underground station in the deep site with abundant groundwater Miyagawa, F; lmamura, M; Suga, T Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI, P245-251. Publ Rotterdam: A A Balkema. 1988 A construction method suggested for a metro station in saturated sand, clayey soil, and gravel is presented. The primary cut and cover for the station hall is followed by ground improvement and shield driving of the platform tunnels. Dewatering, secondary cut and cover hall excavation, and excavation between the shield section come next. The backfilling of the surface layer and excavation linking cut and cover and shield sections complete the project. Stresses and displacements have been calculated using finite element analysis, but
Groundwater problems
Deep seated salt dissolution has led to subsidence in many salt bearing sedimentary basins. The dissolution-subsidence process can breach the hydrologic integrity of a thick salt unit, and must be considered as a potential hazard for repositories in bedded salt masses. Field and analytical studies have been used to examine this phenomenon. Ductile or brittle subsidence may result, depending on speed of dissolution of the salt. Hazard estimation begins with identification of existing dissolution-subsidence features, and evaluating potential for further activity. 904437 Groundwater conditions in underground openings in sedimentary rocks Lee, C F; Raven, K G; Heystee, J J Proc 15th Canadian Rock Mechanics Symposium, Rock Engineering for Underground Excavations, 3-4 October 1988 P61-71. Publ Toronto: University of Toronto, 1988 Groundwater inflow conditions in underground openings were surveyed using field observations and borehole hydraulic tests at a large number of mines across the USA and Canada. Wet and dry conditions were identified in relation to site geology. Dolomite, dolomitic limestone, and sandstone rocks were often associated with major inflows, massive shaly limestones were often dry. Argillaceous rocks generally show lower variability in hydraulic conductivity than crystalline rocks, and should not be totally overlooked when considering sites for underground waste disposal. 904438 Influence of water on the stability of a deep tunnel (In French) Huergo, P J; Nakhle, A Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI. P177-184. Publ Rotterdam: A A Balkema, 1988 A theoretical approach is developed to the problem of tunnelling beneath the water table on the basis of compatibility between stress and deformation, and which takes into account hydraulic gradient (originally proposed by Fazio and Ribacchi, 1981). Results are illustrated for the case of a tunnel in a flysh massive under differing mechanical and hydrological conditions. 904439 Empirical approach to prediction of groundwater in tunneling Liang Jinhuo; Sun Guangzhong Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI, P!93-197. Publ Rotterdam: A A Balkema. 1988 A study of permeability of geological structures is used as a basis for a predictive model of groundwater inflow into tunnels. General permeability of fault types is first discussed. Water containing capacity of different rocks and, in particular, problems related to limestone and their relation to geological structures are examined. Flow charts are presented which form the base of a simple empirical estimation of inflow rates.
1990 Pergamon Press plc. Reproduction not permitted
subject to certain loading assumptions. Field data from the project will clarify the assumptions and allow further development of this construction technique.
904432 Raise boring applications for colliery shafts Odell, P L; Kotze, A I Proc SANCOT Seminar on Mecbanised Underground Excavation, November 1989 t'27-37. Publ South Africa: Goldfields Press, 1989
904436 Assessing deep-seated dissolution-subsidence hazards at radioactive-waste repository sites in bedded salt Davies, P B Engng Geol V27. NI-4. Dec 1989. P467-487
Various techniques that are available for shaft construction where raise boring forms a part are discussed. The effect of rock quality and rock structures on the choice of construction method is also examined. Costs of different construction methods are examined and compared. A case study based on two ventilation shafts at Bosjesspruit Colliery in South Africa is presented. Different lining techniques in use are summarised. 9O4433 Precast concrete segmental lined shafts McBean, R J S Proc Conference on Shaft Engineering, Harrogate, 5-7 June 1989 P297.308. Publ London: IMM. 1989 Developments in reinforced concrete segmental linings for shafts are discussed. Four main construction methods, underpinning (good cohesive soils with little or no water), underpinning with compressed air (water bearing ground), shaft shield (non-cohesive ground sandwiched between cohesive soil) and caisson sinking (unstable ground) are described. Design improvements, including corbels, soft eye openings, waterproofing, sealing gaskets, and development of hydrophillic neoprene for seals are outlined. 904434 Shaft sinking at Sikfors power station Najder, T; Olsson, P Proc Conference on Shaft Engineering, Harrogute, 5-7 June 1989 P325-330. Publ London: IMM. 1989 Construction of a shaft by caisson excavation through dense silty moraine is described. The groundwater level was lowered to 3m above the bedrock by use of filter drains. Initial problems with the caisson cracking were overcome by strengthening. During the final phase of shaft sinking, problems occurred due to inclination of the caisson as it was heavier on one side, coinciding with slightly higher groundwater levels and lower strength soil materials. This was remedied by use of backfilling and jacks to apply pressure. The final 3m in wet soil was excavated without freezing. 904435 Design of an underground station in the deep site with abundant groundwater Miyagawa, F; lmamura, M; Suga, T Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI, P245-251. Publ Rotterdam: A A Balkema. 1988 A construction method suggested for a metro station in saturated sand, clayey soil, and gravel is presented. The primary cut and cover for the station hall is followed by ground improvement and shield driving of the platform tunnels. Dewatering, secondary cut and cover hall excavation, and excavation between the shield section come next. The backfilling of the surface layer and excavation linking cut and cover and shield sections complete the project. Stresses and displacements have been calculated using finite element analysis, but
Groundwater problems
Deep seated salt dissolution has led to subsidence in many salt bearing sedimentary basins. The dissolution-subsidence process can breach the hydrologic integrity of a thick salt unit, and must be considered as a potential hazard for repositories in bedded salt masses. Field and analytical studies have been used to examine this phenomenon. Ductile or brittle subsidence may result, depending on speed of dissolution of the salt. Hazard estimation begins with identification of existing dissolution-subsidence features, and evaluating potential for further activity. 904437 Groundwater conditions in underground openings in sedimentary rocks Lee, C F; Raven, K G; Heystee, J J Proc 15th Canadian Rock Mechanics Symposium, Rock Engineering for Underground Excavations, 3-4 October 1988 P61-71. Publ Toronto: University of Toronto, 1988 Groundwater inflow conditions in underground openings were surveyed using field observations and borehole hydraulic tests at a large number of mines across the USA and Canada. Wet and dry conditions were identified in relation to site geology. Dolomite, dolomitic limestone, and sandstone rocks were often associated with major inflows, massive shaly limestones were often dry. Argillaceous rocks generally show lower variability in hydraulic conductivity than crystalline rocks, and should not be totally overlooked when considering sites for underground waste disposal. 904438 Influence of water on the stability of a deep tunnel (In French) Huergo, P J; Nakhle, A Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI. P177-184. Publ Rotterdam: A A Balkema, 1988 A theoretical approach is developed to the problem of tunnelling beneath the water table on the basis of compatibility between stress and deformation, and which takes into account hydraulic gradient (originally proposed by Fazio and Ribacchi, 1981). Results are illustrated for the case of a tunnel in a flysh massive under differing mechanical and hydrological conditions. 904439 Empirical approach to prediction of groundwater in tunneling Liang Jinhuo; Sun Guangzhong Proc International Congress on Tunnels and Water, Madrid, 15-18 June 1988 VI, P!93-197. Publ Rotterdam: A A Balkema. 1988 A study of permeability of geological structures is used as a basis for a predictive model of groundwater inflow into tunnels. General permeability of fault types is first discussed. Water containing capacity of different rocks and, in particular, problems related to limestone and their relation to geological structures are examined. Flow charts are presented which form the base of a simple empirical estimation of inflow rates.
1990 Pergamon Press plc. Reproduction not permitted