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German and Swiss experiences with ground freezing
t06A
Ground freezing 863225 Consolidation of mine fill by freezing Jeremic. M L; Prudhomme. R S CIM Bull V78. .V877. .l,[av 1985. P35-40 The proposed underground application of freezing invob, es the artificial freezing of in-situ backfill bv means of a refrigerated brine solution, circulated through freeze pipes. Findings of this study to date include: uniaxial compressive strength of frozen fill is considerably higher than that of cemented fill (20:1 aggregate to cement): and load deformation characteristics of the frozen fill suggest that a higher ice content results in more brittle failure, and that samples which have initially failed can support up to one-half the ultimate load without additional failure. General evaluation of costs involved suggest that the method could be competitive with hydraulic placement of cemented backfill. Results from laboratory tests indicate that the freezing of backfill is a structurally feasible option. 863226 Three Valleys - the reality of a rolling freeze Hieatt, M J: Draper. A.R Civ Engng, London Nor-Dec 1985. P33-39 The 6kin long. 2.87m diameter Three Valleys Tunnel in Buckinghamshire, UK. was driven using an open faced mechanical shield. Tunnelling became impossible, even using compressed air, when an area with a confusion of sand, silt and clay under a waterhead of 35m was encountered. Initial chemical grouting failed to fully stabilise the soil. and ground freezing with liquid nitrogen was employed. The progress of the project, the ground freezing techniques and their applications are described. 863227 German and Swiss experiences with ground freezing Braun, B Tunn Tunnlg VIT, NI2. Dec 1985. P47-50 Ground freezing is often used in underground construction projects as it adapts to almost any size, shape or depth of project and minimises disturbance to the environment. Three case histories of its application are described. The Born Tunnel, Switzerland was driven through unstable clayey silts with moisture content 10-25%. The Milchbuck Tunnel, also in Switzerland. passed through a moraine section, mostly silty material with inclusions of sandy and gravelly lenses under artesian pressure. Part of the Essen Subway Tunnel, Germany. was constructed below the water table in saturated silts overlying sandstone.
Surface Structures See a~o.863042. 863137, 863217. 863344
863228 Applications of optical-electronic methods to non-destructive testing (In French) Caussignac, J M: Nerriere, J P Bull Liaison Lab Ponts Chaussees NI38. July-Aug 1985. P1518 The adapation of the laser to measure deflections of structures, to simplify particle size analysis and to dynamic holography to study the behaviour of models or structures subject to vibration is briefly described.
863229 Technical circumstances for the re-use of tropical ,soils on ~he TransGal~n Railway (In French) Bo-Edou. F M: Vautrain. J: Tronchc. ,-\ Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia. 11-14 Februao" 1985 V2. P351-359. Pu~l S,z,) Paul,: 8,'a:;/,'n Society ~or Soil A[echanics. 1985 During the construction of the second stage eI the Y,"an~Gabon railway, weathered tropical cta,, soils were encountered which led to problems in excavation, because of their high moisture content, slope stability and earth movement. A geotechnical survey, in the heart of the equatorial forest before the project, allowed some problems to be studied in ad',ance but ~.as insufficient to remove all the t.nkno~ns Further work as the project advanced, and frequent alterations to plans. ,,,,ere necessary. These changes, modifying the geometries of excavations and earthfills and determining the optimum conditions for the use of the local soils, are described.
Geological factors of importance in surface structures 863230 Geological factors in spillway terminal structure design Woodward, R C Engng Geol V22. :VI. Sept 1985. P61-70 Fourteen spillways designed or operated by the Water Resources Commission of New South Wales. Australia, were studied with respect to the geological, topographic and operational factors which influence the type of terminal structure provided. One aspect of spillway ~ o l o g y . rock scour resistance, and the need to provide concrete lining and energy dissipation structures downstream of the spillway crest are dealt with.
Base courses and pavements See also: 863113
863231 Modeling of granular materials in pavements Brown, S F; Pappin, J W Trans Res Rec N1022. 1985. P45-5/ Problems in theoretical modelling of granular materials in pavements are examined using the resilient strain model of Brown and Pappin to describe nonlinear material behaviour and the associated SENOL finite element analysis computer program. Stress conditions, equivalent stiffnesses and failure zones under loading are evaluated for the cases of well graded and poorly graded materials.
863232 Some recent work on the use of locally occurring materials as bases for bituminoas surface low volume roads Grace, H; Higth, D W; Toll, D G Proc 1st International Conference on Geomechanics in Tropical Latcritic and S~rolitic Soils, Brasilia, ! 1-14 February 1985 V2, P295-307. Publ Sao Paulo. Bra=ilian Society for Soil Mechanics. 1985 The use of lateritic and quartzitic gravels as a replacement for crushed stone as a road base material in Kenya is described. The materials behaved better than was originally expected. Field testing showed strength and density increases, attributed to the stress and moisture content cycling in use, which could not be repeated by laboratory testing. Further trials to be
~" 1986 Pergamon Press Ltd. Reproduction not permitted
Ground freezing 863225 Consolidation of mine fill by freezing Jeremic. M L; Prudhomme. R S CIM Bull V78. .V877. .l,[av 1985. P35-40 The proposed underground application of freezing invob, es the artificial freezing of in-situ backfill bv means of a refrigerated brine solution, circulated through freeze pipes. Findings of this study to date include: uniaxial compressive strength of frozen fill is considerably higher than that of cemented fill (20:1 aggregate to cement): and load deformation characteristics of the frozen fill suggest that a higher ice content results in more brittle failure, and that samples which have initially failed can support up to one-half the ultimate load without additional failure. General evaluation of costs involved suggest that the method could be competitive with hydraulic placement of cemented backfill. Results from laboratory tests indicate that the freezing of backfill is a structurally feasible option. 863226 Three Valleys - the reality of a rolling freeze Hieatt, M J: Draper. A.R Civ Engng, London Nor-Dec 1985. P33-39 The 6kin long. 2.87m diameter Three Valleys Tunnel in Buckinghamshire, UK. was driven using an open faced mechanical shield. Tunnelling became impossible, even using compressed air, when an area with a confusion of sand, silt and clay under a waterhead of 35m was encountered. Initial chemical grouting failed to fully stabilise the soil. and ground freezing with liquid nitrogen was employed. The progress of the project, the ground freezing techniques and their applications are described. 863227 German and Swiss experiences with ground freezing Braun, B Tunn Tunnlg VIT, NI2. Dec 1985. P47-50 Ground freezing is often used in underground construction projects as it adapts to almost any size, shape or depth of project and minimises disturbance to the environment. Three case histories of its application are described. The Born Tunnel, Switzerland was driven through unstable clayey silts with moisture content 10-25%. The Milchbuck Tunnel, also in Switzerland. passed through a moraine section, mostly silty material with inclusions of sandy and gravelly lenses under artesian pressure. Part of the Essen Subway Tunnel, Germany. was constructed below the water table in saturated silts overlying sandstone.
Surface Structures See a~o.863042. 863137, 863217. 863344
863228 Applications of optical-electronic methods to non-destructive testing (In French) Caussignac, J M: Nerriere, J P Bull Liaison Lab Ponts Chaussees NI38. July-Aug 1985. P1518 The adapation of the laser to measure deflections of structures, to simplify particle size analysis and to dynamic holography to study the behaviour of models or structures subject to vibration is briefly described.
863229 Technical circumstances for the re-use of tropical ,soils on ~he TransGal~n Railway (In French) Bo-Edou. F M: Vautrain. J: Tronchc. ,-\ Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia. 11-14 Februao" 1985 V2. P351-359. Pu~l S,z,) Paul,: 8,'a:;/,'n Society ~or Soil A[echanics. 1985 During the construction of the second stage eI the Y,"an~Gabon railway, weathered tropical cta,, soils were encountered which led to problems in excavation, because of their high moisture content, slope stability and earth movement. A geotechnical survey, in the heart of the equatorial forest before the project, allowed some problems to be studied in ad',ance but ~.as insufficient to remove all the t.nkno~ns Further work as the project advanced, and frequent alterations to plans. ,,,,ere necessary. These changes, modifying the geometries of excavations and earthfills and determining the optimum conditions for the use of the local soils, are described.
Geological factors of importance in surface structures 863230 Geological factors in spillway terminal structure design Woodward, R C Engng Geol V22. :VI. Sept 1985. P61-70 Fourteen spillways designed or operated by the Water Resources Commission of New South Wales. Australia, were studied with respect to the geological, topographic and operational factors which influence the type of terminal structure provided. One aspect of spillway ~ o l o g y . rock scour resistance, and the need to provide concrete lining and energy dissipation structures downstream of the spillway crest are dealt with.
Base courses and pavements See also: 863113
863231 Modeling of granular materials in pavements Brown, S F; Pappin, J W Trans Res Rec N1022. 1985. P45-5/ Problems in theoretical modelling of granular materials in pavements are examined using the resilient strain model of Brown and Pappin to describe nonlinear material behaviour and the associated SENOL finite element analysis computer program. Stress conditions, equivalent stiffnesses and failure zones under loading are evaluated for the cases of well graded and poorly graded materials.
863232 Some recent work on the use of locally occurring materials as bases for bituminoas surface low volume roads Grace, H; Higth, D W; Toll, D G Proc 1st International Conference on Geomechanics in Tropical Latcritic and S~rolitic Soils, Brasilia, ! 1-14 February 1985 V2, P295-307. Publ Sao Paulo. Bra=ilian Society for Soil Mechanics. 1985 The use of lateritic and quartzitic gravels as a replacement for crushed stone as a road base material in Kenya is described. The materials behaved better than was originally expected. Field testing showed strength and density increases, attributed to the stress and moisture content cycling in use, which could not be repeated by laboratory testing. Further trials to be
~" 1986 Pergamon Press Ltd. Reproduction not permitted