- Email: [email protected]
Effective stress analysis of the stability of embankments on soft soils
155A
Proper planning of preloading requires time predictions that cannot be obtained reliably from laboratory oedameter tests. Time forecasts should be based on f i e l d permeability tests or test fills. The settlement versus log time curve of preloading can assume a variety of shapes, deperzling on the geometry add permeability of sand-silt contained within the consolidating clay. Experience indicates that three types of curves are recurrent: (i) Sshaped, (2) bi-linear with increase in slope, ar~ (3) linear. The first kind shows that settlement is about completed, for (2) and (3), approximate equations are proposed for predicting the settlement of the permanent structure from settlements observed during preloading. Examples are presented from two cons%ruction sites in Greece. Auth. 835198 DESIGN CAPACITY OF SLURRIED MINERAL WASTE PONDS Carrier, W D; Brc~well, L G; Somo~yi, F J Geotech Er~ng Div ASCE, VI09, ~ , May 1983, P6 99-716 This paper stmmmrlzes existing consolidation data for various slurried mineral wastes: specifically, CCmlressibility amd permeability. It describes the state-of-the-art in field and laboratory tests for measuring the comsolidation properties of these very soft sediments. It briefly reviews computer programs that have been written to analyse finite strain consolidation. A design methodology is developed in detail for rapid calculation of storage calmnity of disposal ponds under a variety of conditions. Finally, a methodology for determining preliminary design consolidation properties is described that is based on the Atterberg !~.~ts of the waste material. Auth. 835199 HERE'S AN UPDATE ON FIFELINE ANCHGRIND Webb, B C Oil Gas J, VSI, ~20, 16 May 1983, ~ 9 - 8 3 A procedure for designing a pipeline mechamlcal anchoring system is presented. Major fs2t(rs to be considered are soil shear s t r e r ~ , size ar~ service of pipeline, soil densities, ditch conditions and construction techniques. 835200 S E ~ LIMITATIONS FOR CYLINDRICAL sc~:~:,STORAGE TANMS Rosenberg, P; Journeaux, N L Can Geotech J, rig, N3, AUg 1982, P232-238 Includes a review of settlements that have caused malfunction or failure of steel storage tanks, and relates the data to movement limitation criteria preser~aly used in foundation practice. Based on data from the literature, a limiting range of movement is st~ested. This evaluates the permissible settlement that can be sustained without causing mslfur2tion or failure.
Dams and embankments See also: 835290
835201 SLAB-JACKING AT TAEBELA DAM, PAKISTAN Brt~e, D A; Joyee, G M Ground Engng, VI6, N3, Alm'll 1983, P35-~2 This paper describes a major slab-Jacking programme conducted recently at Tarbela Dam, Pakistan. Some 375eu m of mainly cement-bentonite grouts were injected through 1302 hole~ ~!rilled
through 39 of the concrete panels forming the protective apron to the upstream clay blamket material of the auxiliary spillway. The purpose of the work was to restore full contact between the panels and th e blanket, and to llft the slabs to their original attitudes following localised erosion of the clay. Data are provided on the design, control and effects of the slabJacking together with fluid and set properties of the grouts employed. Auth.
835202 ROCK GROUTING AND WATER TESTING AT KIELDER DAM, N
O ~ Bruce, D A; Millmore, J P Q J Engng Geol, VI6, NI, 1983, P13-29
In ~'der to test the effectiveness of a cement grout curtain formed in the Narth Abutment bedrock of the Kielder Dam, Northumberland, UK, to control underseepage, a series of pre- and postgrouting Lugeon water tests were conducted. The test method was found to be practical and superic~ to the short duration, single pressure tests cca~only used. Safe g r o u t i ~ pressures for the curtain were selected following 2 hydrofracture tests using similar methods. 835203 A55 ~ MELYN SLIP AND REMEDIAL WORKS: A CASE STUDY Siva Subramanian, A; Carr, R W Q J Engng Geol, V16, NI, 1983, P53-63 A case history of the A55 Pwll Melyn Slip is presented. The 7 year old road embankment failed by downslope translational movement following exceptionally high rainfall : fluvioglaclal deposits were considered the main source of the high pa~e water pressures responsible for the failure. A deep cut-off drain was constructed upslope and a free-drainlng granular layer at the base of the embankment in order to prevent future pore water pressure buildup. The original road, carrying d l v = ~ e d traffic, was supported by a temporary, rock anchored, sheet-pile retaining wall during the r~nedial work.
835204. EROSION IN RELATION TO FILTER DESIGN CRITERIA IN EARTH DAMS Arularmmdanj K; Perry, E B J Geotech E r ~ Div ASCE, VI09, NGTS, May 1983, ?682-698 Erodibility characteristics of the core material and the associated clogging tendency of the filter matrix are the major factors influencing the successful Performance of a filter in a dam with a vertical clay core. The erodlbility characteristics of the core material have been quantified in terms of the p a r ~ e r 'critical shear stress'. The performance of clay core dams has been examined with respect to piping: a clear relationship exists between critical shear stress and the piping behsviour. A ~rocedure for the evaluation of filter performance with respect to core material erodibility is proposed. 42 refs.
835205 CORRECTED FIELD VANE ~ FOR E M 2 ~ M E N T DESIGN. TECHNICAL NOTE Azzouz, A S; Bali@h, M M; Ladd s C C J Geoteah E r ~ Div ASCE, VI09, NOT2, May 1983, FT30-734 Three-dimensional stability analyses of 18 case histories of embankment failures are performed and a new correction factor estimatirg the actual in situ undrained shear strength from the measured field vane strength data is
156A
proposed. The analyses show that end effects generally increase the conventional plane strsin factor of safety by approximately i0 per cent. B35206 EFFECTIVE STRESS ANALYSIS OF THE ~OTABILITY OF EMBANENENTS ON SOFT SOILS Pilot, G; Trak, B; La Rochelle, P Can Geoteeh J, V!9, N4, Nov 1962, I~33-450 Stability ark?~lyses of. 4 test embankments were perfc~nned by means of the effective stress method using in situ pore pressure measurements during failure. The factors Of safety obtained are compared with results from total stress analyses. 45 refs. 135207 GEOTECHNICAL PROBL~NS RELATED TO THE BUILDING OF A TAILINGS DAM ON SENSITIVE VARVED CLAY Capozio, N U; Otttmet, J M; Dupuls, M M Can Geotech J, V19, ~ , Nov 1982, I~72-482 A case history Of a 7m high tailings dam founded on varved clay sedimented in a glacial lake near Matagaml, Quebac, Canada. Loz~t1~dinal cracks which appeared in the crest of the dam led to 3 geotechnlcal investigations carried out in 1978, 1980 amd 1981. The results of borings, in situ vane tests, amd stability analyses, toge~her with rem~lial meast;res urgertaken or planned are presented.
8352o8 D2~ ON ~UATERNARY LIMESTONE AND CALCAREOUS SAND FORMATION Okamoto, R; Miura, S; Takeahlta, T Bull Int Assoc Engr~ Geol, N~4, Dec 1961, I%3-68 (Paper to Sympos~mm on Engineering Geological Problems of Construction on Soluble Rocks, Istar~ul, 14-18 Sept 1961) Okukubi Dam, Okinawa Island, is the first concrete gravity dam to be built on the Guaternary limestone and calcareous sand formation in Japan. The paper de~rlbes the geological amd hydrological conditions at the dam site. The lower part of the abutment is composed of alternations of PBlaeogene sandstone amd shale, the upper part is composed of silt, fine sand, calcareous sand amd limestone. Grouting at both abutments plus a cutoff wall at the right abutment are platted as foundation treatment. 835209 PRACTICAL EXPERIENCE IN ENGINEerING-GEOlOGICAL INVESTIGATIONS FOR HYDRAULIC CONSTRUCTION ON THE SOLUBLE ROCKS IN THE USSR ~olokov, L A; Paraboutchev, I A Bull Int Assoc E r ~ Geol, N24, Dec 1981, 1%9-73 (Paper to Symposium on Engineering Geological Problems of Construction on Soluble Pocks, Istanbul, 14-18 Sept 1981) Soluble rocks present problems for hydrotechnlcal construction: in carborates slow solution is further complicated by solution channels and rock weakening and in evaporltes intensive salt solution and mass deformation are possible during dam operation. Improva~ent of er~ineeriz~geological methods of karst imv~sti~'atio~ modern technical equipment and increasing erEineering experience contribute to effective and economic measures in dam construction. Protection from karst action is schieved by s e e l ~ e control measures or by structt~al adaptation. In ÷~he USSR several large hydroelectric plants are successfully operating in regions of intensive karst develoument.
835210 STABILITY ANALYSIS WITH THE ~'~:CTIVE STRESS METHOD FOR EMBAI~KMENTS CONSTRUcI'~D ON AN ~ILUVIAL MARINE CLAY Har~awa, H; Kishida, T; Matsuda, E Soils Fomld, V22, N3, Sept 1982, P32-46 A stability analysis using the effective stress method for 5 embankments constructed on alluvial marine clay at or near failure is reported. A method to determine the internal angle of friction anl the cohesion, in terms Of the effective stress, for use in the analysis is proposed. A comparison is also made of the predicted and measured excess pore water pressure beneath an embankment. 835211 CONSOLIDATION OF AN ELASTOPLASTIC SOIL (IN FRENCH) Magnan, J P; Belkeziz, A Rev Fr Geotech, NI9, May 1982, P39-49 The finite element l~ogram ROSALIE was used to calculate the consolidation of soft foundation soils under an experimemtal embankment. Three mc~lels were used fc~ the soil skeleton: isotroPic linear elasticity, anisotroplc linear elasticity, and isotroplc strain hardening elastoplasticity (a modified Cam Clay model). Comparison with measured results showed that the ar~sotroplc elasticity and elastoplasticity models gave good results.
Foundations See also: 835250 835212 BUILDING ON EXPANSIVE CLAYS Berkovltch, I Civ E~gog, Lomdon, April 1983, P37-38 Reports on a Joint British and Jordanian proJect to investigate damage to buildings in Jordan due to movements Of the foundations which are based on expansive clays. A study of affected buildings and a labcratcry study s h c ~ d the dams4~ to Be the result of swelling amd shrinking Of the clay. Lc~ (one storey) blzLldings amd buildings near trees were found to Be more susceptible to damage. 835213 EUROCCDES AND THE GEOTECHNICAL ENGINEER Bolton, M D Grotml ~ , v16, N3, April 1983, P17-21,31 Discusses the forthcoming Eurocode EC7 on Fourdations whose draft Became available in January 1983. The flexibility of such a code of practice, to allow for the engineer's Judgement, and the IToposed starzlardization of procedures to make all ~_mber countries compatible are particularly considered. 835214 EUROCODE EC7 - THE PREPARATION OF A 'BASE DOCUMENT' Simpson, B Grourd Emgng, VI6, N3, April 1983, P27-31 Discusses the current state of the proposed Euroccde EC7 on foundations which will consist of i0 chapters. Chapters i, 2, 4 and 6 have been substantially developed: these relate to general principles, safety and serviceability, geotechnlcal data snd spread foundations. Points of debate arising from the draft are noted.
Proper planning of preloading requires time predictions that cannot be obtained reliably from laboratory oedameter tests. Time forecasts should be based on f i e l d permeability tests or test fills. The settlement versus log time curve of preloading can assume a variety of shapes, deperzling on the geometry add permeability of sand-silt contained within the consolidating clay. Experience indicates that three types of curves are recurrent: (i) Sshaped, (2) bi-linear with increase in slope, ar~ (3) linear. The first kind shows that settlement is about completed, for (2) and (3), approximate equations are proposed for predicting the settlement of the permanent structure from settlements observed during preloading. Examples are presented from two cons%ruction sites in Greece. Auth. 835198 DESIGN CAPACITY OF SLURRIED MINERAL WASTE PONDS Carrier, W D; Brc~well, L G; Somo~yi, F J Geotech Er~ng Div ASCE, VI09, ~ , May 1983, P6 99-716 This paper stmmmrlzes existing consolidation data for various slurried mineral wastes: specifically, CCmlressibility amd permeability. It describes the state-of-the-art in field and laboratory tests for measuring the comsolidation properties of these very soft sediments. It briefly reviews computer programs that have been written to analyse finite strain consolidation. A design methodology is developed in detail for rapid calculation of storage calmnity of disposal ponds under a variety of conditions. Finally, a methodology for determining preliminary design consolidation properties is described that is based on the Atterberg !~.~ts of the waste material. Auth. 835199 HERE'S AN UPDATE ON FIFELINE ANCHGRIND Webb, B C Oil Gas J, VSI, ~20, 16 May 1983, ~ 9 - 8 3 A procedure for designing a pipeline mechamlcal anchoring system is presented. Major fs2t(rs to be considered are soil shear s t r e r ~ , size ar~ service of pipeline, soil densities, ditch conditions and construction techniques. 835200 S E ~ LIMITATIONS FOR CYLINDRICAL sc~:~:,STORAGE TANMS Rosenberg, P; Journeaux, N L Can Geotech J, rig, N3, AUg 1982, P232-238 Includes a review of settlements that have caused malfunction or failure of steel storage tanks, and relates the data to movement limitation criteria preser~aly used in foundation practice. Based on data from the literature, a limiting range of movement is st~ested. This evaluates the permissible settlement that can be sustained without causing mslfur2tion or failure.
Dams and embankments See also: 835290
835201 SLAB-JACKING AT TAEBELA DAM, PAKISTAN Brt~e, D A; Joyee, G M Ground Engng, VI6, N3, Alm'll 1983, P35-~2 This paper describes a major slab-Jacking programme conducted recently at Tarbela Dam, Pakistan. Some 375eu m of mainly cement-bentonite grouts were injected through 1302 hole~ ~!rilled
through 39 of the concrete panels forming the protective apron to the upstream clay blamket material of the auxiliary spillway. The purpose of the work was to restore full contact between the panels and th e blanket, and to llft the slabs to their original attitudes following localised erosion of the clay. Data are provided on the design, control and effects of the slabJacking together with fluid and set properties of the grouts employed. Auth.
835202 ROCK GROUTING AND WATER TESTING AT KIELDER DAM, N
O ~ Bruce, D A; Millmore, J P Q J Engng Geol, VI6, NI, 1983, P13-29
In ~'der to test the effectiveness of a cement grout curtain formed in the Narth Abutment bedrock of the Kielder Dam, Northumberland, UK, to control underseepage, a series of pre- and postgrouting Lugeon water tests were conducted. The test method was found to be practical and superic~ to the short duration, single pressure tests cca~only used. Safe g r o u t i ~ pressures for the curtain were selected following 2 hydrofracture tests using similar methods. 835203 A55 ~ MELYN SLIP AND REMEDIAL WORKS: A CASE STUDY Siva Subramanian, A; Carr, R W Q J Engng Geol, V16, NI, 1983, P53-63 A case history of the A55 Pwll Melyn Slip is presented. The 7 year old road embankment failed by downslope translational movement following exceptionally high rainfall : fluvioglaclal deposits were considered the main source of the high pa~e water pressures responsible for the failure. A deep cut-off drain was constructed upslope and a free-drainlng granular layer at the base of the embankment in order to prevent future pore water pressure buildup. The original road, carrying d l v = ~ e d traffic, was supported by a temporary, rock anchored, sheet-pile retaining wall during the r~nedial work.
835204. EROSION IN RELATION TO FILTER DESIGN CRITERIA IN EARTH DAMS Arularmmdanj K; Perry, E B J Geotech E r ~ Div ASCE, VI09, NGTS, May 1983, ?682-698 Erodibility characteristics of the core material and the associated clogging tendency of the filter matrix are the major factors influencing the successful Performance of a filter in a dam with a vertical clay core. The erodlbility characteristics of the core material have been quantified in terms of the p a r ~ e r 'critical shear stress'. The performance of clay core dams has been examined with respect to piping: a clear relationship exists between critical shear stress and the piping behsviour. A ~rocedure for the evaluation of filter performance with respect to core material erodibility is proposed. 42 refs.
835205 CORRECTED FIELD VANE ~ FOR E M 2 ~ M E N T DESIGN. TECHNICAL NOTE Azzouz, A S; Bali@h, M M; Ladd s C C J Geoteah E r ~ Div ASCE, VI09, NOT2, May 1983, FT30-734 Three-dimensional stability analyses of 18 case histories of embankment failures are performed and a new correction factor estimatirg the actual in situ undrained shear strength from the measured field vane strength data is
156A
proposed. The analyses show that end effects generally increase the conventional plane strsin factor of safety by approximately i0 per cent. B35206 EFFECTIVE STRESS ANALYSIS OF THE ~OTABILITY OF EMBANENENTS ON SOFT SOILS Pilot, G; Trak, B; La Rochelle, P Can Geoteeh J, V!9, N4, Nov 1962, I~33-450 Stability ark?~lyses of. 4 test embankments were perfc~nned by means of the effective stress method using in situ pore pressure measurements during failure. The factors Of safety obtained are compared with results from total stress analyses. 45 refs. 135207 GEOTECHNICAL PROBL~NS RELATED TO THE BUILDING OF A TAILINGS DAM ON SENSITIVE VARVED CLAY Capozio, N U; Otttmet, J M; Dupuls, M M Can Geotech J, V19, ~ , Nov 1982, I~72-482 A case history Of a 7m high tailings dam founded on varved clay sedimented in a glacial lake near Matagaml, Quebac, Canada. Loz~t1~dinal cracks which appeared in the crest of the dam led to 3 geotechnlcal investigations carried out in 1978, 1980 amd 1981. The results of borings, in situ vane tests, amd stability analyses, toge~her with rem~lial meast;res urgertaken or planned are presented.
8352o8 D2~ ON ~UATERNARY LIMESTONE AND CALCAREOUS SAND FORMATION Okamoto, R; Miura, S; Takeahlta, T Bull Int Assoc Engr~ Geol, N~4, Dec 1961, I%3-68 (Paper to Sympos~mm on Engineering Geological Problems of Construction on Soluble Rocks, Istar~ul, 14-18 Sept 1961) Okukubi Dam, Okinawa Island, is the first concrete gravity dam to be built on the Guaternary limestone and calcareous sand formation in Japan. The paper de~rlbes the geological amd hydrological conditions at the dam site. The lower part of the abutment is composed of alternations of PBlaeogene sandstone amd shale, the upper part is composed of silt, fine sand, calcareous sand amd limestone. Grouting at both abutments plus a cutoff wall at the right abutment are platted as foundation treatment. 835209 PRACTICAL EXPERIENCE IN ENGINEerING-GEOlOGICAL INVESTIGATIONS FOR HYDRAULIC CONSTRUCTION ON THE SOLUBLE ROCKS IN THE USSR ~olokov, L A; Paraboutchev, I A Bull Int Assoc E r ~ Geol, N24, Dec 1981, 1%9-73 (Paper to Symposium on Engineering Geological Problems of Construction on Soluble Pocks, Istanbul, 14-18 Sept 1981) Soluble rocks present problems for hydrotechnlcal construction: in carborates slow solution is further complicated by solution channels and rock weakening and in evaporltes intensive salt solution and mass deformation are possible during dam operation. Improva~ent of er~ineeriz~geological methods of karst imv~sti~'atio~ modern technical equipment and increasing erEineering experience contribute to effective and economic measures in dam construction. Protection from karst action is schieved by s e e l ~ e control measures or by structt~al adaptation. In ÷~he USSR several large hydroelectric plants are successfully operating in regions of intensive karst develoument.
835210 STABILITY ANALYSIS WITH THE ~'~:CTIVE STRESS METHOD FOR EMBAI~KMENTS CONSTRUcI'~D ON AN ~ILUVIAL MARINE CLAY Har~awa, H; Kishida, T; Matsuda, E Soils Fomld, V22, N3, Sept 1982, P32-46 A stability analysis using the effective stress method for 5 embankments constructed on alluvial marine clay at or near failure is reported. A method to determine the internal angle of friction anl the cohesion, in terms Of the effective stress, for use in the analysis is proposed. A comparison is also made of the predicted and measured excess pore water pressure beneath an embankment. 835211 CONSOLIDATION OF AN ELASTOPLASTIC SOIL (IN FRENCH) Magnan, J P; Belkeziz, A Rev Fr Geotech, NI9, May 1982, P39-49 The finite element l~ogram ROSALIE was used to calculate the consolidation of soft foundation soils under an experimemtal embankment. Three mc~lels were used fc~ the soil skeleton: isotroPic linear elasticity, anisotroplc linear elasticity, and isotroplc strain hardening elastoplasticity (a modified Cam Clay model). Comparison with measured results showed that the ar~sotroplc elasticity and elastoplasticity models gave good results.
Foundations See also: 835250 835212 BUILDING ON EXPANSIVE CLAYS Berkovltch, I Civ E~gog, Lomdon, April 1983, P37-38 Reports on a Joint British and Jordanian proJect to investigate damage to buildings in Jordan due to movements Of the foundations which are based on expansive clays. A study of affected buildings and a labcratcry study s h c ~ d the dams4~ to Be the result of swelling amd shrinking Of the clay. Lc~ (one storey) blzLldings amd buildings near trees were found to Be more susceptible to damage. 835213 EUROCCDES AND THE GEOTECHNICAL ENGINEER Bolton, M D Grotml ~ , v16, N3, April 1983, P17-21,31 Discusses the forthcoming Eurocode EC7 on Fourdations whose draft Became available in January 1983. The flexibility of such a code of practice, to allow for the engineer's Judgement, and the IToposed starzlardization of procedures to make all ~_mber countries compatible are particularly considered. 835214 EUROCODE EC7 - THE PREPARATION OF A 'BASE DOCUMENT' Simpson, B Grourd Emgng, VI6, N3, April 1983, P27-31 Discusses the current state of the proposed Euroccde EC7 on foundations which will consist of i0 chapters. Chapters i, 2, 4 and 6 have been substantially developed: these relate to general principles, safety and serviceability, geotechnlcal data snd spread foundations. Points of debate arising from the draft are noted.