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Reassessment of the causes of the Carsington embankment failure
186A 923366 Behavionr of statically loaded piles embedded in a soil with cyclically vary~g effective stress Hanna, T H; AI-Jumaily, F A Proc NLqth Damdk,-European Conference on Soil Moclmics amt Fmmdatioa Emgineeriq, Bmlapest, 2-5 October 1990 1'211-217. Publ Budapest: Akademiai Kiado, 1990
92337O Bearing capacity determination of deep foundations in Bratisinva and other towns Matys, M; Werdenich, K Proc Ninth Datmbe-Ewopean Conference on Soil Meclumics and Fmmdation Eagi~eriag, Bmdapest, 2-5 October 1990 1'259-264. Publ Budapest: Akademiai Kiado, 1990
An instrumented model pile was installed in dry sand in a test chamber. Constant axial load was maintained on the pile, while effective stress in the soil mass was varied by applying a surcharge load to the surface using a special loading plate. Distribution of axial load and pile friction and pile tip movement were monitored during the cycling of soil effective stress. Load distribution around the pile changes during the cycling. Reasons for this are examined. Bearing capacity in compression increases during cycfing, but pullout resistance is little affected.
Many large structures are founded on piles in Bratislava. The underlying soils are predominantly medium compact to loose alluvial deposits and neogene sediments. Two methods used to assess bearing capacity are described. The first involves loading the pile using a specially designed cylindrical tank, which is held in place by anchors, and filled in stages with water to apply load. The second is used where transport of the tank is difficult. Bearing capacity is calculated according to a formula by Menard (1975) with the shaft friction contribution evaluated from pressuremeter test data.
923367 Drilled pier fonndation practice for highrlae buildings in Montreal, Cmugin Ladanyi, B; Bensoussan, A; Castongnay, J; Tommasel, A M Proc Ninth Damabe-Europetm Conference on Soil Meelta~s amt Foundation F a ~ e r i a g , Bmlapest, 2-5 October 1990 P239-246. Publ Budapest: Akademiai Kiado, 1990 Much of urban Montreal is underlain by thick glacial till over sub-horizontally bedded shales and limestone at depths 1315m. Drilled piled foundations, socketed into bedrock, are used for most tall buildings with basements. The pile design codes, considering load partitioning between shaft and base, and where each of these is applied are described. Two case studies are presented where bedrock RQDs were 0% and 2555% respectively, and the applicability of the designs adopted is discussed. 923368 New foundation method of motorway bridge on the River Danube Lakatos, E; Apathy, E; Encsy, B; Hlatky, K; Gyorgy, P Proc Ninth Danbe.European Conference on Soil M e c k a ~ s and Fomulation ~ g , Bmdapest, 2-5 October 1990 P247-251. Publ Budapest: Akademiai Kiado, 1990 The new Danube bridge has three piers situated in the riverbed. Traditional and modem methods of construction were considered before a novel technique was chosen. Following dredging of the riverbed, it was deepened by 0.5m to make a flat area for a precast concrete bottom member. Bored, cast in place piles were constructed using guide rings in the bottom member to aid location. An upper precast member placed on the pile heads takes a concrete slab on which the piers are built.
923371 Underpinning on expansive soils - a ease history Uriel, A O; Ortuno, L; Puebla, J Proc 6tk Imermuiomd Confereoce on Expamive Soils, New DelM, 24 Nocember-4 December 1987 V2, P611-614. Publ Rotterdam: A A Balkema, 1991 Severe damage was exhibited at a structure founded at depth 2.5m in high plasticity marly clay with swelling pressures up 875kPa. Trees have desiccated the ground, causing settlement, and, following their removal, expansive movements are expected. Underpinning is the chosen remedial measure, with a concrete beam used to transmit structural loads to deep concrete piers, the high contact pressures minimising movement. The piers are at depth 5m, below the most desiccated zone. A gap is left between soil surface and beam base to accommodate swelling movement.
Dams and embankments See also: 923188 923372 Constructions of multi-purpose dams in Japan In: Rock Moclmaics ia Japan, Volm~ VI P36-39. Pubi Tokyo: Japanese Committe for ISRM, 1991 Over 300 dams, mainly concrete gravity structures, have been completed in Japan for flood control and water supply, and some 400 more are planned. The scarcity of tight bedrock for foundations has led to requirement of rigorous site investigation. The typical case of the Miyagase Dam is described, where 5300m of geophysical prospecting was supplemented by 16 in situ deformation and 25 in situ shear tests, core drilling (87 holes), permeability tests (73 holes), and 19 exploratory adits. The roller compacted cement for dams (RCD) construction method is favoured on grounds of quality, economy, and safety.
923369 Analysis of drilled piers aettlemeats with non-linear deformability of the soils Malyshev, M V Proc Nimk Daube-Em'opean Conference on Soil M e e k a ~ s and Fomulation F ~ i ~ ' i ~ g , Bmlqest, 2-5 October 1990 1'253-258. Publ Budapest: Akademiai Kiado, 1990
923373 ReassesmmM of the causes of the Candngton emlmnkmont failure Rowe, P W Geoteelmiqnc ;/41, N3, Sept 1991, P395-421
An analysis is presented for the load-settlement behaviour of piles which includes both the end bearing and shaft friction components of bearing capacity. Settlement against load is evaluated both for the initial linear period where the soil behaves elastically and in the region of plastic deformation. The point of onset of plastic deformation, where bearing capacity is effectively lost, is examined.
Further data on the 1984 Carsington failure have been made available for analysis. They indicate an unusual mechanism of articulated shears commencing within the base of the mudstone fills along shear planes built in at the centre of the valley during early stages of construction. Initiation and procedure of the process, culminating in collapse at the side dragging the centre into failure, are explained. The basic cause can be
© 1992 Pergamon Press Ltd. Reproduction not permitted
187A attributed to use of smooth wheeled rollers on wet, plastic clay fill without effective scarification. Built in shears were formed along these smooth planes during subsequent stages of construction.
excessive. Remedial measures included excavation of tunnels in the slate beneath the toe and constructing a concrete plug and grouting of trap rock.
923374 Evaluation of failure of embankment during heightening Bauduin, C; Molenkamp, F Geoteelmique V41, N3, Sept 1991, P423-435
923378 Design considerations for heightening of existing dams Narayana, V V B; Haridas, C; Joshi, A B
The inner slope of a clay flood embankment on the MeuseRhine delta failed just after completion of broadening and heightening. Classical slope stability analysis at the last loading stage had indicated a factor of safety about 1.15. The geotechnical profile of the site and monitored data during construction are described. Differences between classical assumed behaviour and actual behaviour are examined. The major factor leading to failure was the higher than assumed pore pressures generated during construction.
923375 Foundation treatment at the Tadami dam site lnt Water Power Dam Constr V43, N i l , Nov 1991, P35-36 The Tadami rockfill dam on the Agano river, Japan, is founded on 21m of alluvium over bedrock. Excavation down to bedrock was considered uneconomic. The alluvial deposits of gravel, sand, and silt are dense and interlocked, and a bentonite concrete diaphragm wall was chosen as the foundation treatment. This plastic concrete has mechanical properties compatible with both foundation and dam during its working life. Construction and performance are described.
923376 Design of a tailings disposal facility for the Samatosom Mine, British Columbia Hawley, P M; Stewart, A F Proc 2rid International Symposium on Mine PinnMslg and Equipment Selection,Calgary, 7-9 No~ember 1990 P433-440. Publ Rotterdam: A ,4 Balkema, 1990 A tailings impoundment with ultimate capacity of 800,000 cubic m is planned for the recently commissioned Samatosum Mine. The initial impoundment is a 20m high, homogeneous till dam, with crest length 225m, which will be raised to ultimate height 30m by downstream construction. Site selection, engineering geology, selection of construction method, and water balance are discussed. Construction of intermediate and ultimate embankments, stability and settlement, seepage, and monitoring in this environmentally sensitive area were taken into account at the design stage.
923377 Settlement analysis of Lakhwar Dam foundations Arora, B M; Yadav, S K Proc l ~ m Geoteclmical Conference, 1989, Geoteclmiques of Problematic Soils amt Rocks, gisakimpntnam, 14-16 December 1989 V1, P491-494. Pubi New Delhi: Sarita Prakashan, 1989 The foundation rocks of the 240m high concrete gravity dam consist of slates, quartzites, and limestone, forming the southern limb of a major syncline, intruded by a number of minor basic trap bodies. Foliated slates with low deformation modulus exist beneath the dam toe and vertical differential settlements with respect to existing foundation rocks have been
Proc lmtian Geoteelmical Conference, 1989, Geoteelmiqncs of Problematic Soils and Rocks, VisakhapntMm, 14-16 December 1989 VI, P495-499. Publ New Delhi: Sarita Prakashan, 1989 The raising of an earth dam, part of the composite Som Kamala Amba dam in Rajasthan, is described. Minimising of rehandling was the aim. The central area was extended by an inclined core and the inclined sand filter turned towards downstream. The rock toe was extended in width and the toe drain shifted to maintain internal drainage. Stone pitching on the filter was made thicker and reinforced. Foundation rock was examined and considered adequate. Because of problems where it met the earth dam, the masonry core wall was converted to an additional non-overflow block. Composite dams require special care at the design stage if future heightening is envisaged.
Hydraulic structures 923379 Methods to ensure water tightness for a dry dock founded on fissured reck at Visakhapatmun fishing harbour Sastry, S V L S N; Murty, R N; Rao, T S P Proc Indian Geoteclmical Conference, 1989, Geoteclmiqncs of Problematic Soils and Rocks, YIsakimpatum, 14-16 December 1989 V1, P509-512. Publ New Delhi: Sarita Prakashan, 1989 The 65m long by 21m wide by 6m deep (low tide) structure was founded on fissured and fractured rock at shallow depth, which created problems of potential water ingress. The overcome this, an extensive pressure grouting program was carried out. Curtain grouting beneath the walls and blanket grouting beneath the floor of the structure, plus installation of drainage systems and instrumentation to monitor water flow are described.
92338O l.inin~= and stabillsntion of slopes for channels in Black Cotton soils Datye, K R Proc 6th lmernationai Conference on Expansive Sot'Is, New DelM, 24 No~mber-4 December 1987 V2, P626-629. Pubi Rotterdam: A A Balkema, 1991 Linings for hydraulic structures in expansive Black Cotton soils are discussed. CNS layers can be used to provide a surface load to prevent swelling and to minimise moisture transport. When CNS soils are not available, linings using geogrids are suggested. The cells of the grid can be filled with nonplastic granular materials, stabilised soil blocks, or thin concrete blocks. A bitumenised surface coating minimises moisture ingress whilst a sand wick drain beneath the grid allows drainage of the soil mass. Cost comparisons are presented.
© 1992 Pergamon Press Ltd. Reproduction not permitted
92337O Bearing capacity determination of deep foundations in Bratisinva and other towns Matys, M; Werdenich, K Proc Ninth Datmbe-Ewopean Conference on Soil Meclumics and Fmmdation Eagi~eriag, Bmdapest, 2-5 October 1990 1'259-264. Publ Budapest: Akademiai Kiado, 1990
An instrumented model pile was installed in dry sand in a test chamber. Constant axial load was maintained on the pile, while effective stress in the soil mass was varied by applying a surcharge load to the surface using a special loading plate. Distribution of axial load and pile friction and pile tip movement were monitored during the cycling of soil effective stress. Load distribution around the pile changes during the cycling. Reasons for this are examined. Bearing capacity in compression increases during cycfing, but pullout resistance is little affected.
Many large structures are founded on piles in Bratislava. The underlying soils are predominantly medium compact to loose alluvial deposits and neogene sediments. Two methods used to assess bearing capacity are described. The first involves loading the pile using a specially designed cylindrical tank, which is held in place by anchors, and filled in stages with water to apply load. The second is used where transport of the tank is difficult. Bearing capacity is calculated according to a formula by Menard (1975) with the shaft friction contribution evaluated from pressuremeter test data.
923367 Drilled pier fonndation practice for highrlae buildings in Montreal, Cmugin Ladanyi, B; Bensoussan, A; Castongnay, J; Tommasel, A M Proc Ninth Damabe-Europetm Conference on Soil Meelta~s amt Foundation F a ~ e r i a g , Bmlapest, 2-5 October 1990 P239-246. Publ Budapest: Akademiai Kiado, 1990 Much of urban Montreal is underlain by thick glacial till over sub-horizontally bedded shales and limestone at depths 1315m. Drilled piled foundations, socketed into bedrock, are used for most tall buildings with basements. The pile design codes, considering load partitioning between shaft and base, and where each of these is applied are described. Two case studies are presented where bedrock RQDs were 0% and 2555% respectively, and the applicability of the designs adopted is discussed. 923368 New foundation method of motorway bridge on the River Danube Lakatos, E; Apathy, E; Encsy, B; Hlatky, K; Gyorgy, P Proc Ninth Danbe.European Conference on Soil M e c k a ~ s and Fomulation ~ g , Bmdapest, 2-5 October 1990 P247-251. Publ Budapest: Akademiai Kiado, 1990 The new Danube bridge has three piers situated in the riverbed. Traditional and modem methods of construction were considered before a novel technique was chosen. Following dredging of the riverbed, it was deepened by 0.5m to make a flat area for a precast concrete bottom member. Bored, cast in place piles were constructed using guide rings in the bottom member to aid location. An upper precast member placed on the pile heads takes a concrete slab on which the piers are built.
923371 Underpinning on expansive soils - a ease history Uriel, A O; Ortuno, L; Puebla, J Proc 6tk Imermuiomd Confereoce on Expamive Soils, New DelM, 24 Nocember-4 December 1987 V2, P611-614. Publ Rotterdam: A A Balkema, 1991 Severe damage was exhibited at a structure founded at depth 2.5m in high plasticity marly clay with swelling pressures up 875kPa. Trees have desiccated the ground, causing settlement, and, following their removal, expansive movements are expected. Underpinning is the chosen remedial measure, with a concrete beam used to transmit structural loads to deep concrete piers, the high contact pressures minimising movement. The piers are at depth 5m, below the most desiccated zone. A gap is left between soil surface and beam base to accommodate swelling movement.
Dams and embankments See also: 923188 923372 Constructions of multi-purpose dams in Japan In: Rock Moclmaics ia Japan, Volm~ VI P36-39. Pubi Tokyo: Japanese Committe for ISRM, 1991 Over 300 dams, mainly concrete gravity structures, have been completed in Japan for flood control and water supply, and some 400 more are planned. The scarcity of tight bedrock for foundations has led to requirement of rigorous site investigation. The typical case of the Miyagase Dam is described, where 5300m of geophysical prospecting was supplemented by 16 in situ deformation and 25 in situ shear tests, core drilling (87 holes), permeability tests (73 holes), and 19 exploratory adits. The roller compacted cement for dams (RCD) construction method is favoured on grounds of quality, economy, and safety.
923369 Analysis of drilled piers aettlemeats with non-linear deformability of the soils Malyshev, M V Proc Nimk Daube-Em'opean Conference on Soil M e e k a ~ s and Fomulation F ~ i ~ ' i ~ g , Bmlqest, 2-5 October 1990 1'253-258. Publ Budapest: Akademiai Kiado, 1990
923373 ReassesmmM of the causes of the Candngton emlmnkmont failure Rowe, P W Geoteelmiqnc ;/41, N3, Sept 1991, P395-421
An analysis is presented for the load-settlement behaviour of piles which includes both the end bearing and shaft friction components of bearing capacity. Settlement against load is evaluated both for the initial linear period where the soil behaves elastically and in the region of plastic deformation. The point of onset of plastic deformation, where bearing capacity is effectively lost, is examined.
Further data on the 1984 Carsington failure have been made available for analysis. They indicate an unusual mechanism of articulated shears commencing within the base of the mudstone fills along shear planes built in at the centre of the valley during early stages of construction. Initiation and procedure of the process, culminating in collapse at the side dragging the centre into failure, are explained. The basic cause can be
© 1992 Pergamon Press Ltd. Reproduction not permitted
187A attributed to use of smooth wheeled rollers on wet, plastic clay fill without effective scarification. Built in shears were formed along these smooth planes during subsequent stages of construction.
excessive. Remedial measures included excavation of tunnels in the slate beneath the toe and constructing a concrete plug and grouting of trap rock.
923374 Evaluation of failure of embankment during heightening Bauduin, C; Molenkamp, F Geoteelmique V41, N3, Sept 1991, P423-435
923378 Design considerations for heightening of existing dams Narayana, V V B; Haridas, C; Joshi, A B
The inner slope of a clay flood embankment on the MeuseRhine delta failed just after completion of broadening and heightening. Classical slope stability analysis at the last loading stage had indicated a factor of safety about 1.15. The geotechnical profile of the site and monitored data during construction are described. Differences between classical assumed behaviour and actual behaviour are examined. The major factor leading to failure was the higher than assumed pore pressures generated during construction.
923375 Foundation treatment at the Tadami dam site lnt Water Power Dam Constr V43, N i l , Nov 1991, P35-36 The Tadami rockfill dam on the Agano river, Japan, is founded on 21m of alluvium over bedrock. Excavation down to bedrock was considered uneconomic. The alluvial deposits of gravel, sand, and silt are dense and interlocked, and a bentonite concrete diaphragm wall was chosen as the foundation treatment. This plastic concrete has mechanical properties compatible with both foundation and dam during its working life. Construction and performance are described.
923376 Design of a tailings disposal facility for the Samatosom Mine, British Columbia Hawley, P M; Stewart, A F Proc 2rid International Symposium on Mine PinnMslg and Equipment Selection,Calgary, 7-9 No~ember 1990 P433-440. Publ Rotterdam: A ,4 Balkema, 1990 A tailings impoundment with ultimate capacity of 800,000 cubic m is planned for the recently commissioned Samatosum Mine. The initial impoundment is a 20m high, homogeneous till dam, with crest length 225m, which will be raised to ultimate height 30m by downstream construction. Site selection, engineering geology, selection of construction method, and water balance are discussed. Construction of intermediate and ultimate embankments, stability and settlement, seepage, and monitoring in this environmentally sensitive area were taken into account at the design stage.
923377 Settlement analysis of Lakhwar Dam foundations Arora, B M; Yadav, S K Proc l ~ m Geoteclmical Conference, 1989, Geoteclmiques of Problematic Soils amt Rocks, gisakimpntnam, 14-16 December 1989 V1, P491-494. Pubi New Delhi: Sarita Prakashan, 1989 The foundation rocks of the 240m high concrete gravity dam consist of slates, quartzites, and limestone, forming the southern limb of a major syncline, intruded by a number of minor basic trap bodies. Foliated slates with low deformation modulus exist beneath the dam toe and vertical differential settlements with respect to existing foundation rocks have been
Proc lmtian Geoteelmical Conference, 1989, Geoteelmiqncs of Problematic Soils and Rocks, VisakhapntMm, 14-16 December 1989 VI, P495-499. Publ New Delhi: Sarita Prakashan, 1989 The raising of an earth dam, part of the composite Som Kamala Amba dam in Rajasthan, is described. Minimising of rehandling was the aim. The central area was extended by an inclined core and the inclined sand filter turned towards downstream. The rock toe was extended in width and the toe drain shifted to maintain internal drainage. Stone pitching on the filter was made thicker and reinforced. Foundation rock was examined and considered adequate. Because of problems where it met the earth dam, the masonry core wall was converted to an additional non-overflow block. Composite dams require special care at the design stage if future heightening is envisaged.
Hydraulic structures 923379 Methods to ensure water tightness for a dry dock founded on fissured reck at Visakhapatmun fishing harbour Sastry, S V L S N; Murty, R N; Rao, T S P Proc Indian Geoteclmical Conference, 1989, Geoteclmiqncs of Problematic Soils and Rocks, YIsakimpatum, 14-16 December 1989 V1, P509-512. Publ New Delhi: Sarita Prakashan, 1989 The 65m long by 21m wide by 6m deep (low tide) structure was founded on fissured and fractured rock at shallow depth, which created problems of potential water ingress. The overcome this, an extensive pressure grouting program was carried out. Curtain grouting beneath the walls and blanket grouting beneath the floor of the structure, plus installation of drainage systems and instrumentation to monitor water flow are described.
92338O l.inin~= and stabillsntion of slopes for channels in Black Cotton soils Datye, K R Proc 6th lmernationai Conference on Expansive Sot'Is, New DelM, 24 No~mber-4 December 1987 V2, P626-629. Pubi Rotterdam: A A Balkema, 1991 Linings for hydraulic structures in expansive Black Cotton soils are discussed. CNS layers can be used to provide a surface load to prevent swelling and to minimise moisture transport. When CNS soils are not available, linings using geogrids are suggested. The cells of the grid can be filled with nonplastic granular materials, stabilised soil blocks, or thin concrete blocks. A bitumenised surface coating minimises moisture ingress whilst a sand wick drain beneath the grid allows drainage of the soil mass. Cost comparisons are presented.
© 1992 Pergamon Press Ltd. Reproduction not permitted