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Roadway design and groundwater
128A 932434 Field evaluation of geonet flow rate (transmissivity) under increasing load Eith, A W; Koerner, R M Geotext Geomem Vll, N4/6, 1992, P489-501
Data are presented from full scale testing of a geonet/geomembrane composite installed at the base of a solid waste landfill site as a leakage detection system. Water was injected at landfill waste heights corresponding to 12, 153, and 311 kPa normal stress. Percentage water recoveries after a 15 hour period were respectively 93.9, 89.6, and 81.2%. Maximum calculated transmissivity drop was about 12%, due to elastic intrusion of the geomembrane into the geonet. Results suggest the drainage system installed is viable under field conditions.
932435 Impacts of bentonite geocomposites on geonet drainage Shaner, K R; Menoff, S D Geotext Geomem Vll, N4/6, 1992, P503-512
The replacement of the naturally compacted clay layer in composite landfill drainage systems by bentonite geocomposites has advantages in availability and installation. Considerable testing of such systems has been undertaken, with a primary aim of limiting intrusion of the bentonite geocomposite into the flow path of underlying geonets. Test methods are briefly reviewed with respect to typical design requirements. Results indicate adequate flow capacity can be maintained. Additional testing will be necessary before complete understanding of all the mechanisms involved can be obtained.
932436 Geosynthetics in erosion control - the principles Carroll, G R; Rodencal, J; Collin, J G Geotext Geomem VII, N4/6, 1992, P523-534
The principles of erosion control are basic and the actions primitive, but modern construction methods and modern synthetic materials have widened the scope for their application. The problem is outlined and the possible solutions discussed: mulch cover, jute and organic blankets, geotextiles, silt control and silt-fences, turf reinforcement mats, and erosion control and prevention mats and blankets. Physical property requirements are assessed and selection criteria described.
932437 Hydrogeologic assessment at Clear Lake Grade Braun, R E; Spillers, P T Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P93-108. Publ Pocatello: Idaho State University, 1992
Road construction through the Snake River Canyon, Idaho, will require a 40m high fill section and a 30m deep cut section. Potential impact to large volume springs in the area has been assessed. Subsurface profile is 0.5-2m of silty sand over 60m of basaltic lava flows then 120m of sedimentary units. Several aquifers have been identified. Computer modelling of the effects of the road cut dewatering using the USGS MODFLOW code indicates possible drawdown of about 300mm in domestic wells within a range of around 0.75km. Springs in the immediate area may be affected, but not the major regional springs. Calculated flow from the cut slopes is about 0.015 cubic m/s.
932438 Roadway design and groundwater Fischer, J A; Fischer, J J; Greene, R W Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P121-135. Publ Pocatello: Idaho State University, 1992
Roadways to a housing development in Middlesex County, New Jersey, showed distress when trafficked by heavy plant and eventually required complete rebuilding during the life of the project. The original design was based on expected occasional perched water table, following inspection of large numbers of test pits and borings. High water levels and even artesian flow within an upper fractured bedrock unit were revealed subsequently. Municipal design procedures did not encompass such possibilities. Remedial activities and redesign are described. Suitable geotechnical input to prevent recurrence of the problem is suggested. 932439 Breaching of an earth dam in the Western Cape by piping Wilson, C; Melis, L Proc Tenth Regional Conference for Africa on Soil Mechanics and Foundation Engineering and the Third International Conference on Tropical and Residual Soils, Maseru, 23-27 September 1991 V1, P301-312. Publ Rotterdam: A A Balkema, 1991 A large erosion tunnel developed through the wall under a 12m high earth dam at its highest section during first filling. The location was adjacent to a concrete encased outlet pipe. It is thought that cracking and/or hydraulic fracture of fill adjacent to the pipe may have caused a concentrated seepage path and piping erosion resulted. Finite element analysis demonstrates the vulnerability of the fill adjacent to the pipe to this type of failure. Piping erosion phenomena are examined, and other possible contributory factors discussed. Preventative measures are described. 932440 Countering potential piping at an earth dam on dispersive soils Watermeyer, C F; Botha, G R; Hall, B E Proc Tenth Regional Conference for Africa on Soil Mec&mics and Foundation Engineering and the Third International Conference on Tropical and Residual Soils, Maseru, 23-27 September 1991 V1, P321-328. Publ Rotterdam: A A Balkema, 1991 The Bloemhoek off-channel storage dam in South Africa is associated with a very high hazard risk in the event of failure. It is a major earth embankment with a central vertical clay core, on colluvium and alluvium over sandstone and shale. Dispersivity of foundation soils and embankment materials has been examined. The effectiveness of the filter downstream of the clay core and cracking of embankment or core due to differential settlement have been assessed. Measures to counter potential piping include a fin-type filter drain to allow safe release of seepage water.
Influence of dynamic loads 932441 Ground borne vibration from piling Whyley, P J; Sarsby, R W Ground Engng II25, N4, May 1992, P32-37
A suggested method for predicting probable vibration resulting from piling operations at any site is presented. It takes into account hammer type, pile type, and (most importantly) soil type. An equation for peak particle velocity is proposed on the basis of theoretical analysis of continua, engineering logic, and
© 1993 Pergamon Press Ltd. Reproduction not permitted
Data are presented from full scale testing of a geonet/geomembrane composite installed at the base of a solid waste landfill site as a leakage detection system. Water was injected at landfill waste heights corresponding to 12, 153, and 311 kPa normal stress. Percentage water recoveries after a 15 hour period were respectively 93.9, 89.6, and 81.2%. Maximum calculated transmissivity drop was about 12%, due to elastic intrusion of the geomembrane into the geonet. Results suggest the drainage system installed is viable under field conditions.
932435 Impacts of bentonite geocomposites on geonet drainage Shaner, K R; Menoff, S D Geotext Geomem Vll, N4/6, 1992, P503-512
The replacement of the naturally compacted clay layer in composite landfill drainage systems by bentonite geocomposites has advantages in availability and installation. Considerable testing of such systems has been undertaken, with a primary aim of limiting intrusion of the bentonite geocomposite into the flow path of underlying geonets. Test methods are briefly reviewed with respect to typical design requirements. Results indicate adequate flow capacity can be maintained. Additional testing will be necessary before complete understanding of all the mechanisms involved can be obtained.
932436 Geosynthetics in erosion control - the principles Carroll, G R; Rodencal, J; Collin, J G Geotext Geomem VII, N4/6, 1992, P523-534
The principles of erosion control are basic and the actions primitive, but modern construction methods and modern synthetic materials have widened the scope for their application. The problem is outlined and the possible solutions discussed: mulch cover, jute and organic blankets, geotextiles, silt control and silt-fences, turf reinforcement mats, and erosion control and prevention mats and blankets. Physical property requirements are assessed and selection criteria described.
932437 Hydrogeologic assessment at Clear Lake Grade Braun, R E; Spillers, P T Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P93-108. Publ Pocatello: Idaho State University, 1992
Road construction through the Snake River Canyon, Idaho, will require a 40m high fill section and a 30m deep cut section. Potential impact to large volume springs in the area has been assessed. Subsurface profile is 0.5-2m of silty sand over 60m of basaltic lava flows then 120m of sedimentary units. Several aquifers have been identified. Computer modelling of the effects of the road cut dewatering using the USGS MODFLOW code indicates possible drawdown of about 300mm in domestic wells within a range of around 0.75km. Springs in the immediate area may be affected, but not the major regional springs. Calculated flow from the cut slopes is about 0.015 cubic m/s.
932438 Roadway design and groundwater Fischer, J A; Fischer, J J; Greene, R W Proc 28th Symposium on Engineering Geology and Geoteclmical Engineering, Boise, 1-3 April 1992 P121-135. Publ Pocatello: Idaho State University, 1992
Roadways to a housing development in Middlesex County, New Jersey, showed distress when trafficked by heavy plant and eventually required complete rebuilding during the life of the project. The original design was based on expected occasional perched water table, following inspection of large numbers of test pits and borings. High water levels and even artesian flow within an upper fractured bedrock unit were revealed subsequently. Municipal design procedures did not encompass such possibilities. Remedial activities and redesign are described. Suitable geotechnical input to prevent recurrence of the problem is suggested. 932439 Breaching of an earth dam in the Western Cape by piping Wilson, C; Melis, L Proc Tenth Regional Conference for Africa on Soil Mechanics and Foundation Engineering and the Third International Conference on Tropical and Residual Soils, Maseru, 23-27 September 1991 V1, P301-312. Publ Rotterdam: A A Balkema, 1991 A large erosion tunnel developed through the wall under a 12m high earth dam at its highest section during first filling. The location was adjacent to a concrete encased outlet pipe. It is thought that cracking and/or hydraulic fracture of fill adjacent to the pipe may have caused a concentrated seepage path and piping erosion resulted. Finite element analysis demonstrates the vulnerability of the fill adjacent to the pipe to this type of failure. Piping erosion phenomena are examined, and other possible contributory factors discussed. Preventative measures are described. 932440 Countering potential piping at an earth dam on dispersive soils Watermeyer, C F; Botha, G R; Hall, B E Proc Tenth Regional Conference for Africa on Soil Mec&mics and Foundation Engineering and the Third International Conference on Tropical and Residual Soils, Maseru, 23-27 September 1991 V1, P321-328. Publ Rotterdam: A A Balkema, 1991 The Bloemhoek off-channel storage dam in South Africa is associated with a very high hazard risk in the event of failure. It is a major earth embankment with a central vertical clay core, on colluvium and alluvium over sandstone and shale. Dispersivity of foundation soils and embankment materials has been examined. The effectiveness of the filter downstream of the clay core and cracking of embankment or core due to differential settlement have been assessed. Measures to counter potential piping include a fin-type filter drain to allow safe release of seepage water.
Influence of dynamic loads 932441 Ground borne vibration from piling Whyley, P J; Sarsby, R W Ground Engng II25, N4, May 1992, P32-37
A suggested method for predicting probable vibration resulting from piling operations at any site is presented. It takes into account hammer type, pile type, and (most importantly) soil type. An equation for peak particle velocity is proposed on the basis of theoretical analysis of continua, engineering logic, and
© 1993 Pergamon Press Ltd. Reproduction not permitted