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Aquifer recharge enhanced with rubber dam installations
34A
SURFACE STRUCTURES:DAMS AND EMBANKMENTS
aftershocks expected immediately after a major earthquake. (Authors) 961271 Severn slip team R. Byles, New Civil Engineer (NCE), June(Suppl.), 1995, pp 49-50. Balfour Beatty is using a Wirtgen slipformer to lay two 14 km twin lane and hard shoulder concrete reinforced carriageways for the approach roads to the Second Severn Crossing. The concrete will be laid on a lean-mix sub-base in single full width passes of 600 m per day. The slipformer will work in conjunction with a refurbished concrete spreader. Constant and consistent supply of concrete is vital if slipforming production targets are to be achieved. (J.M.McLaughlin) 961272 Derby's new course L. Russell, New Civil Engineer (NCE), June(Supp.), 1995, pp 4-6,8. Construction of the 24 kin, £109.5 M Derby Southern Bypass scheme is described. It is the largest road scheme under construction in the UK. The three lane dual carfiageway incorporates 27 main bridges, 28 large culverts, four accommodation bridges, and two railway bridges. Design emphasis is on earthworks and bridgeworks. The main earthworks are briefly described. Ground improvement techniques and drainage works are also described. (J.M.McLaughlin) 961273 Holding water L. Russell, New Civil Engineer (NCE), June(Suppl.), 1995, p25,26,28. Describes in detail construction of the 4.7 km Blackwater Valley dual carriageway route. It incorporates deep water resistant troughs, a canal aqueduct, and crosses a network of lagoons. A major diversion of the River Blackwater had to be carried out, and existing lake area (old gravel workings) have been backfilled or crossed by causeways. Construction of an underpass section and the aqueduct are detailed. Environmental considerations were important, and substantial planting and landscaping has been carried out. (J.M.McLaughlin)
Foundations and piles 961274 Critical depth: how it came into being and why it does not exist B. H. Fellenius & A. A. Altaee, Proceedings - ICE." Geotechnical Engineering, 113(2), 1995, pp 107-111. This paper discusses the fallacy of the concept of the critical depth. The fallacy is due to neglecting residual loads in fullscale tests and stress-scale effects at model-scales, made measured load distribution appear linear below a certain 'critical' depth. It is concluded that interpretations of results made in the light of the critical depth concept can result in unsafe designs. (Authors) 961275 Analysis of foundation deformations beneath the Synerude tailings dyke J. Alencar, N. R. Morgenstern & D. H. Chan, Canadian Geotectmical Journal, 31(6), 1994, pp 868-884. The paper presents the results obtained in the finite element simulation of 8 years of construction of a section of Syncrude's tailings dyke, which is located in northern Alberta and has been used to store oil sand mining waste. The site investigation for the construction of this dyke indicated that a region of the foundation contained a presheared, overconsolidated clay shale lying practically horizontal at about 20 m depth. Significant horizontal displacements have occurred along this layer. Displacements calculated by the effective stress analyses are in very good agreement with the measured
values, and the combination of parameters necessary to reach those results are within the acc~table range of variability for each material involved, based on laboratory test results. The interpolation of the pore pressures based on the piezometer measurements and their incorporation into the analyses as known quantities at each stage of the loading process was found to be relatively simple and efficient. (from Authors) 961276 First application of electro-osmosis to improve friction pile capacity - three decades later V. Milligan, Proceedings - ICE: Geotechnical Engineering, 113(2), 1995, pp 112-116. The problem of founding the Big Pic River Bridge on some 100 m of soft varved clay and loose silt deposits is described. Due to the presence of excess hydrostatic head at depth, the capacity of long friction piles was markedly less than that of short piles; consequently, it was decided to found the structure on short, steel H-section friction piles within the upper clay and to apply electro-osmotic treatment. The overall effect of the electro-osmosis was markedly to increase the pile capacity. Further tests have since been carried out over the past 33 years to assess the permanence of the increase in pile capacity. No reduction in the load bearing capacity of the piles has been measured over this period and recorded settlement of the bridge foundations has been minimal. (Author) 961277 Behaviour of flexible piles in layered d a y s under eccentric and inclined loads V. V. R. N. Sastry & G. G. Meyerhof, Canadian Geotechnical Journal, 32(3), 1995, pp 387-396. The lateral soil pressures, bending moments, pile displacements at the ground surface, and the bearing capacity of instrumented vertical single flexible model piles in a layered clay system consisting of medium clay overlying soft clay under vertical eccentric and central inclined loads have been investigated. The results of these load tests are compared with theoretical estimates based on the concept of the effective embedment depth of equivalent rigid piles for ultimate and elastic cases. Reasonable agreement has been found between the observed and predicted behaviour of flexible piles. (from Authors) 961278 Effect of pile driving on adjacent piles in clay H. G. Poulos, Cam~dian Geotechnical Journal, 31(6), 1994, pp 856-867. This paper describes the results of a theoretical analysis of the bending moments and axial forces developed in a pile due to driving of an adjacent pile in clay. The analysis uses approximate distributions of horizontal and vertical soil movements caused by pile driving, developed from a 'strainpath' analysis, together with inferences from model pile test data. An examination is made of various factors that may influence the induced bending moments and forces. For a number of published case histories comparisons are made between theoretical and measured axial and laterial pile movements. In general, satisfactory agreement is found. (from Author)
Dams and embankments 961279 Aquifer recharge enhanced with rubber dam installations M. R. Markus, C. A. Thompson & M. Ulukaya, Water Engineering & Management, 142(1), 1995, pp 37-40. Two inflatable rubber dams with bypass facilities to divert fiver flows to off-river recharge basins have been constructed on the Santa Ana River in California, USA. The dams capture excess flow that would otherwise be lost to the ocean. (J.M.McLaughlin)
SURFACE STRUCTURES:DAMS AND EMBANKMENTS
aftershocks expected immediately after a major earthquake. (Authors) 961271 Severn slip team R. Byles, New Civil Engineer (NCE), June(Suppl.), 1995, pp 49-50. Balfour Beatty is using a Wirtgen slipformer to lay two 14 km twin lane and hard shoulder concrete reinforced carriageways for the approach roads to the Second Severn Crossing. The concrete will be laid on a lean-mix sub-base in single full width passes of 600 m per day. The slipformer will work in conjunction with a refurbished concrete spreader. Constant and consistent supply of concrete is vital if slipforming production targets are to be achieved. (J.M.McLaughlin) 961272 Derby's new course L. Russell, New Civil Engineer (NCE), June(Supp.), 1995, pp 4-6,8. Construction of the 24 kin, £109.5 M Derby Southern Bypass scheme is described. It is the largest road scheme under construction in the UK. The three lane dual carfiageway incorporates 27 main bridges, 28 large culverts, four accommodation bridges, and two railway bridges. Design emphasis is on earthworks and bridgeworks. The main earthworks are briefly described. Ground improvement techniques and drainage works are also described. (J.M.McLaughlin) 961273 Holding water L. Russell, New Civil Engineer (NCE), June(Suppl.), 1995, p25,26,28. Describes in detail construction of the 4.7 km Blackwater Valley dual carriageway route. It incorporates deep water resistant troughs, a canal aqueduct, and crosses a network of lagoons. A major diversion of the River Blackwater had to be carried out, and existing lake area (old gravel workings) have been backfilled or crossed by causeways. Construction of an underpass section and the aqueduct are detailed. Environmental considerations were important, and substantial planting and landscaping has been carried out. (J.M.McLaughlin)
Foundations and piles 961274 Critical depth: how it came into being and why it does not exist B. H. Fellenius & A. A. Altaee, Proceedings - ICE." Geotechnical Engineering, 113(2), 1995, pp 107-111. This paper discusses the fallacy of the concept of the critical depth. The fallacy is due to neglecting residual loads in fullscale tests and stress-scale effects at model-scales, made measured load distribution appear linear below a certain 'critical' depth. It is concluded that interpretations of results made in the light of the critical depth concept can result in unsafe designs. (Authors) 961275 Analysis of foundation deformations beneath the Synerude tailings dyke J. Alencar, N. R. Morgenstern & D. H. Chan, Canadian Geotectmical Journal, 31(6), 1994, pp 868-884. The paper presents the results obtained in the finite element simulation of 8 years of construction of a section of Syncrude's tailings dyke, which is located in northern Alberta and has been used to store oil sand mining waste. The site investigation for the construction of this dyke indicated that a region of the foundation contained a presheared, overconsolidated clay shale lying practically horizontal at about 20 m depth. Significant horizontal displacements have occurred along this layer. Displacements calculated by the effective stress analyses are in very good agreement with the measured
values, and the combination of parameters necessary to reach those results are within the acc~table range of variability for each material involved, based on laboratory test results. The interpolation of the pore pressures based on the piezometer measurements and their incorporation into the analyses as known quantities at each stage of the loading process was found to be relatively simple and efficient. (from Authors) 961276 First application of electro-osmosis to improve friction pile capacity - three decades later V. Milligan, Proceedings - ICE: Geotechnical Engineering, 113(2), 1995, pp 112-116. The problem of founding the Big Pic River Bridge on some 100 m of soft varved clay and loose silt deposits is described. Due to the presence of excess hydrostatic head at depth, the capacity of long friction piles was markedly less than that of short piles; consequently, it was decided to found the structure on short, steel H-section friction piles within the upper clay and to apply electro-osmotic treatment. The overall effect of the electro-osmosis was markedly to increase the pile capacity. Further tests have since been carried out over the past 33 years to assess the permanence of the increase in pile capacity. No reduction in the load bearing capacity of the piles has been measured over this period and recorded settlement of the bridge foundations has been minimal. (Author) 961277 Behaviour of flexible piles in layered d a y s under eccentric and inclined loads V. V. R. N. Sastry & G. G. Meyerhof, Canadian Geotechnical Journal, 32(3), 1995, pp 387-396. The lateral soil pressures, bending moments, pile displacements at the ground surface, and the bearing capacity of instrumented vertical single flexible model piles in a layered clay system consisting of medium clay overlying soft clay under vertical eccentric and central inclined loads have been investigated. The results of these load tests are compared with theoretical estimates based on the concept of the effective embedment depth of equivalent rigid piles for ultimate and elastic cases. Reasonable agreement has been found between the observed and predicted behaviour of flexible piles. (from Authors) 961278 Effect of pile driving on adjacent piles in clay H. G. Poulos, Cam~dian Geotechnical Journal, 31(6), 1994, pp 856-867. This paper describes the results of a theoretical analysis of the bending moments and axial forces developed in a pile due to driving of an adjacent pile in clay. The analysis uses approximate distributions of horizontal and vertical soil movements caused by pile driving, developed from a 'strainpath' analysis, together with inferences from model pile test data. An examination is made of various factors that may influence the induced bending moments and forces. For a number of published case histories comparisons are made between theoretical and measured axial and laterial pile movements. In general, satisfactory agreement is found. (from Author)
Dams and embankments 961279 Aquifer recharge enhanced with rubber dam installations M. R. Markus, C. A. Thompson & M. Ulukaya, Water Engineering & Management, 142(1), 1995, pp 37-40. Two inflatable rubber dams with bypass facilities to divert fiver flows to off-river recharge basins have been constructed on the Santa Ana River in California, USA. The dams capture excess flow that would otherwise be lost to the ocean. (J.M.McLaughlin)