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Stabilization of waste ponds at Changi Depot
84A
902155 Fuzzy synthetic judgement for loess foundation collapse Chang, Y Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P207-210. Publ Beijing: International Academic Publishers, 1989 Collapse of loessial soil is affected by many parameters and their interactions, which are not all considered in conventional predictive procedures. A multiple factor synthetic judgement method, based on fuzzy mathematics, is presented to estimate foundation or self weight settlement, which is shown to be more accurate and applicable than normal predictive formulae.
902156 Loess foundation of four embankment dams Chen, Y J Proc International Conference on Engineering Problems of Regional Soils, Beijing, !!-!5 August 1988 P211-214. Publ Beijing: International Academic Publishers, 1989 The properties of loess soils at 4 damsites in China are described and compared. Design measures to limit settlement included excavation and recompaction, prewetting, and use of flexible fill material. Behaviour of one foundation during wetting and of another during operation are reported. Parameters contributing to collapsibility are assessed, together with prewetting methods and comparison of laboratory predicted and observed settlements.
902 ! 57 Collapse phenomena studies by FEM using in situ data Deal, C E; Smith. T Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P215-219. Publ Beifing: International Academic Publishers. 1989 Sinkhole development occurred at an embankment of coarse grained fill over an alluvial fan, where undisturbed sampling was not possible. Extensive in situ measurements were made using cone pcnetrometer and various borehole pressuremeter techniques, before, during, and after wetting-induced collapse. Measured physical and geotechnical properties were used to derive nonlinear material parameters for use in the finite element code FEADAM. Based on this work and observations at surrounding structures, recommendations are made concerning the application of the FEM to collapsible soils.
902159 Prevention of collapse in residual foundation soils of Guri embankment dams Choudry, T Proc 2nd International Conference on Geomechanics in Tropical Soils, Singapore, 12-14 December 1988 V1, P363368. Publ Rotterdam: A A Balkema, 1988 During investigation for the Guri HEP project, some soils were identified as collapsible. One-dimensional consolidation, plate load and triaxial tests confirmed that saprolites in the foundation showed pronounced settlement on wetting. The decision was made to prewet the foundations where soils were susceptible to collapse, as collapse seemed to be due to low degree of saturation and existence of capillary tension in the porous structure of the soil, which is lost on wetting. Observations during flooding and after reservoir filling showed the treatment to have been effective.
902160 Stabilization of waste ponds at Changi Depot Broms, B B; Shirlaw. J N Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 V2, P8.13-8.24. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Abandonment of sand pits excavated in the Old Alluvium of Singapore Island has left ponds filled with soft silty clay. Geotextile was used to increase the bearing capacity of these tailings so fill could be placed for reclamation. Narrow berms were built across the ponds without the bearing capacity being exceeded. As consolidation proceeded, these berms were widened until the whole area was covered. The height of the fill was then increased in stages.
902161 Compressibility and crushability of Campos Basin, Brazil, calcareous sands Almeida, M S S; de Oliveira, W L; Medeiros, C J; Porto, E C Proc 6th International Symposium on Offshore Engineering, Rio de Janeiro, 24-28 August 1987 V6. P215-225. Publ London. Pentech. 1988 Calcareous sands are found in the Campos Basin, where six piled offshore structures will be installed. A brief review of the geology and properties of calcareous sands is first presented. Results of triaxial consolidation and shear tests on the sands, and change of granulometry due to testing are illustrated. Values of parameters from the tests are used in interpretation of three full scale pullout tests on open ended piles driven to 15m depth.
Dynamic properties 902158 Study on collapse sensibility of loess Feng, L C; Feng, K Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P224-226. Publ Beifing: International Academic Publishers. 1989 The general mechanism of collapse is discussed, based on evaluation of one dimensional consolidation with collapse tests on loess. A collapse sensitivity is proposed as the possibility of collapse occurrence and the possibility of collapse development, expressed by a parameter, R, defined as R = K ( I - P s ) , where K is the index of collapsibility and Ps is the initial collapse pressure (saturated residual stress) of the loess. Examination of a large number of test data allows development of a soil classification scheme of collapsibility expressed by R value.
See also." 902187 902162 Displacement approach for generalized Rayleigh waves in layered solid-fluid media Tan, H H Bull Seismol Soc Am V79, N4, Aug 1989, Pl251-1263 A finite element solution is presented for the problem of propagation of Rayleigh waves in a medium of layers of fluid over a layered solid. It uses displacement as the only parameter to describe solid and fluid motions. The elastic coefficient matrix of the fluid is changed from singular to nonsingular using a penalty function method and a selective integration technique. Results obtained agree well with those from analytical solutions.
~i 1990 Pergamon Press plc. Reproduction not permitted
902155 Fuzzy synthetic judgement for loess foundation collapse Chang, Y Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P207-210. Publ Beijing: International Academic Publishers, 1989 Collapse of loessial soil is affected by many parameters and their interactions, which are not all considered in conventional predictive procedures. A multiple factor synthetic judgement method, based on fuzzy mathematics, is presented to estimate foundation or self weight settlement, which is shown to be more accurate and applicable than normal predictive formulae.
902156 Loess foundation of four embankment dams Chen, Y J Proc International Conference on Engineering Problems of Regional Soils, Beijing, !!-!5 August 1988 P211-214. Publ Beijing: International Academic Publishers, 1989 The properties of loess soils at 4 damsites in China are described and compared. Design measures to limit settlement included excavation and recompaction, prewetting, and use of flexible fill material. Behaviour of one foundation during wetting and of another during operation are reported. Parameters contributing to collapsibility are assessed, together with prewetting methods and comparison of laboratory predicted and observed settlements.
902 ! 57 Collapse phenomena studies by FEM using in situ data Deal, C E; Smith. T Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P215-219. Publ Beifing: International Academic Publishers. 1989 Sinkhole development occurred at an embankment of coarse grained fill over an alluvial fan, where undisturbed sampling was not possible. Extensive in situ measurements were made using cone pcnetrometer and various borehole pressuremeter techniques, before, during, and after wetting-induced collapse. Measured physical and geotechnical properties were used to derive nonlinear material parameters for use in the finite element code FEADAM. Based on this work and observations at surrounding structures, recommendations are made concerning the application of the FEM to collapsible soils.
902159 Prevention of collapse in residual foundation soils of Guri embankment dams Choudry, T Proc 2nd International Conference on Geomechanics in Tropical Soils, Singapore, 12-14 December 1988 V1, P363368. Publ Rotterdam: A A Balkema, 1988 During investigation for the Guri HEP project, some soils were identified as collapsible. One-dimensional consolidation, plate load and triaxial tests confirmed that saprolites in the foundation showed pronounced settlement on wetting. The decision was made to prewet the foundations where soils were susceptible to collapse, as collapse seemed to be due to low degree of saturation and existence of capillary tension in the porous structure of the soil, which is lost on wetting. Observations during flooding and after reservoir filling showed the treatment to have been effective.
902160 Stabilization of waste ponds at Changi Depot Broms, B B; Shirlaw. J N Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 V2, P8.13-8.24. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 Abandonment of sand pits excavated in the Old Alluvium of Singapore Island has left ponds filled with soft silty clay. Geotextile was used to increase the bearing capacity of these tailings so fill could be placed for reclamation. Narrow berms were built across the ponds without the bearing capacity being exceeded. As consolidation proceeded, these berms were widened until the whole area was covered. The height of the fill was then increased in stages.
902161 Compressibility and crushability of Campos Basin, Brazil, calcareous sands Almeida, M S S; de Oliveira, W L; Medeiros, C J; Porto, E C Proc 6th International Symposium on Offshore Engineering, Rio de Janeiro, 24-28 August 1987 V6. P215-225. Publ London. Pentech. 1988 Calcareous sands are found in the Campos Basin, where six piled offshore structures will be installed. A brief review of the geology and properties of calcareous sands is first presented. Results of triaxial consolidation and shear tests on the sands, and change of granulometry due to testing are illustrated. Values of parameters from the tests are used in interpretation of three full scale pullout tests on open ended piles driven to 15m depth.
Dynamic properties 902158 Study on collapse sensibility of loess Feng, L C; Feng, K Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P224-226. Publ Beifing: International Academic Publishers. 1989 The general mechanism of collapse is discussed, based on evaluation of one dimensional consolidation with collapse tests on loess. A collapse sensitivity is proposed as the possibility of collapse occurrence and the possibility of collapse development, expressed by a parameter, R, defined as R = K ( I - P s ) , where K is the index of collapsibility and Ps is the initial collapse pressure (saturated residual stress) of the loess. Examination of a large number of test data allows development of a soil classification scheme of collapsibility expressed by R value.
See also." 902187 902162 Displacement approach for generalized Rayleigh waves in layered solid-fluid media Tan, H H Bull Seismol Soc Am V79, N4, Aug 1989, Pl251-1263 A finite element solution is presented for the problem of propagation of Rayleigh waves in a medium of layers of fluid over a layered solid. It uses displacement as the only parameter to describe solid and fluid motions. The elastic coefficient matrix of the fluid is changed from singular to nonsingular using a penalty function method and a selective integration technique. Results obtained agree well with those from analytical solutions.
~i 1990 Pergamon Press plc. Reproduction not permitted