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matrix flow
22A
Compressibility, swelling and consolidation See also." 941358
941169 Field and laboratory experience with the use of strip drains in organic soils Koda, E; Szymanski, A; Wolski, W Can Geotech J V30, N2, April 1993, P308-318 The performance of vertical strip drains to speed consolidation of peat and gyttja during stage construction of embankments has been examined. Effective increase in bearing capacity was seen, but a significant decrease in drainage capacity occurred during construction, depending on the nature of the drain filter material. This was further studied in the laboratory. The decrease did not significantly affect consolidation rate. Buckling of the drains had little effect on drainage capacity. The use of vertical drains reduced horizontal displacements below the embankment during construction.
941170 Geotechnical properties of dune sands in Kuwait AI-Sanad, H A; Ismael, N F; Nayfeh, A J Engng Geoi V34, N1/2, May 1993, P45-52 Dune sands from four sites in Kuwait have been characterised in the laboratory. Grain size distribution, strength, and compressibility were measured and compaction tests carried out. The sands are fine, poorly graded silica sands with almost no fines. Compacted sands show high strength and low compressibility and are not sensitive to saturation or wetting and so are suitable materials for embankment fill or backfill.
941171 Compression of collapsed loess: studies on bonded and unbonded soils Feda, J; Bohac, J; Herle, I Engng Geoi V34, N1/2, May 1993, P95-103 Compression of bonded (collapsible) and debonded (collapsed) Sedlec loess has been studied in the laboratory. Oedometric and triaxial compression curves yield identical compression indices. Intrinsic and semilogarithmic compression lines compare well with data on the debonded soils. Reconstituted samples will develop a bonded structure with age, as do natural samples. As reconstituted samples have a much lower initial porosity than the natural loess, these aged and bonded soils do not collapse when the bonding is destroyed by loading.
941172 Swelling pressure behavior under controlled suction. Technical note Habib, S A; Karube, D Geotech Test J V16, N2, June 1993, P271-275 One dimensional consolidation tests carried out in a modified floating ring oedometer under conditions of controlled suction with simultaneous measurement of vertical and lateral swelling pressures are described. Results show both pressures are path dependent, but that there are upper and lower values of mean effective pressure, depending on initial soil conditions. Results are compared to those from alternative methods of measurement.
941173 Finite element code for subsidence problems: LANGAMINE Charlier, R, Radu, J P; Li, Q F lnt Assoc Engng Geol Bull N47, April 1993, P5-11 Basic difficulties in numerical analysis of subsidence are outlined and the case of Shanghai, horizontal aquifers of almost infinite extent, examined. The finite element code LANG A M I N E is proposed for use in such cases. Its capabilities are described: ability to handle large strains, seepage, a wide range of constitutive models, and availability of preprocessors and postproccssors. The coupled compaction-flow model is then illustrated.
941174 Applying the LANGAMINE model to compute land subsidence in Shanghai Dassargues, A; Schroeder, C; Li, X L Int Assoc Engng Geol Bull N47, April 1993, P13-26 An attempt to numerically simulate the subsidence of the Shanghai district due to groundwater pumping over the period 1925-2000 is presented. Preparation of the data and variation of the hydrodynamic parameters during compaction are described. The L A N G A M I N E model is introduced, spatial discretization of the layered sediments and time discretization of the period considered, and initial and boundary conditions discussed. Results are presented in a following paper.
941175 Comparison of e-log p and log e-log p methods for the determination of preconsolidation stress Krishnamohan, R Indian Geotech J 1122, N4, Oct 1992, P215-226 One dimensional consolidation tests were carried out on sediments ranging from very soft to very stiff clays with high to medium plasticity. Test data were analysed using both e-log p and log e-log p methods. Preconsolidation stresses indicated were identical in some cases, but varied by 100% in others. This can, however, be attributed to random chance occurrence of potential subjective errors. When both methods were applied to a remoulded sample whose preconsolidation stress was known, they gave the same result, within 9% of true value. It is suggested that each may be used to check the results from the other.
941176 Finite element formulation in Lagrangian co-ordinates for beat and fluid flow in compacting sedimentary basins Wangen, M lnt J Num Anal Meth Geomech V17, N6, June 1993, P401432 A numerical model is presented of heat and fluid flow in a compacting sedimentary basin. The final sediment particle positions in the completely compacted basin are described using Lagrangian coordinates. A finite element formulation for excess water pressure and temperature using the Lagrangian coordinates is presented, together with an equivalent formulation in the real coordinates, which is in effect the Lagrangian grid mapped to the real space. The model is validated against results from two dimensionless one-dimensional solutions.
Compressibility, swelling and consolidation See also." 941358
941169 Field and laboratory experience with the use of strip drains in organic soils Koda, E; Szymanski, A; Wolski, W Can Geotech J V30, N2, April 1993, P308-318 The performance of vertical strip drains to speed consolidation of peat and gyttja during stage construction of embankments has been examined. Effective increase in bearing capacity was seen, but a significant decrease in drainage capacity occurred during construction, depending on the nature of the drain filter material. This was further studied in the laboratory. The decrease did not significantly affect consolidation rate. Buckling of the drains had little effect on drainage capacity. The use of vertical drains reduced horizontal displacements below the embankment during construction.
941170 Geotechnical properties of dune sands in Kuwait AI-Sanad, H A; Ismael, N F; Nayfeh, A J Engng Geoi V34, N1/2, May 1993, P45-52 Dune sands from four sites in Kuwait have been characterised in the laboratory. Grain size distribution, strength, and compressibility were measured and compaction tests carried out. The sands are fine, poorly graded silica sands with almost no fines. Compacted sands show high strength and low compressibility and are not sensitive to saturation or wetting and so are suitable materials for embankment fill or backfill.
941171 Compression of collapsed loess: studies on bonded and unbonded soils Feda, J; Bohac, J; Herle, I Engng Geoi V34, N1/2, May 1993, P95-103 Compression of bonded (collapsible) and debonded (collapsed) Sedlec loess has been studied in the laboratory. Oedometric and triaxial compression curves yield identical compression indices. Intrinsic and semilogarithmic compression lines compare well with data on the debonded soils. Reconstituted samples will develop a bonded structure with age, as do natural samples. As reconstituted samples have a much lower initial porosity than the natural loess, these aged and bonded soils do not collapse when the bonding is destroyed by loading.
941172 Swelling pressure behavior under controlled suction. Technical note Habib, S A; Karube, D Geotech Test J V16, N2, June 1993, P271-275 One dimensional consolidation tests carried out in a modified floating ring oedometer under conditions of controlled suction with simultaneous measurement of vertical and lateral swelling pressures are described. Results show both pressures are path dependent, but that there are upper and lower values of mean effective pressure, depending on initial soil conditions. Results are compared to those from alternative methods of measurement.
941173 Finite element code for subsidence problems: LANGAMINE Charlier, R, Radu, J P; Li, Q F lnt Assoc Engng Geol Bull N47, April 1993, P5-11 Basic difficulties in numerical analysis of subsidence are outlined and the case of Shanghai, horizontal aquifers of almost infinite extent, examined. The finite element code LANG A M I N E is proposed for use in such cases. Its capabilities are described: ability to handle large strains, seepage, a wide range of constitutive models, and availability of preprocessors and postproccssors. The coupled compaction-flow model is then illustrated.
941174 Applying the LANGAMINE model to compute land subsidence in Shanghai Dassargues, A; Schroeder, C; Li, X L Int Assoc Engng Geol Bull N47, April 1993, P13-26 An attempt to numerically simulate the subsidence of the Shanghai district due to groundwater pumping over the period 1925-2000 is presented. Preparation of the data and variation of the hydrodynamic parameters during compaction are described. The L A N G A M I N E model is introduced, spatial discretization of the layered sediments and time discretization of the period considered, and initial and boundary conditions discussed. Results are presented in a following paper.
941175 Comparison of e-log p and log e-log p methods for the determination of preconsolidation stress Krishnamohan, R Indian Geotech J 1122, N4, Oct 1992, P215-226 One dimensional consolidation tests were carried out on sediments ranging from very soft to very stiff clays with high to medium plasticity. Test data were analysed using both e-log p and log e-log p methods. Preconsolidation stresses indicated were identical in some cases, but varied by 100% in others. This can, however, be attributed to random chance occurrence of potential subjective errors. When both methods were applied to a remoulded sample whose preconsolidation stress was known, they gave the same result, within 9% of true value. It is suggested that each may be used to check the results from the other.
941176 Finite element formulation in Lagrangian co-ordinates for beat and fluid flow in compacting sedimentary basins Wangen, M lnt J Num Anal Meth Geomech V17, N6, June 1993, P401432 A numerical model is presented of heat and fluid flow in a compacting sedimentary basin. The final sediment particle positions in the completely compacted basin are described using Lagrangian coordinates. A finite element formulation for excess water pressure and temperature using the Lagrangian coordinates is presented, together with an equivalent formulation in the real coordinates, which is in effect the Lagrangian grid mapped to the real space. The model is validated against results from two dimensionless one-dimensional solutions.