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Some geological and engineering characteristics of lodgement tills from the Vale of St Albans, Hertfordshire
221A 885148 Overconsolidation ratio of clays from penetration pore pressures, Technical note Sully, J P; Campanella, R G; Robcrtson, P K J Geotech Engng Div ASCE VII4, N2, Feb 1988, P209-216 Although attempts have been made to correlate various pore pressure parameters with stress history for clay deposits, no universal formula has been found. It is likely, however, that a pore pressure-OCR relation can be established for a specific deposit. The normalised distributions of dynamic pore pressures measured at two positions on the cone have been evaluated. The difference between these values appears to provide a good indication of OCR for clays. 885149 Application of a simple soil-water hysteresis model Hogarth, W L; Hopmans, J; Parlange, J Y; Haverkamp, R J Hydrol 1/98, NI/2. 15 March 1988, P21-29 A simple hysteresis model is reformulated on the basis of the Brooks and Corey equation for the relationship between soilwater content and matric potential. In principle, the method requires the knowledge of a drying curve (boundary or primary) to predict the wetting boundary and all scanning curves. Experimental observations used recently to assess a variety of soil-water hysteresis models show that the present model is simple, accurate, and general. Auth. 885150 Constitutive model for consolidation of granular materials Wang, P T Powder Technol V54, N2, Feb 1988, P107-118 A version of endochronic theory is presented and used to describe the mechanical behaviour of granular materials including cohesionless sands and metal powders. Volumetric and deviatoric deformation and shearing induced densification under monotonic and cyclic loading are investigated. Results from densification of air dried Toyoura sand in the ring type torsion test with cyclic loading are used to illustrate the applicability of the theory. 885151 Some geological and engineering characteristics of lodgement tills from the Vale of St AIbans, Hertfordshire Little, J A; Atkinson, J H Q J Engng Geol V21, N2, 1988. P183-199 One dimensional consolidation tests were undertaken on lodgement tills, to determine compression, swelling and permeability characteristics of undisturbed and reconstituted samples. The ocdometer tests indicated the soils in situ are not significantly anisotropic. A variation in compression and swelling between disturbed and undisturbed samples may be explained by the crystalline calcite cement, whilst swelling and recompression indices indicate a substantial threshold effect when the direction of loading is changed. 885152 Foundation heave on a lime and cement treated soil containing gypsum (In French) Habib, P; Aversenc, D Rev Fr Geotech N42, 1988, P61-64 Heave of a foundation slab laid on compacted fill material treated with lime and cement is described. Chemical analysis of the fill material detected the presence of gypsum, and the heave was taken to be caused by the gypsum swelling. Remedial structural measures are illustrated.
885153 Design of drains and surcharge in reclmations Tan, S A; Lee, S L; Karunaratne, G P; Choa, V Soils Found V27, N4, Dec 1987, P89-98 Blot consolidation theory, using a 2-d plane strain finite element analysis, is used to study the effect of vertical drains and surcharge width on the rate of surface settlement of thick marine clays used in reclamation. To simulate the effect of vertical drains, the soil with drains was approximated to a soil with an equivalent increased vertical permeability. The numerical model is then used to simulate the back pressure effect, caused by inflow and back up of excess of pore pressure from the undrained zone, on the drained zone. Predicted values correlate well with those measured at the Changi Airport soil improvement works.
885154 Prediction and performance of structures on expansive soils Fredlund, D G Proc International Symposium on Prediction and Performance in Geoteclmical Engineering, Calgary, 17-19 June 1987 P5160. Publ Rotterdam: A A Balkema, 1987 The numerous analytical procedures proposed for prediction of heave in swelling soils are examined within the context of unsaturated soil theory. The aims are to explain how past, present and future behaviour of a swelling soil can be explained in terms of stress state variables, to outline a prediction method based on one-dimensional oedometer tests, and to explain how data should be interpreted. Two case histories are presented.
885155 Fact and fiction in the field of vertical drainage Hansbo, S Proc International Symposium on Prediction and Performance in Geotechnical Engineering, Calgary, 17-19 June 1987 P6172. Publ Rotterdam: A A Balkema, 1987 The governing theoretical equations controlling primary consolidation are presented, and the important soil and drain parameters relevant to vertical drainage discussed. The reliability of design methods is examined using data from longterm tests on clay subsoils. It is seen that vertical drainage can successfully speed up consolidation and that rates may be predicted with reasonable accuracy. The use of vertical drains in peat is also discussed with reference to field tests.
885156 Mechanical interaction between rock and multiple-component shaft or borehole plugs Fuenkajorn, K; Daemen, J J K Proc 28th US Symposium on Rock Mechanics, Tucson, 29 June-I July 1987 P165-172. Publ Rotterdam: A A Balkema, 1987 Pipe swelling tests were performed to determine the swelling pressures of bentonite and cement plugs. Finite elements were used to analyse the mechanical interaction between the plug and the rock, assuming the materials are linearly elastic, and indicated that the damaged zone around openings can increase radial displacement in the rock adjacent to the cement plug. This may be reduced by designing multiple component plugs.
© 1988 Pergamon Press pie. Reproduction not permitted
885153 Design of drains and surcharge in reclmations Tan, S A; Lee, S L; Karunaratne, G P; Choa, V Soils Found V27, N4, Dec 1987, P89-98 Blot consolidation theory, using a 2-d plane strain finite element analysis, is used to study the effect of vertical drains and surcharge width on the rate of surface settlement of thick marine clays used in reclamation. To simulate the effect of vertical drains, the soil with drains was approximated to a soil with an equivalent increased vertical permeability. The numerical model is then used to simulate the back pressure effect, caused by inflow and back up of excess of pore pressure from the undrained zone, on the drained zone. Predicted values correlate well with those measured at the Changi Airport soil improvement works.
885154 Prediction and performance of structures on expansive soils Fredlund, D G Proc International Symposium on Prediction and Performance in Geoteclmical Engineering, Calgary, 17-19 June 1987 P5160. Publ Rotterdam: A A Balkema, 1987 The numerous analytical procedures proposed for prediction of heave in swelling soils are examined within the context of unsaturated soil theory. The aims are to explain how past, present and future behaviour of a swelling soil can be explained in terms of stress state variables, to outline a prediction method based on one-dimensional oedometer tests, and to explain how data should be interpreted. Two case histories are presented.
885155 Fact and fiction in the field of vertical drainage Hansbo, S Proc International Symposium on Prediction and Performance in Geotechnical Engineering, Calgary, 17-19 June 1987 P6172. Publ Rotterdam: A A Balkema, 1987 The governing theoretical equations controlling primary consolidation are presented, and the important soil and drain parameters relevant to vertical drainage discussed. The reliability of design methods is examined using data from longterm tests on clay subsoils. It is seen that vertical drainage can successfully speed up consolidation and that rates may be predicted with reasonable accuracy. The use of vertical drains in peat is also discussed with reference to field tests.
885156 Mechanical interaction between rock and multiple-component shaft or borehole plugs Fuenkajorn, K; Daemen, J J K Proc 28th US Symposium on Rock Mechanics, Tucson, 29 June-I July 1987 P165-172. Publ Rotterdam: A A Balkema, 1987 Pipe swelling tests were performed to determine the swelling pressures of bentonite and cement plugs. Finite elements were used to analyse the mechanical interaction between the plug and the rock, assuming the materials are linearly elastic, and indicated that the damaged zone around openings can increase radial displacement in the rock adjacent to the cement plug. This may be reduced by designing multiple component plugs.
© 1988 Pergamon Press pie. Reproduction not permitted