Loess and its engineering problems in the USSR

Loess and its engineering problems in the USSR

83A 902147 Seepage effects on sedimentation of fly ash slurry Wardell, R E; Findlay, R C; Muzzy, M M Proc Conference on Hydraulic Fill Structures, Fo...

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902147 Seepage effects on sedimentation of fly ash slurry Wardell, R E; Findlay, R C; Muzzy, M M Proc Conference on Hydraulic Fill Structures, Fort Collins, 15-18 April 1988 P389-409. Pubi New York: ASCE, 1988 (Geotechnical Special Publication No 21)

902151 Shear strength and earth pressure in expansive soils Katti, R K Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P75-I 10. Publ Beijing: International Academic Publishers. 1989

Geotechnical studies of hydraulically filled fly ash slurry were carried out. The slurry is predominantly non-plastic, silt-size particles. Geophysical survey, geological logging and sample collection were used for site characterisation. Laboratory tests were undertaken to determine sedimentation and permeability characteristics, for conditions of sedimentation followed by flow and sedimentation with flow. Results are discussed and a predictive analogue to consider seepage effects presented. Recommendations are made for work needed to develop a sedimentation model which incorporates seepage forces.

The properties of expansive soils are reviewed. Behaviour of expansive and non-expansive clayey soils is compared and explained in terms of the physical-chemical-electrical properties of the constituent minerals. Mathematical expressions are developed describing swelling pressure in terms of material parameters. Lateral pressure development under heave and passive conditions is examined. Heave consolidation is examined. Shear strength aspects of expansive soils are extensively studied. Case study illustrations of problems caused by expansive soils are presented. 91 refs.

902152 Collapsing capacity of loessial soils Andrei, S; Manea, S

902148 Properties of slurried coal tailings Williams, D J; Morris, P H

Proc Conference on Hydraulic Fill Structures, Fort Collins, 15-18 April 1988 P410-429. Publ New York: ASCE, 1988 (Geotechnical Special Publication No 21) Processes involved in disposal and rehabilitation of coal mine tailings and some important engineering properties have been studied for prediction of railings behaviour and development of alternative disposal and rehabilitation techniques. Processes described are beaching, sedimentation, consolidation, crusting and rehabilitation. Particle relative density, dry unit weight versus moisture content, permeability, coefficient of consolidation and shear strength are discussed.

Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P189-194. Publ Beijing: International Academic Publishers, 1989 Structural aspects of collapse of residual soil and factors which affect it are examined. A method to forecast deformations associated with stress or moisture changes, and a method to evaluate equilibrium moisture content at given soil conditions are presented. These may be used in conjunction with field property measurements to predict soil settlement.

902153 Some features of Romanian loessial soils Antonescu, I

902149 Rheological peculiarity of clayey soils deformation under swelling Mustafayev, A A Proc International Conference on Rheoiogy and Soil Mechanics, Coventry, 12-16 Sept 1988 P139-146. Publ London: Elsevier, 1988 Experimental data from tests on swelling soils have been analysed, showing that the deformation of such soils is a rheological process. Analysis of the derived curves shows that temporal variations of stress strain rate of swelling clay soils should be interpreted by the linear hereditary creep theory of Boltzmann-Volterr.

902150 Loess and its engineering problems in the USSR Abelev, M Y Proc International Conference on Engineering Problems of

Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P195-200. Publ Beijing: International Academic Publishers, 1989 Engineering properties of loessial deposits in Romania are described, including collapsibility. Failure mechanisms affecting structures on loess are examined. Foundation design is considered, together with soil improvement methods, including compaction with rammers or stone columns, prewetting, and chemical or thermal stabilisation. Controlled wetting or partial soil excavation are used to remedy tilted structures. Problems arising due to gradual rise in groundwater table beneath structures are finally discussed.

902154 Consolidation of collapsible soils as a way to raise bearing capacity of foundation bases collapsible soil. Foundation, pile field, compacted soil,tamped trench, soil base Bagdsarov, Y A; Arutyunov, I S; Lunyov, A G Proc International Conference on Engineering Problems of

Regional Soils, Beijing, 11-15 August 1988 P3-6. Publ Beijing: International Academic Publishers, 1989

Regional Soils, Beijing, 11-15 August 1988 P201-206. Publ BeUing: International Academic Publishers, 1989

Loess soils cover about 14% of the USSR. Many structures built in the 1920s failed due to settlement, and a comprehensive program to determine collapse properties, design preventative and remedial soil treatments, and optimise foundation design was undertaken. Soil testing methods are described. Pile or raft foundations are used. Chemical stabilisation, compaction by earth piles or mechanical means, or wetting with simultaneous loading are soil treatments practised.

A new method applicable to all construction of structures on collapsible soils of type II (potential collapse of over 20cm) is presented. An array of cast-in-place concrete piles in rampierced holes is constructed within a barrier strip of compacted soil. The presence of the perimeter barrier leads to increased pile friction and lower settlement. The use of foundations in tamped trenches, and of tamped subbases is also discussed.

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