Quick clays of eastern Canada

Crawford, Carl B.

doi:10.1016/0013-7952(68)90002-1

“…Leda clay is a postglacial marine clay found extensively as a surficial deposit along the St. Lawrence and Ottawa Rivers and their tributaries (Crawford 1968). The sample of Leda clay was from an undisturbed soil core taken with a 12.7-cm diameter Osterberg sampler at a depth of 20 to 25 ft (6.1 to 7.6 m) on the site of the National ~eseaich Council ;ear the eastern city limits of Ottawa.…”

Section: Soils and Soil Sample Preparation For Icementioning

confidence: 99%

Thermal conductivity of frozen soils

Penner¹

1970

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/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. Sciences, 7, 3, pp. 982-987, 1970-05-01 Thermal conductivity of frozen soils Penner, E. Thermal conductivity measurements of two frozen soils, Leda clay and Sudbury silty clay, taken at temperatures between 0 and -22 "C by means of a thermal probe and a transient heat flow technique, compare favorably with estimates of thermal conductivity calculated by the DeVries method. Both measured and estimated values show a similar trend of increasing thermal conductivity as the temperature is lowered and the ice content grows. This increase is associated with the higher thermal conductivity of ice compared with that of water. Canadian Journal of EarthThe thermal conductivity of soil is known to be strongly dependent on density, mineral type, grain size, and moisture content (Kersten 1949), but relatively insensitive to temperature changes above 0 "C. Below 0 "C, where soils have a temperature-dependent ice content, a constant thermal conductivity cannot be assumed in heat flow calculations because the thermal conductivity of ice is more than four times greater than that of water.It is known that all the water in soil and other porous systems does not freeze at the same temperature; that the ice content gradually increases as the temperature is lowered (Love11 1957, Penner 1963a, Williams 1964. The relation between temperature below freezing and the amount of ice and water is peculiar to each soil in much the same way as is the pF1-moisture content relation. The main factors thought to control the amount of water in frozen soils are specific surface area, mineral type, kind of exchangeable ions, soluble salt content of the pore water, and pore size distribution. In general and for an originally saturated system, fine textured soils contain more unfrozen water at a given temperature below freezing than do coarse textured soils.In the present paper thermal conductivity was determined by a transient heat flow method using a line heat source developed (according to Woodside 1958) by Stalhane and Pyk (1931). This method has been used by Woodside and Cliffe (1959) and by Penner (1962) for unfrozen soils, but no previous attempt has been made to apply the method to frozen soils. For comparison with measured values the thermal conductivity of two soils is estimated using the DeVries (1952DeVries ( , 1963 approach. Methods and Materials Thermal Conductivity MeasurementsA transient heat flow method using a line heat source was employed to measu...

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“…Transpiration from trees has been held responsible for vertical ground movements (Bozozu~ and BURN, 1960). Apart from shrinkage problems, compressibility characteristics are often hard to evaluate, and there has been disagreement in the settlements predicted by computation and those found by field observation of actual structures (CRAWFORD, 1968).…”

Section: Geotechnical Backgroundmentioning

confidence: 99%

Fabric of Leda clay investigated by optical, electron-optical, and X-ray diffraction methods

Gillott

¹

1970

Engineering Geology

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/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur.Engineering Geology, 4, 2, pp. 133-153, 1970-07-01 Fabric of leda clay investigated by optical, electron-optical, and x-ray diffraction methods Gillott, J. E. Fabric, palaeosalinity and engineering data are given for five samples of Leda clay. It is shown that the layer structure silicates in two of the samples are oriented parallel to the bedding; that in the other three samples the platy minerals have a near random arrangement. X-ray diffraction studies showed that there was no difference in the orientation of 7A and 10A layer structure silicates.Palaeosalinity values deduced from boron content indicate that three of the samples were deposited in water that was fresher than normal marine. The other two samples were deposited in a nearly normal marine environment. The correlation between fabric and palaeosalinity data is fairly good, though information on a larger number of samples is needed before the method can be satisfactorily evaluated for Leda clay.Moisture removal by four different methods shows that original fabric can be affected by the technique of sample preparation.The evidence is in agreement with the idea that fabric was Inore affected by conditions at the time of deposition than by subsequent events.

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“…Their conclusion is that the fabric supports the cardhouse model and that it was produced by deposition in the flocculated state. Electron micrographs by Gillott (1969) and Crawford (1968) also show a general random orientation of clay particles in a similar clay. Crawford (1968) states that the Leda clays, like other sensitive clays, are thought to have a cardhouse fabric because of their environment of deposition.…”

Section: Introductionmentioning

confidence: 81%

“…Gadd (1962) however, suggests that there may have been redeposition of marine clays into fresh water. Crawford (1968) states that "if these clays were actually deposited in fresh water, some explanation must be found for their open structure and sensitivity". It is the purpose of this paper to present evidence that the open structure may be produced also by flocculation in fresh water.…”

Section: Introductionmentioning

confidence: 99%