Field observations of frost action in intact and weathered Champlain Sea clay

1995 ◽  
Vol 32 (4) ◽  
pp. 689-700 ◽  
Author(s):  
J.-M. Konrad ◽  
M. Roy ◽  
P. La Rochelle ◽  
S. Leroueil ◽  
G. Bergeron
Keyword(s):  
Key Words ◽  
Frost Heave ◽  
Field Observations ◽  
Freeze Thaw ◽  
Frost Action ◽  
Intact State ◽  
Potential Value ◽  
Field Instrumentation ◽  
Segregation Potential ◽  
Undrained Strength

This paper presents the results of a field study on frost action in sensitive Saint–Alban clay both in an intact state, never subjected to any freeze–thaw cycles, and in its weathered state, corresponding to thousands of freeze–thaw cycles. It appears that intact clay is highly frost susceptible and displays frost heave of about 20 cm for the 1989–1990 freezing season. The segregation potential of intact clay ranges between 425 and 550 × 10−5 mm2/(s∙ °C), while that of the crust is only about 40 to 50 × 10−5 mm2/(s∙ °C). In the field, destructured clay displayed a segregation potential value of 265 × 10−5 mm2/(s∙ °C). Loss of bearing capacity during thaw of frozen intact clay is substantial, with reduction in undrained strength from 10 to 2.5 kPa. Key words : sensitive clays, frost heave, field, instrumentation, segregation potential.

Subsoil investigation of ice lensing at the Calgary, Canada, frost heave test facility

1988 ◽  
Vol 25 (2) ◽  
pp. 307-319 ◽  
Author(s):  
L. E. Carlson ◽  
J. F. (Derick) Nixon
Keyword(s):  
Key Words ◽  
Potential Model ◽  
Frost Heave ◽  
Test Facility ◽  
Field Observations ◽  
Silty Soil ◽  
Temperature Environment ◽  
Segregation Potential ◽  
Control Section

Several frost heave mitigation modes were studied at the Calgary, Canada, chilled pipeline frost heave test facility. These included deeper burial (to increase the pressure on the frost front below the pipe) and replacement of the silty soil around the pipe with gravel for a noninsulated pipe. Frost heave at the deep-burial section and at the gravel section was less than the heave at a control section. Other pipe sections tested the effects of insulation of the pipe on the long-term frost heave, as well as the effects of replacing the silt around an insulated pipe with gravel. Summer thawing of the frost bulb around the insulated pipe results in seasonal thaw settlement of the pipe, thus reducing the long-term pipe heave, at least for the warmer ground temperature environment at the Calgary facility.Thermal simulations of the frost bulb growth and predictions of frost heave using the segregation potential model agree well with the observations.Recent excavation of two frost bulbs in silty soil led to field observations of the interior of the frost bulbs, and subsequent laboratory analysis of frost bulb samples. Ice distribution was logged and photographed following excavation of each frost bulb. Key words: frost heave, pipeline, silt, mitigation, instrumentation, field observations.

Effect of fines content on frost heave

1996 ◽  
Vol 33 (4) ◽  
pp. 678-680 ◽  
Author(s):  
Robert E Tester ◽  
Paul N Gaskin
Keyword(s):  
Key Words ◽  
Frost Heave ◽  
Cold Regions ◽  
Fines Content ◽  
Frost Action ◽  
Road Base ◽  
Pavement Structures ◽  
Freezing Test ◽  
Crushed Limestone ◽  
The U.S

In regions of seasonal frost the integrity of pavement structures is dependent on the resistance of base and subbase soils to frost action. This note describes the results of performing the U.S. Army Cold Regions Research and Engineering Laboratory CRREL II laboratory freezing test on a crushed limestone with a varying fines content. Frost heave increased linearly as fines content increased. Under the CRREL frost susceptibility criterion, the crushed gravel was satisfactory with up to 8% fines. A greater fines content resulted in an unsatisfactory classification. Key words: frost susceptibility, fines content, road base.

Effect of freeze–thaw cycles on the freezing characteristics of a clayey silt at various overconsolidation ratios

1989 ◽  
Vol 26 (2) ◽  
pp. 217-226 ◽  
Author(s):  
J.-M. Konrad
Keyword(s):  
Void Ratio ◽  
Frost Heave ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Maximum Reduction ◽  
Clayey Silt ◽  
Wide Range ◽  
Repeated Freezing ◽  
Segregation Potential ◽  
Overconsolidated Soils

Repeated freezing and thawing affect the structure of clayey silts over a wide range of consolidation ratios. While the overall void ratio of the thawed soil either decreased, as in lightly overconsolidated soils, or increased, as in heavily overconsolidated samples, freezing and thawing caused a reduction in segregation potential after each freeze–thaw event. All the changes occurred during the first three cycles. The maximum reduction in segregation potential was about 50% in all samples. The implications for frost heave predictions in the field are discussed. Key words: freeze–thaw, clayey silt, segregation potential, frost heave.

Stress Analysis of Pipeline Subjected to Differential Frost Heave

2013 ◽  
Author(s):  
Yan Di ◽  
Jian Shuai ◽  
Lingzhen Kong ◽  
Xiayi Zhou
Keyword(s):  
Strain Analysis ◽  
Element Model ◽  
Frozen Soil ◽  
Computational Method ◽  
Frost Heave ◽  
Safe Operation ◽  
Stress Strain ◽  
Segregation Potential ◽  
Differential Frost Heave ◽  
Design Construction

Frost heave must be considered in cases where pipelines are laid in permafrost in order to protect the pipelines from overstress and to maintain the safe operation. In this paper, a finite element model for stress/strain analysis in a pipeline subjected to differential frost heave was presented, in which the amount of frost heave is calculated using a segregation potential model and considering creep effects of the frozen soil. In addition, a computational method for the temperature field around a pipeline was proposed so that the frozen depth and temperature variation gradient could be obtained. Using the procedure proposed in this paper, stress/strain can be calculated according to the temperature on the surface of soil and in a pipeline. The result shows the characteristics of deformation and loading of a pipeline subjected to differential frost heave. In general, the methods and results in this paper can provide a reference for the design, construction and operation of pipelines in permafrost areas.

Storage Life of Refrozen Silver Hake (Merluccius bilinearis) Processed as Fillets am Minced Flesh from Thawed, Stored, Round-Frozen Fish

1977 ◽  
Vol 34 (12) ◽  
pp. 2369-2373 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
D. H. North ◽  
Barbara Smith Lall ◽  
R. A. Keith
Keyword(s):  
Key Words ◽  
Frozen Storage ◽  
Storage Life ◽  
Freeze Thaw ◽  
Acceptable Quality ◽  
Frozen Fish ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
Protein Extractability

Refrozen silver hake (Merluccius bilinearis), processed as fillets and minced flesh after thawing of stored round fish that had been frozen within 14 h of capture, underwent rapid deterioration during storage at −18 °C compared with once-frozen control materials from the same lot of fish. The estimated maximum storage life of silver hake refrozen as fillets after 3 and 6 mo storage of the round fish at −25 °C was reduced to about 4.5 and 1 mo, respectively, from 10 mo for once-frozen control fillets. Quality of the refrozen materials immediately after thawing and refreezing was similar to that of the round-frozen fish, except after 6 mo, where some initial deterioration occurred, particularly in minced flesh. Minced flesh was more unstable in frozen storage than fillets. In all once- and twice-frozen materials, formation of dimethylamine occurred concomitantly with decrease in protein extractability. Round-frozen fish underwent no loss in protein extractability during 6 mo storage at −25 °C, but some lipid hydrolysis occurred. These results suggest that the freeze–thaw–refreeze process as applied to silver hake will yield a final product of acceptable quality provided that storage of the round fish does not exceed 3–4 mo and that the refrozen materials are marketed within a month after processing. Key words: silver hake, Merluccius bilinearis, refrozen storage, dimethylamine, minced flesh

scholarly journals Volume change behaviour and microstructure of stabilized loess under cyclic freeze–thaw conditions

2016 ◽  
Vol 43 (10) ◽  
pp. 865-874 ◽  
Author(s):  
Sheng-lin Wang ◽  
Qing-feng Lv ◽  
Hassan Baaj ◽  
Xiao-yuan Li ◽  
Yan-xu Zhao
Keyword(s):  
Fly Ash ◽  
Volume Change ◽  
Cement Content ◽  
Frost Heave ◽  
Equivalent Diameter ◽  
Surface Porosity ◽  
Change Rate ◽  
Freeze Thaw ◽  
Significant Damage ◽  
The Impact

Freeze–thaw action is considered to be one of the most destructive actions that can induce significant damage in stabilized subgrades in seasonally frozen loess areas. Laboratory tests including frost heave – thaw shrinkage and microstructure change during freeze–thaw cycles were conducted to evaluate the volume change rate of loess stabilized with cement, lime, and fly ash under the impact of cyclic freeze–thaw conditions. The loess specimens collapsed after eight freeze–thaw cycles (192 h), but most stabilized loess specimens had no visible damage after all freeze–thaw cycles were completed. All of the stabilized loess samples underwent a much smaller volume change than the loess alone after the freeze–thaw cycles. Although surface porosity and equivalent diameter of stabilized loess samples increased, the stabilized loess can retain its microstructure during freeze–thaw cycles when the cement content was less than 6%. To ensure freeze–thaw resistance of stabilized loess subgrades, the mix proportions of the three additives was recommended to be 4 to 5% cement, 6% lime, and 10% fly ash.

Determination of the consistency limits of soils by the fall cone test

1986 ◽  
Vol 23 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Y. Wasti ◽  
M. H. Bezirci
Keyword(s):  
Shear Strength ◽  
Key Words ◽  
Water Content ◽  
Strength Criterion ◽  
Undrained Shear Strength ◽  
Wide Range ◽  
Undrained Strength ◽  
Content Range ◽  
Undrained Shear

The liquid and plastic limits for a variety of natural and artificial soils covering a wide range of plasticity, as determined by the Casagrande method and the fall cone test and based on a strength criterion, were compared. To check the validity of the strength criterion, the undrained shear strength of these soils has been determined with a laboratory vane over the water content range between these limits. A limited comparison of the undrained strength values obtained from the vane test and fall cone test is also given. Key words: Atterberg limits, consistency, fall cone, laboratory vane, shear strength.

Frost heave characteristics of undisturbed sensitive Champlain Sea clay

1994 ◽  
Vol 31 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J.-M. Konrad ◽  
J.T.C. Seto
Keyword(s):  
Pore Pressure ◽  
Laboratory Tests ◽  
External Source ◽  
Frost Heave ◽  
Water Fluxes ◽  
Excess Water ◽  
Segregation Potential ◽  
Structured Clay ◽  
Compressible Soil ◽  
Surface Heave

Undisturbed Champlain Sea clay samples were subjected to laboratory freezing tests with pore-pressure measurements in order to determine the freezing characteristics of a structured compressible soil. Step-freezing and ramped-freezing tests with applied back pressure were conducted on 10 cm high samples in open-system conditions. Significant pore-pressure reductions in the unfrozen soil induce important frost-induced consolidation and destructuration of the clay. It was found that the freezing characteristics of Saint-Alban clay are best defined by the segregation potential at the active ice lens, SPℓ, which includes water fluxes generated within the frozen fringe and within the unfrozen soil as excess water is expelled during consolidation, and finally water from an external source. For the Saint-Alban clay, SPℓ values of the intact clay ranged between 450 and 600 × 10−5 mm2/(s °C), whereas those of destructured clay at a lower void ratio were significantly smaller. Back-calculating the segregation potential solely from surface heave measurements in laboratory tests may underestimate considerably the frost susceptibility of compressible structured clays. Segregation potential inferred from instrumented field sites was 430 × 10−5 mm2/(s °C) and is consistent with the laboratory tests results. Key words : freezing, frost heave, structured clay, undisturbed, consolidation.

Sign in / Sign up

Export Citation Format

Share Document