New ice lens initiation condition for frost heave in fine-grained soils

2012 ◽  
Vol 82 ◽  
pp. 8-13 ◽  
Author(s):  
Tezera F. Azmatch ◽  
David C. Sego ◽  
Lukas U. Arenson ◽  
Kevin W. Biggar
Keyword(s):  
Frost Heave ◽  
Fine Grained ◽  
Initiation Condition

Field frost heave predictions using the segregation potential concept

1982 ◽  
Vol 19 (4) ◽  
pp. 526-529 ◽  
Author(s):  
John F. Nixon
Keyword(s):  
Field Conditions ◽  
Frost Heave ◽  
Test Facility ◽  
Potential Approach ◽  
Fine Grained ◽  
Practical Engineering ◽  
Segregation Potential ◽  
Pipe Lines

The Konrad–Morgenstern theory of frost heave using the segregation potential concept is briefly outlined, and the method of predicting frost heave under field conditions is reviewed. A recent paper by Nixon et al. describes the operation and results from two circular frost heave test plates installed at the Foothills Pipe Lines test facility in Calgary. The frost heave theory using the segregation potential approach has been applied in its simplest form to predict the frost heave beneath these test plates and the agreement is found to be very good. Current geothermal modelling, coupled with the Konrad–Morgenstern theory of frost heave, appears to be capable of reasonable predictions of frost heave in fine-grained soils under practical engineering conditions.

Estimation of the segregation potential of fine-grained soils using the frost heave response of two reference soils

2005 ◽  
Vol 42 (1) ◽  
pp. 38-50 ◽  
Author(s):  
Jean-Marie Konrad
Keyword(s):  
Empirical Relationship ◽  
Clay Mineralogy ◽  
Frost Heave ◽  
Free Access ◽  
Overburden Pressure ◽  
New Approach ◽  
Fine Grained ◽  
Average Grain Size ◽  
Fine Grained Soil ◽  
Segregation Potential

The frost heave response of quarry fines from several locations in the Province of Quebec was studied in the laboratory using one-dimensional step-freezing tests with free access to water. Comparison of the segregation potential values obtained from these tests with available data on fine-grained soils revealed the importance of including clay mineralogy and overburden effects in any predictive empirical relationship, especially when fines are nonclays. A new approach is presented to estimate segregation potential values using the frost heave response of two reference soils. The reference characteristics consist of a relationship between segregation potential at zero overburden pressure, specific surface area, and average grain size of the fines fraction for two artificial soil mixtures in which the clay mineral is poorly crystallized kaolinite. The prediction of segregation potential values using the reference frost heave characteristics approach is more robust and reliable than other empirical approaches that do not specifically distinguish between clay and nonclay fines. Furthermore, the new approach was also efficient for the assessment of frost susceptibility of well-graded glacial tills.Key words: fine grained, soil, mineralogy, laboratory, fines, clay, nonclay.

Field Test Study on Frost-Heave of Subgrade in Seasonal Frozen Region along Haerbin-Dalian Passenger Dedicate Line

2013 ◽  
Vol 671-674 ◽  
pp. 45-49 ◽  
Author(s):  
Jin Fang Hou ◽  
Yong Li Wang ◽  
Jun Feng
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Field Test ◽  
Frost Heave ◽  
Soil Pressure ◽  
Construction Technique ◽  
Effective Measure ◽  
Fine Grained ◽  
Environment Temperature ◽  
Fine Grained Soil

The new constructing railway Haerbin-Dalian Dedicate Line runs through the typical seasonal frozen region. For the purpose of estimating the quality of subgrade construction, a field test was played. Placed the monitoring instrument and measure the soil temperature, settlement and soil pressure etc.. The monitoring data shows that the change of soil temperature is less than the environment temperature. The maximum frost depth is 1.66m. In this depth, the fine-grained soil with high frost-heave characteristic should not be as the subgrade. The effective measure to prevent the rain percolated through the subgrade is important. And the filling of subgrade should be constructed strictly according to the maximal degree of compaction and keep the best water content. The settlement of subgrade is less than 15mm, the water content is also less than the prime frost-heave water content and the frost-heave force is very small. Thus, the construction technique subgrade is feasible.

Improvements in Frost Heave Laboratory Testing of Fine-Grained Soils

2008 ◽  
Vol 22 (3) ◽  
pp. 65-78 ◽  
Author(s):  
Margaret M. Darrow ◽  
Scott L. Huang ◽  
Yuri Shur ◽  
Satoshi Akagawa
Keyword(s):  
Laboratory Testing ◽  
Frost Heave ◽  
Fine Grained

Prediction of frost heave in the laboratory during transient freezing

1982 ◽  
Vol 19 (3) ◽  
pp. 250-259 ◽  
Author(s):  
J.-M. Konrad ◽  
N. R. Morgenstern
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Temperature Gradient ◽  
Water Intake ◽  
Applied Load ◽  
Frost Heave ◽  
Freezing Soil ◽  
Fine Grained ◽  
Segregation Potential ◽  
Rate Of Cooling

Previous studies have demonstrated that, close to steady-state conditions, the ratio of the water intake velocity to the temperature gradient across the frozen fringe, called the segregation potential, is an important property characterizing a freezing soil. Under the more general conditions of transient freezing it is shown that the freezing characteristics of a given soil under zero applied load are defined by the segregation potential, the suction at the frozen–unfrozen interface, and the rate of cooling of the frozen fringe. These parameters form a relationship called the characteristic frost heave surface that can be used to predict mass transfer during the freezing of fine-grained soils. Examples of freezing tests conducted under various conditions are reproduced numerically to illustrate the fundamental character of this surface.

Application of an image management system in microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1052-1053
Author(s):  
Richard S. Chemock
Keyword(s):  
Data Storage ◽  
Cost Savings ◽  
Image Data ◽  
Analytical Techniques ◽  
Operational Mode ◽  
Fine Grained ◽  
Image Recording ◽  
Primary Output ◽  
Capacity Data ◽  
Image Management System

One of the most common tasks in a typical analysis lab is the recording of images. Many analytical techniques (TEM, SEM, and metallography for example) produce images as their primary output. Until recently, the most common method of recording images was by using film. Current PS/2R systems offer very large capacity data storage devices and high resolution displays, making it practical to work with analytical images on PS/2s, thereby sidestepping the traditional film and darkroom steps. This change in operational mode offers many benefits: cost savings, throughput, archiving and searching capabilities as well as direct incorporation of the image data into reports.The conventional way to record images involves film, either sheet film (with its associated wet chemistry) for TEM or PolaroidR film for SEM and light microscopy. Although film is inconvenient, it does have the highest quality of all available image recording techniques. The fine grained film used for TEM has a resolution that would exceed a 4096x4096x16 bit digital image.

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

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