scholarly journals Semiempirical Correlation between P-Wave Velocity and Thermal Conductivity of Frozen Silty Clay Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yadong Ji ◽  
Kaipeng Zhu ◽  
Chao Lyu ◽  
Shidong Wang ◽  
Dianyan Ning ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Wave Velocity ◽  
Clay Soil ◽  
P Wave ◽  
Unfrozen Water ◽  
Silty Clay ◽  
Geothermal Systems ◽  
Unfrozen Water Content ◽  
P Wave Velocity ◽  
Silty Clay Soil

In this study, the thermal conductivity and P-wave velocity of silty clay soil with different water contents are investigated through experiments at different temperatures, and a theoretical correlation between thermal conductivity and wave velocity is established. With temperature decline, the unfrozen water content is reduced and frost heave cracks propagate in soil samples. The variations in thermal conductivity and P-wave velocity are summarized as four phases. The freezing temperature of silty clay soil is between −2°C and −4°C. There is an inversely proportional relationship between thermal conductivity and P-wave velocity for silty clay soil at temperatures below freezing. The experimental results show that the theoretical correlation can well explain the relationship between P-wave velocity and thermal conductivity. These findings provide a possibility for determining the thermal conductivity easily and quickly in geothermal systems and underground engineering projects.

Contaminant migration in engineered clay barriers due to heat and moisture redistribution under freezing conditions

1995 ◽  
Vol 32 (1) ◽  
pp. 40-59 ◽  
Author(s):  
Abdel M.O. Mohamed ◽  
Raymond N. Yong ◽  
Miroslawa T. Mazus
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Fluid Intake ◽  
Clay Soil ◽  
Soil Column ◽  
Silty Clay ◽  
Freezing Time ◽  
Contaminant Migration ◽  
Unfrozen Water Content ◽  
Silty Clay Soil

In this study, the effect of temperature distribution and its influence on contaminant migration in a silty clay soil were examined. Three series of freezing-column tests were performed with three different fluids: distilled water, municipal waste leachate, and heavy metal – leachate solution. It was found that temperature distribution as a function of space and time was similar in all tests, most likely as a result of the limited amount of fluid intake. Moisture redistributions were varied as a function of experiment duration and the type of fluid used. The amount of fluid intake was directly related to the freezing time and the temperature gradient in the freezing column. The amount of unfrozen water content, ion concentration and temperature gradient were the controlling parameters that contributed to the contaminant transport in the frozen illitic silty clay soil. Na+-concentration profiles were mostly dependent on water movement in the soil column. The behaviour of Ca2+ and Mg2+ cations was similar to Na+; their concentrations in the soil solution decreased with freezing time due to ion exchange. The large accumulations of Pb2+, Zn2+, Cu2+, and Cd2+ in the lower 10 mm of the soil column occurred as a result of cation exchange and precipitation mechanisms. Key words : unsaturated, osmotic, diffusion, buffer, exchange, transport.

scholarly journals A new compositionally based thermal conductivity model for plutonic rocks

2019 ◽  
Vol 219 (2) ◽  
pp. 1377-1394 ◽  
Author(s):  
S Jennings ◽  
D Hasterok ◽  
J Payne
Keyword(s):  
Thermal Conductivity ◽  
Wave Velocity ◽  
Geometric Model ◽  
Limited Range ◽  
P Wave ◽  
Similar Degree ◽  
Primary Control ◽  
Element Geochemistry ◽  
P Wave Velocity ◽  
Wide Range

SUMMARY Thermal conductivity is a physical parameter crucial to accurately estimating temperature and modelling thermally related processes within the lithosphere. Direct measurements are often impractical due to the high cost of comprehensive sampling or inaccessibility and thereby require indirect estimates. In this study, we report 340 new thermal conductivity measurements on igneous rocks spanning a wide range of compositions using an optical thermal conductivity scanning device. These are supplemented by a further 122 measurements from the literature. Using major element geochemistry and modal mineralogy, we produce broadly applicable empirical relationships between composition and thermal conductivity. Predictive models for thermal conductivity are developed using (in order of decreasing accuracy) major oxide composition, CIPW normative mineralogy and estimated modal mineralogy. Four common mixing relationships (arithmetic, geometric, square-root and harmonic) are tested and, while results are similar, the geometric model consistently produces the best fit. For our preferred model, $k_{\text{eff}} = \exp ( 1.72 \, C_{\text{SiO}_2} + 1.018 \, C_{\text{MgO}} - 3.652 \, C_{\text{Na}_2\text{O}} - 1.791 \, C_{\text{K}_2\text{O}})$, we find that SiO2 is the primary control on thermal conductivity with an RMS of 0.28 W m−1 K−1or ∼10 per cent. Estimates from normative mineralogy work to a similar degree but require a greater number of parameters, while forward and inverse modelling using estimated modal mineralogy produces less than satisfactory results owing to a number of complications. Using our model, we relate thermal conductivity to both P-wave velocity and density, revealing systematic trends across the compositional range. We determine that thermal conductivity can be calculated from P-wave velocity in the range 6–8 km s−1 to within 0.31 W m−1 K−1 using $k({V_p}) = 0.5822 \, V_p^2 - 8.263 \, V_p + 31.62$. This empirical model can be used to estimate thermal conductivity within the crust where direct sampling is impractical or simply not possible (e.g. at great depths). Our model represents an improved method for estimating lithospheric conductivity than present formulas which exist only for a limited range of compositions or are limited by infrequently measured parameters.

Study cases of thermal conductivity prediction from P-wave velocity and porosity

Geothermics ◽  
2015 ◽  
Vol 53 ◽  
pp. 255-269 ◽  
Author(s):  
Lionel Esteban ◽  
Lucas Pimienta ◽  
Joel Sarout ◽  
Claudio Delle Piane ◽  
Sebastien Haffen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Wave Velocity ◽  
P Wave ◽  
P Wave Velocity

scholarly journals Joint Acoustic and Electrical Measurements for Unfrozen Water Saturation of Frozen Saline Soil

2020 ◽  
Author(s):  
Chuangxin Lyu ◽  
Thomas Ingeman-Nielsen ◽  
Seyed Ali Ghoreishian Amiri ◽  
Gudmund Reidar Eiksund ◽  
Gustav Grimstad
Keyword(s):  
Electrical Resistivity ◽  
Water Content ◽  
Electrical Resistance ◽  
Water Saturation ◽  
Acoustic Velocity ◽  
P Wave ◽  
Unfrozen Water ◽  
Unfrozen Water Content ◽  
P Wave Velocity ◽  
Hydrate Bearing Sediments

<p><strong>Abstract. </strong>The climate change has aroused great concern on the stability and durability of the infrastructure installed on permafrost, especially for frozen saline clay with a large amount of unfrozen water content at subzero temperature. The joint electrical resistivity and acoustic velocity measurements are conducted for frozen saline sand and onsøy clay with 50% clay content and 20~40 g/L salinity in order to determine the unfrozen water content. A systematic program of tests involves the saline sand with different salinity, natural onsøy clay with the variable of temperature and freezing-thawing cycles and reconstituted onsøy clay with distinctive density and salinity. The data analysis of measurement results in combination with previous joint measurements for frozen soil resolves the effect of temperature, salinity, soil type and freezing-thawing cycles on the acoustic and electrical properties. An increase of temperature, fine content and salinity results in a decrease of both acoustic velocity and electrical resistivity. Electrical resistivity is sensitive to salinity, while acoustic velocity changes substantially near thawing temperature. We also find that both natural and reconstituted clay with similar water content and salinity show quite different acoustic velocity and electrical resistivity, which indicates that ice crystal structures are distinctive between natural and reconstituted samples. Besides, P-wave velocity is much more sensitive to the fabric change or induced cracks than electrical resistance during freezing-thawing cycles.  In the end, acoustic models like the weighted equation (Lee et al., 1996), Zimmerman and King’s model (King et al., 1988) and BGTL (Lee, 2002) are applied to the UWS estimates based on P-wave velocity and electrical models like Archine’s law are adopted based on electrical resistance. Both estimated UWS from different methods is not always consistent. The difference can be up to 20%.</p><p><strong>Keywords:</strong> Frozen Saline Clay, Acoustic Velocity, Electrical Resistance, Unfrozen Water Saturation</p><p>References:</p><p>King, M. S., Zimmerman, R. W., & Corwin, R. F. (1988, May). Seismic and Electrical-Properties of Unconsolidated Permafrost. Geophysical Prospecting, 36(4), 349-364. https://doi.org/10.1111/j.1365-2478.1988.tb02168.x</p><p>Lee, J. S. (2002). Biot–Gassmann theory for velocities of gas hydrate-bearing sediments.</p><p>Lee, M. W., Hutchinson, D. R., Collett, T. S., & Dillon, W. P. (1996). Seismic velocities for hydrate-bearing sediments using weighted equation. Journal of Geophysical Research: Solid Earth, 101(B9), 20347-20358. https://doi.org/10.1029/96jb01886</p><p> </p>

Semiempirical correlation between thermal conductivity and electrical resistivity for silt and silty clay soils

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. MR99-MR105 ◽  
Author(s):  
Qiang Sun ◽  
Chao Lü
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Water Content ◽  
Clay Soil ◽  
Clay Soils ◽  
Theoretical Equation ◽  
Physical Parameters ◽  
Silty Clay ◽  
Silty Clay Soil ◽  
Gravimetric Water Content

Previous researchers have shown that thermal conductivity and electrical resistivity are related to the water content and void ratio of soil. The objective of this study is to present a theoretical relationship between these two physical parameters. A de Vries equation and Archie’s law are applied to develop a new theoretical equation that relates thermal conductivity to the electrical resistivity of soil. The DRE-2C thermal conductivity tester, which uses a transient plane-source method, is used to measure the thermal conductivity. In addition, the DDC-8 resistivity meter is used to measure the electrical resistivity. Experiments on the thermal conductivity and electrical resistivity of silt soil and silty clay soil with different gravimetric water contents and densities are performed. The results indicate that the theoretical equation can well explain the relationship between the thermal conductivity and electrical resistivity of silt and silty clay soils. The thermal conductivity and electrical resistivity are also found to have a linear relationship with the density of silt soil. When the gravimetric water content is less than 30%, the thermal conductivity and electrical resistivity of silty clay soil increase linearly with the density. The thermal conductivity increases with the gravimetric water content to a critical threshold depending on the soil type. The silty clay samples with a water content of 20% have the largest value of thermal conductivity. The electrical resistivity of the silt and silty clay samples decreases rapidly due to the increased pore connectivity and enhanced hydration of ions in soil with the increased water content. The results of the experiments indicate that the new theoretical equation is effective for estimating the soil electrical resistivity from the soil thermal conductivity.

The Photon Attenuation Coefficients and Thermal Conductivity of Volcanic Rocks

2004 ◽  
Vol 59 (12) ◽  
pp. 888-892
Author(s):  
I. Akkurt ◽  
H. T. Ozkahraman ◽  
B. Mavi ◽  
A. Akkurt
Keyword(s):  
Thermal Conductivity ◽  
Attenuation Coefficient ◽  
Wave Velocity ◽  
Volcanic Rocks ◽  
P Wave ◽  
Linear Attenuation Coefficient ◽  
Attenuation Coefficients ◽  
P Wave Velocity ◽  
Photon Attenuation

The linear attenuation coefficient (μ cm−1) of photon propogation and the thermal conductivity have been determined for some volcanic rocks, which are commonly used materials in building constructions especially as a cladding stone. The linear attenuation coefficient calculated using XCOM is compared with the measurement. Thermal conductivity has been extracted from P-Wave velocity measured using a Pundit apparatus. The relation between thermal conductivity and the attenuation coefficient are also investigated.

Sign in / Sign up

Export Citation Format

Share Document