Importance of vapor flow in unsaturated freezing soil: A numerical study

Zhang, S; Teng, J; He, Z; Sheng, D

Importance of vapor flow in unsaturated freezing soil: A numerical study

Zhang, S Teng, J He, Z Sheng, D

Permalink

Publisher:: ELSEVIER
Publication Type:: Journal Article
Citation:: Cold Regions Science and Technology, 2016, 126, pp. 1-9
Issue Date:: 2016-06-01

Closed Access

	Filename	Description	Size
	1-s2.0-S0165232X1630026X-main.pdf	Published version	1.31 MB		View/Open

Copyright Clearance Process

Recently Added
In Progress
Closed Access

This item is closed access and not available.

Full metadata record

Field	Value	Language
dc.contributor.author	Zhang, S
dc.contributor.author	Teng, J
dc.contributor.author	He, Z
dc.contributor.author	Sheng, D https://orcid.org/0000-0002-1665-6931
dc.date.accessioned	2022-08-11T06:20:45Z
dc.date.available	2022-08-11T06:20:45Z
dc.date.issued	2016-06-01
dc.identifier.citation	Cold Regions Science and Technology, 2016, 126, pp. 1-9
dc.identifier.issn	0165-232X
dc.identifier.issn	1872-7441
dc.identifier.uri	http://hdl.handle.net/10453/159944
dc.description.abstract	The role of vapor flow in unsaturated freezing soils is unclear, and usually ignored when analyzing water migration. Indeed, vapor flow is seldom considered in geotechnical design. On the other hand, frost heave damages were recently observed in a cold and arid region in China, where the groundwater table is about 20 m deep, and cannot be explained using the classical frost heave theory which focuses on the coupled flow of heat and liquid water. This paper presents a new approach for modeling moisture and heat movement in unsaturated freezing soils, in which the phase change of evaporation, condensation of vapor flow are taken into account. The method enables numerically stable solutions with energy and mass conservation. The performance of the proposed model was evaluated by a series of laboratory freezing experiments, which involve a 60 cm long soil column subjected to different initial conditions and boundary temperatures. It is shown that the proposed model is capable of effectively simulating the freezing process of an unsaturated soil. The vapor flux is shown to be significant, especially at the end stage where the freezing process is stabilized. Parametric analysis was carried out to clarify the role of vapor in moisture migration. The results show that vapor flow apparently contributes to ice formation and generally accounts for more than 10% of total water flux. The percentage of vapor flux in total flux (vapor flux ratio) positively relates to temperature gradient and freezing depth, but negatively relates to initial water content. Relations between vapor flux ratio and hydraulic parameters are less clear.
dc.language	English
dc.publisher	ELSEVIER
dc.relation.ispartof	Cold Regions Science and Technology
dc.relation.isbasedon	10.1016/j.coldregions.2016.02.011
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject	0904 Chemical Engineering, 0905 Civil Engineering, 0911 Maritime Engineering
dc.subject.classification	Meteorology & Atmospheric Sciences
dc.title	Importance of vapor flow in unsaturated freezing soil: A numerical study
dc.type	Journal Article
utslib.citation.volume	126
utslib.for	0904 Chemical Engineering
utslib.for	0905 Civil Engineering
utslib.for	0911 Maritime Engineering
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Civil and Environmental Engineering
utslib.copyright.status	closed_access	*
dc.date.updated	2022-08-11T06:20:44Z
pubs.publication-status	Published
pubs.volume	126

Abstract:

The role of vapor flow in unsaturated freezing soils is unclear, and usually ignored when analyzing water migration. Indeed, vapor flow is seldom considered in geotechnical design. On the other hand, frost heave damages were recently observed in a cold and arid region in China, where the groundwater table is about 20 m deep, and cannot be explained using the classical frost heave theory which focuses on the coupled flow of heat and liquid water. This paper presents a new approach for modeling moisture and heat movement in unsaturated freezing soils, in which the phase change of evaporation, condensation of vapor flow are taken into account. The method enables numerically stable solutions with energy and mass conservation. The performance of the proposed model was evaluated by a series of laboratory freezing experiments, which involve a 60 cm long soil column subjected to different initial conditions and boundary temperatures. It is shown that the proposed model is capable of effectively simulating the freezing process of an unsaturated soil. The vapor flux is shown to be significant, especially at the end stage where the freezing process is stabilized. Parametric analysis was carried out to clarify the role of vapor in moisture migration. The results show that vapor flow apparently contributes to ice formation and generally accounts for more than 10% of total water flux. The percentage of vapor flux in total flux (vapor flux ratio) positively relates to temperature gradient and freezing depth, but negatively relates to initial water content. Relations between vapor flux ratio and hydraulic parameters are less clear.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/159944