Change search
ReferencesLink to record
Permanent link

Direct link
Borehole seals of expandable clay with desired water content by use of “dry water”
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
Number of Authors: 4
(English)Article in journal (Refereed) Submitted
Abstract [en]

Dense clay can be used for sealing of boreholes. Keeping the clay confined in perforated tubes it can be inserted in boreholes of nearly any length and diameter. Expansion of the clay to fill the borehole takes place by uptake of water and migration of clay through the perforation. The clay thereby exerts a swelling pressure on the confining rock causing effective sealing. For shallow boreholes to be sealed a very low initial degree of water saturation of the clay may be valuable since this makes the clay expand and seal the hole quickly, but for certain cases the clay should have a higher degree of water saturation. This can be required for moderating the rate of clay densification that may otherwise give too high wall friction for placement in very long holes. Sealing of very deep holes and holes containing highly radioactive waste makes temperature important: the heat-induced expansion of initially fully saturated clay can fracture the confining rock. The issue is therefore to prepare the clay inserts withproperly selected water content. The paper describes preparation of clay seals by mixing air-dry clay powder with nanoparticles of water droplets coated with very thin shells of a hydrophobic silicious substance (“dry water”). It behaves as dry powder and is easily mixed with dry clay. On compaction to the desired density the shells break into aggregates of minute fragments while water becomes homogeneously distributed in the mass. Laboratory and bench-scale testing verify that the properties of clay prepared in this way are the same as of clay saturated by sorbing water through a filter, a process that can take hundreds of years for big samples. Keywords:borehole sealing, clay blocks, degree of saturation, density, “dry water”, water content1. IntroductionSeveral concepts for sealing of boreholes and disposal of radioactive waste make use of dense

National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
URN: urn:nbn:se:ltu:diva-36823OAI: oai:DiVA.org:ltu-36823DiVA: diva2:1010166
Available from: 2016-10-02 Created: 2016-10-02 Last updated: 2016-11-29

Open Access in DiVA

fulltext(474 kB)1 downloads
File information
File name FULLTEXT01.pdfFile size 474 kBChecksum SHA-512
ef0bf44c19f7338b3b632d9e70f2fb7a91757b8f189e370d7e63a9e7f319f28410184c692f473177bd78e2713e1ffe67edb9328710bf8cb67593e5f3b05e2ed7
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Forsberg, ThomasPusch, RolandYang, TingKnutsson, Sven
By organisation
Structural and Fire EngineeringMining and Geotechnical Engineering
Geotechnical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 4 hits
ReferencesLink to record
Permanent link

Direct link