Basic Research on Low Temperature Materials Storage in Openings Excavated in Tuff Mountain

Naoto KAMOSHIDA* and Masafumi OKAWARA** Currently, the effect of pore water on the thermal diffusivity of rocks at low temperatures is unclear. In this study, the thermal diffusivities of Berea sandstone (12.8%-porosity) and Himekami granite (1.09%) were measured using an optional heating method. Consequently, the change in the thermal diffusivity of saturated Himekami granite (approximately 100%-water saturation) increased continuously and gradually, as observed in dry granite (approximately 0%). However, when cooling from room temperature to −10°C, the thermal diffusivity of saturated Berea sandstone increased discontinuously and rapidly, in contrast to the dry sandstone in which it increased continuously and gradually. Subsequently, the effect of porosity and pore structure on the thermal diffusivity of saturated rocks was examined during the freezing process by comparing the results of Kimachi sandstone (20.2%-porosity) and Ogino tuff (28.7%) measured using the same method by the Kamoshida et al. (2013). Results show that the change in the thermal diffusivity during the cooling process of saturated rocks is depended by the pore structure (pore size distribution) instead of the rock's water content (porosity). Therefore, rocks containing macropores, such as Berea and Kimachi sandstones, can be assumed particle-dispersed complexes (the rock-forming minerals are the matrix, and the pores are the particles). Thus, the changed behavior of thermal diffusivity during the cooling process can be estimated by measuring the pore size distribution and thermophysical properties of rock-forming minerals.

show abstract

Mechanical Behavior of Kimachi Sandstone under Ultralow Temperature

Kamoshida

Okawara

Abe

et al. 2010

Journal of the Mining and Materials Processing Institute of Jap

View full text Add to dashboard Cite

The practical application of the rock cavern storage of liquefied fuels (such as natural gas, liquid hydrogen or dimethyl ether) requires stability analysis of the cavern in question with regard to thermal stress, and an understanding of thermophysical properties and mechanical properties of rock mass is essential for such analysis.In our research, a linear expansion strain measurement test up to −170℃ was first conducted using Kimachi sandstone (24.0% porosity) to study the relationship between the freezing of pore water and its expansion strain. Then a uniaxial compression test and indirect tensile test were conducted with wet sandstone cooled down below freezing point to ultralow temperatures to review the influence of the formation of pore ice on the strength of wet sandstone. The following findings were obtained.When Kimachi sandstone is cooled down, frost swelling occurs twice, and therefore the linear expansion coefficient fluctuates over range of temperatures between 0 to −70℃ . This may be because pores of two different sizes exist in Kimachi sandstone and the freezing temperature of the pore water differs depending on the pore size. The compressive strength and indirect tensile strength of the wet sandstone increase with the decrease in the specimen temperature. Two causes of this phenomenon may be identified. One is that an increase in pore ice that shares the load is the main cause of the phenomenon in temperatures down to −50℃ where freezing of the pore water is almost completed. The other is that an increase in strength by volumetric shrinkage of the rock forming minerals and pore ice is the main cause in temperatures below −50℃ .

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Basic Research on Low Temperature Materials Storage in Openings Excavated in Tuff Mountain

Cited by 4 publications

References 5 publications

Proposal of Thermophysical Properties Evaluation Method of Bedrock by in-Situ Test and Numerical Analysis Using Characteristics of Underground Space in Oya Area

Proposal of Thermophysical Properties Evaluation Method of Bedrock by in-Situ Test and Numerical Analysis Using Characteristics of Underground Space in Oya Area

Effect of Pore Water on the Thermal Diffusivity of Water-Saturated Rocks at Extremely Low Temperatures

Mechanical Behavior of Kimachi Sandstone under Ultralow Temperature

Contact Info

Product

Resources

About