https://repository.kopri.re.kr/handle/201206/11602 2026-04-21T10:26:38Z 2026-04-21T10:26:38Z Park, Keunbo Lee, Bang Yong Lee, Kichoel Kim, Dongwook https://repository.kopri.re.kr/handle/201206/13063 2022-03-24T07:14:56Z 2020-05-01T00:00:00Z

Title: Analysis of Effects of Rock Physical Properties Changes from Freeze-Thaw Weathering in Ny-Alesund Region: Part 2―Correlations and Prediction of Weathered Properties Authors: Park, Keunbo; Lee, Bang Yong; Lee, Kichoel; Kim, Dongwook Abstract: From the examination of rock physical parameters’ changes of compressive strength, shore hardness, water absorption, P-wave velocity with increasing freeze？thaw cycles, correlations of these parameters were investigated. Rock samples were collected from Ny-Alesund region in Norway. As compressive strength and shore hardness inherently have high uncertainties due to inhomogeneous rock composition and internal fissures and cracks, only the relationship between water absorption and P-wave velocity revealed high correlations, providing meaningful linear fitting equations. From the correlation analysis results and clear trends of increasing water absorption and decreasing P-wave velocity with increasing freeze？thaw cycle found in part one of the companion study, prediction equations of future changes of rock physical parameters are proposed using P-wave velocity or water absorption. In addition, future rock weathering grade changes with time can be predicted from estimation of water absorption or P-wave velocity change due to freeze-thaw cycles.

2020-05-01T00:00:00Z Park, Keunbo Kim, Kiju Lee, Kichoel Kim, Dongwook https://repository.kopri.re.kr/handle/201206/13062 2022-03-24T07:15:32Z 2020-03-01T00:00:00Z

Title: Analysis of Effects of Rock Physical Properties Changes from Freeze-Thaw Weathering in Ny-Alesund Region: Part 1―Experimental Study Authors: Park, Keunbo; Kim, Kiju; Lee, Kichoel; Kim, Dongwook Abstract: In order to investigate the weathering characteristics of rocks in response to freeze-thaw conditions in northern latitudes, we analysed meteorological data from the Ny-Alesund region in Norway, and observed changes in the physical and mechanical properties of rocks of dolomite and quartzite. To assess the effects of freeze-thaw weathering on these rock properties, 900 cycles of long-term freeze-thaw tests were conducted for the sampled rocks in two locations. P-wave velocity, absorption, shore hardness, and the uniaxial compressive strength of the sampled rocks were measured at every 150 cycles in order to analyse physical and mechanical mediator variables of freeze-thaw weathering. It was found that an increasing number of freeze-thaw cycle on the sampled rocks decreases uniaxial compressive strength, shore hardness, and P-wave velocity and increases absorption.

2020-03-01T00:00:00Z Park, Keunbo Kim, Yongwon Lee, Kichoel Kim, Dongwook https://repository.kopri.re.kr/handle/201206/13042 2022-03-24T07:15:32Z 2020-02-01T00:00:00Z

Title: Development of a Shallow-Depth Soil Temperature Estimation Model Based on Air Temperatures and Soil Water Contents in a Permafrost Area Authors: Park, Keunbo; Kim, Yongwon; Lee, Kichoel; Kim, Dongwook Abstract: A model for predicting shallow depth soil temperatures is important and effective to assess the changes in soil conditions related to global climate change and local disturbances. Shallow-depth soil temperature estimation model in cold region in Alaska is developed based on thermal response using air temperature and shallow-depth soil water content during active layer development period of 160 days from May to October. Among the seven soil temperature measurement sites, data from four sites were used for model development, and the remaining three sites were used for model validation. Near the middle of the seven measurement sites, air temperature is monitored at one location. The proposed model implemented concepts of thermal response and cumulative temperature. Temperatures and soil water contents were measured using automated remote sensing technology. Consequently, it was confirmed that the developed model enables fast and accurate assessment of shallow-depth soil temperature during active soil layer development period.

2020-02-01T00:00:00Z