Bo-An Jang

Correlation of in situ modulus of deformation with degree of weathering, RMR and Q-system

Geotechnical investigation projects in Korea produced data on the in situ modulus of deformation of rock masses (EM) measured with the borehole test, rock mass rating (RMR), and Q-system. The modulus of deformation of rock masses was correlated with the degree of weathering, RMR, and Q values. Determination of EM for each degree of weathering allows for the results to be used to classify the degree of weathering or to predict EM. The relation between EM and RMR is represented by

Paleostress from Healed Microcracks and Fluid Inclusions in Quartz of the Jurassic Granites in the Southwestern Ogcheon Folded Belt

E_{\text{M}} = 10^{{\frac{{{\text{RMR}} - 16}}{50}}}

Influence of microbial activity on the physical properties and strength of ilmenite and magnetite ores

, which returns values 2–3 times lower than those reported in previous studies. Despite scatter in the values, due to larger dataset used in this study, the proposed equation may be used to predict the in situ modulus of deformation from RMR values. In addition, the relation between modulus of deformation and Q values is

Determination of Joint Roughness Coefficients Using Roughness Parameters

E_{\text{M}} = 10^{{0.32{ \log }Q + 0.585}}

Paleostress fields from calcite twins in the Pyeongan Supergroup, South Korea

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Empirical rock mechanical site-descriptive modeling (RMSDM) for the Korea Atomic Energy Research Institute Underground Research Tunnel (KURT)

In order to examine paleostress and tectonic implications, calcite twins in limestone distributed in South Korea were used. The average twin thickness and intensity increase with increasing the total twin strain. Calcite twins in the study area as an indicator of deformation temperature might be produced at temperatures lower than 200°C approximately, being considered for the total twin strain, the average twin thickness and intensity and morphology of calcite. The maximum shortening axes calculated from calcite twins show the NE-SW or NEE-SWW, NW-SE or NWW-SEE and N-S or NNW-SSE directions. These maximum shortening directions are consistent with many fault directions developing in the study area, in particular with the NE-SW main tectonic direction in the Korean Peninsula. Paleostress results from present and other previous studies suggest that the NE-SW maximum shortening direction during the Late Permian to Early Triassic Songrim orogeny in the Korean Peninsula can be compatible with the Indosinian orogeny in China and the Sangun orogeny in the Japanese Island. The NW-SE maximum shortening direction during the Jurassic to Early Cretaceous Daebo orogeny can be compatible with the Yanshanian orogeny in China and the Hida orogeny in the Japanese Island and the N-S maximum shortening direction during the Late Cretaceous to Early Tertiary Bulgugsa orogeny can be compatible with the Sichuanian orogeny in China.