• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.565-570
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• 1996

The landslide survey in an area of about 10 ha was carried out in Hyuseok-dong. Youngchoon-myeon, Danyang-gun, Choongcheongbuk-do. The results showed that there were many indications on geographical changes, such as scars, depressions, upheavals, cracks and destructions of the construction features. The mean degree of slope of the study area was $28^{\circ}$. The results of surface displacement in this area showed that landslide mass is moving in the direction of SE~SEE, and horizontal and vertical movement rate of the center of moving mass was about 1.2m/year and 0.86m/year, respectively. It was estimated that the amount of the soil erosion in the cliff at the lower edge of this area was 0.823m due to the caving erosion by the Namhangang(River) from June through November, 1995.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.111-119
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• 2019

Due to certain geological characteristics (high thickness, rocky properties), some underground coal mines require the use of explosives. This paper explores the effects of fragmentation of different decks detonated simultaneously in a single borehole with the use of numerical analysis. ANSYS/LS-DYNA code was used for the implementation of the models. The models include an erosion criterion to simulate the cracks generated by the explosion. As expected, the near-borehole area was damaged by compression stresses, while far zones and the free surface of the boundary were subjected to tensile damage. With the increase of the number of decks in the borehole, different changes in the fracture pattern were observed, and the superposition effects of the stress wave became evident, affecting the fragmentation results. The superposition effect is more evident in close distances to the borehole, and its effect attenuates when the distance to the borehole increase.