• Journal of the Korean GEO-environmental Society
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• v.7 no.3
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• pp.77-83
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• 2006

The purpose of this study is to analyze lateral displacement behavior of clay layers in case of the banking in soft ground through model tests. Seven model tests varying with thickness of soft clay and loading velocity are performed to correlate between ground heaving and loading velocity. In case of low loading velocity, vertical settlement below loading plate and small ground heaving are obviously observed. In case of the high loading velocity, it is shown that both soil displacement at the end of a loading plate and surface heaving are large. In addition, the calculated displacements show good agreement with three cases of field measurements in clay with high moisture contents so that we can predict the range of heaving area and the amount of heaving.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.63-69
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• 2004

During and after the construction of embankment on soft ground, consolidation settlements and lateral displacements develop. But generally it's very difficult to predict the magnitude of lateral deformations and the correct distribution of lateral displacements with depth under the toe of embankment because the consolidation and the shear deformations of soft ground occur simultaneously. This study shows that later displacements of ground surface arise by embankment loading act on soft clay hight water contents in laboratory model testing. The results of model test are observed settlement of embankment, amount of maximum rising and displacement of ground surface with loading velocity. The formula were proposed to predict lateral movement by test series.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.75-84
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• 2020

This paper described the analysis result on heaving of soft ground with DCM column type, based on the results of laboratory model tests on the soft ground with DCM column. The heave characteristics of the soft ground were evaluated according to the application of DCM column in soft ground. The results showed that the heaving of soft ground without DCM column occurred rapidly when the lateral deformation of soft ground increased significantly under the 4th load step condition. In addition, the heaving of soft ground in final load step caused tensile failure of the ground surface. The maximum heaving of the soft ground with the DCM column occurred in the final load step, and the heaving quantity decreased in the order of pile, wall, and grid type. Especially, the soft ground with DCM of grid type effectively resisted ground heaving, even if it was extremely failure in the bottom ground of embankment. The results of the maximum heaving according to the measurement point showed that the heaving of the soft ground with DCM of grid type was 3.1% and 1.6% compared to that of the pile and wall type at the location of LVDT-1, and the heaving of the LVDT-2 position was 1.0% and 2.1%, respectively.

• Journal of the Speleological Society of Korea
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• no.48
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• pp.9-16
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• 1996

석회동굴은 유구한 지구 표면 지층의 역사를 되새겨 주는 석회암 층에서 형성되는 지하동굴이다. 바다 속에서 퇴적되어 형성된 석회암 층이 융기 작용으로 지표면에 상승되어 이른 바 석회암 지표 층을 이루고 있는 곳에서는 빗물에 의한 화학작용으로 땅 표면에서 카르스트 윤회과정의 갖가지 지형지물이 발달되는데, 이 때에 지하에 스며든 지하수의 물리 작용으로 곧 지하수류가 흘러 지나간 공동이 생기게 되고, 나아가서는 낙반 및 확장 등으로 지하동굴이 확장되는데, 2차적인 지하수 침투작용으로 석회질 용해수에 의한 2차 생성물이 형성되어 이른 바 화려한 석회동굴이 이루어진다. 그 석회암의 화학 성분 여하에 따라, 그리고 지하수의 지하 투수량에 따라 석회동굴의 양상은 달리 나타나게 된다.

• Geotechnical Engineering
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• v.10 no.2
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• pp.109-120
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• 1994

One of problems being faced during construction of soil structures along the coastal regions is the stabilization of soft clay foundation, In this study, centrifugal model bests were conducted to investigate behavior effect of soft foundation reinforced by cement -soil piles for the stabilization of softs clay foundation during the embankment construction. This paper presents results of settlement and heaving behavior of reinforced and unreinforced foundation with time under the swaged loading for different best conditions. The test results have shown that the reductions of vertical settlement of the foundation and heaving of the ground surface adjacent to the embankment are greatly influenced by strength of improved pile, and moisture content, and especially the ratio of replacement area.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.125-131
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• 2021

This study described the relationship of settlement-lateral displacement and settlement-heaving according to the DCM type using the model test results, in order to evaluate the behavioral characteristics of the soft ground improved with DCM. As a result, it was found that the total settlement of the model ground was relatively small in the soft ground, to which the DCM was applied, and the settlement was less in the order of the grid type, wall type, and pile type under the same load conditions. This trend was also the same for the lateral displacement and heaving. In addition, the relationship between settlement and lateral displacement of soft ground was analyzed to be similar to that of previous study (Leroueil et al., 1990). Therefore, the DCM of grid type was evaluated to be superior to other types for lateral flow and heaving in the improvement effect of soft ground.

• Journal of the Speleological Society of Korea
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• no.84
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• pp.53-66
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• 2008

오늘날 기후지형학은 지형학자들에게 가장 큰 논점이 되고 있다. 기후적인 외인적인 요인이 제1차적인 형성요인이며, 2차적으로 육수와 해수에 의한 내인적인 발달요인이 된다. 카르스트의 기후 적 접근은 1950년대부터 활발하게 주장되어 현대 진화의 광대한 연구에 가담하였다. 기후적인 작용에 의한 카르스트의 발달은 지대한 영향을 가져오지만 기온에 대한 카르스트의 발달에 대한 논쟁은 기존의 우 열대 저 한대 편향에서 많은 논쟁을 야기시키고 있다. 왜냐하면 한대와 온대, 열대와 중위도 카르스트 간에 어떠한 차이가 있지 않다고 규정짓고 있기 때문이다. 이에 따라 한반도에서도 제4기 동안에 형성된 해수면의 승강작용과 태백산맥의 융기작용에 따른 카르스트의 발달은 지형발달에 지대한 영향을 미친 결과 다수의 지표면 카르스트(카렌)와 지하 동공(동굴)의 발달이 형성되었다.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.389-410
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• 2016

Wide ranges of fission-track (FT) ages were obtained from the Jurassic granite batholith in Jeonju-Gimje-Jeongeup area, southwestern Okcheon Belt: sphene=158~70 Ma; zircon=127~71 Ma; apatite=72~46 Ma. Thermochronological analyses based on undisturbed primary cooling and reset or partially-reduced FT ages, and some track-length data reveal complicated thermal histories of the granite. The overall cooling of the batholith is characterized by a relatively rapid earlier-cooling (${\sim}20^{\circ}/Ma$) to $300^{\circ}C$ isotherm since its crystallization and a very slow later-cooling ($2.0{\sim}1.5^{\circ}/Ma$) through the $300^{\circ}C-200^{\circ}C-100^{\circ}C$ isotherms to the present surface temperature. It is indicated that the large part of Jurassic granitic body experienced different level of elevated temperatures at least above $170^{\circ}C$ (maximum>$330^{\circ}C$) by a series of igneous activities in late Cretaceous. Consistent FT zircon ages from duplicate measurements for two sites of later igneous bodies define their formation ages: e.g., quartz porphyry=$73{\pm}3Ma$; diorite=$73{\pm}2Ma$; rhyolite=$72{\pm}3Ma$; feldspar porphyry=$78{\pm}4Ma$ (total weighted average=$73{\pm}3Ma$). Intrusions of these later igneous bodies and pegmatitic dyke swarms might play important roles in later thermal rise over the study area including hot-spring districts (e.g., Hwasim, Jukrim, Mogyokri, Hoebong etc.). On the basis of an assumption that the latercooling of granite batholith was essentially controlled by the denudation of overlying crust, the uplift since early Cretaceous was very slow with a mean rate of ~0.05 mm/year (i.e., ~50 m/Ma). Estimates of total uplifts since 100 Ma, 70 Ma and 40 Ma to present-day are ~5 km, ~3.5 km and ~2 km, respectively. The consistent values of total uplifts from different locations may suggest a regional plateau uplift with a uniform rate over the whole granitic body.

• Tunnel and Underground Space
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• v.25 no.2
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• pp.155-167
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• 2015

The thermal-hydrological-mechanical (T-H-M) behavior of rock mass surrounding a high-temperature cavern thermal energy storage (CTES) operated for a period of 30 years has been investigated by TOUGH2-FLAC3D simulator. As a fundamental study for the development of prediction and control technologies for the environmental change and rock mass behavior associated with CTES, the key concerns were focused on the hydrological-thermal multiphase flow and the consequential mechanical behavior of the surrounding rock mass, where the insulator performance was not taken into account. In the present study, we considered a large-scale cylindrical cavern at shallow depth storing thermal energy of $350^{\circ}C$. The numerical results showed that the dominant heat transfer mechanism was the conduction in rock mass, and the mechanical behavior of rock mass was influenced by thermal factor (heat) more than hydrological factor (pressure). The effective stress redistribution, displacement and surface uplift caused by heating of rock and boiling of ground-water were discussed, and the potential of shear failure was quantitatively examined. Thermal expansion of rock mass led to the ground-surface uplift on the order of a few centimeters and the development of tensile stress above the storage cavern, increasing the potential of shear failure.

• The Journal of Engineering Geology
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• v.11 no.2
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• pp.175-190
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• 2001

This study investigates the existing theoretical backgrounds in order to examine the behavior of lateral flow according to the plasticity of soils when unsymmetrical surcharge is worked on polluted soft soils by comparing and analyzing the results measured through model tests. Model tests are canied out as follows soil tank, bearing frame and bearing plate are made. By increasing unsymmetrical surcharge to the ground soils with the consistent water content and with gradually increased polluted materials at intervals, the amounts of settlement, lateral displacement and upheaval were respectively observed. In conclusion, the value of critical surcharge was expressed as q$_{cr}$=2.78$_{cu}$ which was similar to those Tschebotarioff(q$_{cr}$=3.0$_{cu}$) and Meyerhof(q$_{cr}$=(B/2H+$\pi$/2)$_{cu}$) had been proposed. The value of ultimate capacity was expressed as q$_{ult}$=4.84$_{cu}$ which was similar to that of Prandtl. The lateral flow pressure is adeQuately calculated by the eQuation(P$_{max}$=K$_o$ r H) and the maximum value of lateral flow pressure is found near O.3H of layer thickness(H) and is higher to ground surface than the ones in composition pattern, Poulos distribution pattern and softclay soils (CL, CH) which is not polluted. The stability control method used in this research followed the management diagram of Tominaga.Hashimoto, Shibata.Sekiguchi, Matsuo.Kawamura who use the amounts of plasticity displacement by lateral flow. As a result, the ultimate capacity values in the diagram {S$_v$-(Y$_m$/S$_v$)} of Matsuo.Kawamura and in the diagram {(q/Y$_m$)-q} of Shibata. Sekiguchi were smaller than in the ones of load-settlement curve (q-S$_v$).