• Economic and Environmental Geology
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• v.57 no.2
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• pp.243-251
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• 2024

In this study, a surface geological survey was first conducted to investigate aggregate resources in the Yeongam area of Jeollanam-do, and a drilling survey was conducted in the lower part of the surface, which was difficult to identify through a surface geological survey, to determine the spatial distribution of aggregates. Drilling sites were selected considering the topographical development and Quaternary alluvium characteristics of the study area, and river aggregate drilling surveys were conducted at a total of 5 points and land aggregate drilling surveys were conducted at a total of 28 points. Borehole core sediments were classified into seven sedimentary units to determine whether they could be used as aggregates, and optically stimulated luminescence dating was performed on representative boreholes to measure the depositional period for each sedimentary unit. As a result of the study, most of the Yeongam area had a very wide river basin, so it was estimated that there would be a large amount of aggregate, but the amount of aggregate was evaluated to be very small compared to other cities and counties. Most of the unconsolidated sedimentary layers in the Yeongam area are composed of blue-grey marine clay with a vertical thickness of more than 10 m. The sand-gravel layer corresponding to the aggregate section is distributed in the lower part of the marine clay, thinly covering the bedrock weathering zone. This is because the amount of aggregates themselves is small and most of the aggregates are distributed at a depth of 10 m below the surface, which is currently difficult to develop, so the possibility of developing aggregates is evaluated to be very low. As a result of dating, it can be seen that the blue-grey marine clay layer is an intertidal sedimentary layer formed as the sea level rose rapidly about 10,000 years ago. The deposition process continued from 10,000 years ago to the present, and as a result, a very thick clay layer was deposited. This clay layer was formed very dominantly for about 6,000 to 8,000 years, and the sand-gravel layer in the section where aggregates deposited in the Pleistocene period can exist was measured to have been deposited at about 13.0 to 19.0 ka, and about 50 ka, showing that it was deposited as paleo-fluvial deposits before the marine transgression process.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.801-810
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• 2010

Until now, design of Earth Retaining is practiced by 2nd dimensional analysis for convenience of analysis and time saving. However, the construction field is 3rd dimension, in this study, practised the 3rd dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2nd and 3rd dimensional analysis. existing 2nd dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3rd dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2nd dimension analysis is underestimated. Moreover, results of 2nd and 3rd dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H, 1.0H and 1.5H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2nd dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3rd dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.181-185
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• 2010

Until now, design of Earth Retaining is practiced by 2 dimensional analysis for convenience of analysis and time saving. However, the construction field is 3 dimension, in this study, practised the 3 dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2 and 3 dimensional analysis. existing 2 dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3 dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2 dimension analysis is underestimated. Moreover, results of 2 and 3 dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H and 1.0H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2 dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3 dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.769-777
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• 2022

Purpose: This study analyzes and studies the characteristics of the Jeju area and uses them as basic data such as construction method design in the future development project. Method: Based on the ground survey data of the construction conducted in Jeju, the depth, relative density, N value, function state, color tone, groundwater level, and compressive strength were analyzed and studied. Result: Studies show that Jeju has columnar joints consisting of ancient volcanic activity and rapid cooling by nearby seawater, thick sand layers found on the coast, and clinker layers and Seogwipo layers formed by Mercury volcanic activity. Conclusion: It is hoped that it will be used as data for selecting basic design and basic construction method by understanding the special ground form of Jeju area and reflecting its characteristics well when designing construction.

• Journal of Korea Water Resources Association
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• v.49 no.9
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• pp.741-748
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• 2016

Laboratory scale model was constructed for open-cut riverbed infiltration experiment and four kinds of media were selected, medium sand, sand, volcanic rock, and gravel, for the experiment. Hydraulic conductivity for each medium and flow rate from the collecting pipe with functional screen were estimated from the experiment. Modified hydraulic conductivity scenarios considering turbid water (30~50 NTU) were applied in Visual MODFLOW modeling to analyze the effects of turbid water on the flow rate. Twenty-two scenarios were generated considering prticles in turbid water and applied to each medium cases in MODFLOW modeling. The minimum error was occurred when the gravel medium had 20% less hydraulic conductivities for the third layer-depth from the top and clay particles in turbid water might play a role in adsorption process to the surface of volcanic rock (2~5 mm). For medium sand case the error was also quite small when the mediumhas 5% less hydraulic conductivities for the second layer-depth from the top.

• Journal of the Korean Geotechnical Society
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• v.26 no.1
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• pp.21-33
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• 2010

In this paper, the consolidation and the permeability characteristics of Songdo were evaluated based on the laboratory and field tests. The test results indicate that silty clay layer above approximately E.L-15 m are consolidation layer, and sand layers embedded in consolidation layers are drainage layers. Consolidation layer was overconsolidated state before the reclamation work; however, it transferred to normalized state after the reclamation work. In addition, the average and the range of consolidation properties and magnitude of anisotropy of coefficient of consolidation were evaluated according to the soil types such as clay, silty, and clayey silt since these properties are sensitive to soil types. These analysis results can be used as preliminary design parameters of consolidation and permeability m Songdo area.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.1
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• pp.87-95
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• 2002

This study was carried out to investigate the load of soil layers affected by soil depth in artificial soil alone or in blends with Loam with various ratio. The artificial soils were perlite large grain, perlite small grain, and perlite small grains blended with Loam (sand 46%, silt 40%, clay 14%) at a ratio of 8:2, 6:4, 5:5 (v/v). The soil layers were divided into a planting layer and a well-drained layer, then the weight of each layer in the air-dried state and in the field capacity were determined. The data were subjected to correlation analysis, regression analysis, and paired samples t-test. The summarized results are as follows; 1) In the air-dried state, the regression equations of the well-drained layer weight(kg/m2) in perlite large grain, planting layer weight in perlite small grain, planting layer weight in perlite small grain biended with loam(8:2, v/v), perlite small grain blended with loam(6:4, v/v), and perlite small grain blended with loam(5:5, v/v) were; 1.65824*X+0.026, 1.52292*X-0.052, 3.21468*X+0.515, 6.17549*X+ 0.083, and 6.02100*X + 33.133, respectively, where X is soil depth measured in Centimeters. 2) In the field capacity, the regression equations of the well-drained layer weight(kg/m2) in perlite large grain, planting layer weight in perlite small grain, planting layer weight in perlite small grain blended with loam(8:2, v/v), perlite small grain blended with loam(6:4, v/v), and perlite small grain blended with loam(5:5, v/v) were 5.055*X - 2.006, 7.073*X + 100.008, 8.092*X + 116.676, 10.766*X + 100.112, and 10.974*X + 124.423, respectively, where X is the soil depth measured in Centimeters. 3) All of the equations mentioned above were statistically reliable and therefore easily applicable in practical business affairs.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.203-210
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• 2004

Consolidation properties were analysed by means of depositional environments. Depositional environments including geochemical properties, porewater chemistry, sediment structures, particle size distributions and carbon age dating were analysed using undisturbed samples retrieved successively from a boring hole in the study area. Laboratory oedometer tests and anisotropic consolidated triaxial tests(CKoUC) were performed to examine the overconsolidation phenomenons. Based on the carbon age dating results and profiles of geochemical properties, porewater chemistry, salinity and pH, it was founded that the upper silt/clay complex layer was deposited under marine condition while sand and clay layers were deposited under fluvial condition. Planar laminated structures of silts and clays were dominant in marine deposits. Although there was no clear evidences that geological erosion had been occurred in marine deposits, overconsolidation ratio obtained from oedometer tests were greater than unity. Stress paths of samples behaved similar to those of normally consolidated clays. Data plotted in stress state charts proposed by Burland(1990) and Chandler(2000) showed that the marine deposits were geologically normally consolidated. These apparent overconsolidations can be explained by the fabric and chemical bonding due to the difference of the rate of deposition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.215-224
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• 1990

Finite element model capable of solving coupled deformation-fluid diffusion equations for the fully saturated porous medium was developed using Galerkin's residual method. This model was used to study the mechanical and hydraulic behaviors of unconsolidated sediment near South Harbor, Pusan. The vertical displacement of top surface clay sediment, when subjected to the external load, is significantly affected by the excessive pore pres- sure buildup and its decay due to the pore fluid diffusion. The sand deposit overlain by the much less permeable clay layer serves as a flow channel. Consequently, the fluid diffusion due to pore pressure difference is significantly facilitated, which also affects the diffusion-dependent sediment deformation.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1234-1242
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• 2010

In this study, the effect of noise and vibration, and influence of ground improvement are evaluated and its application is analyzed through the example of SCP designed at ground improvement in Song-Do international city. consequently, it showes even comfortable result that it is about 5.0m of inner space, when the LVSCP method is applied, rather than that it is about 30m of inner space when the existing SCP is applied in vibration control standards 2.0mm/sec. In the noise, now that the many differences according to environmental factors like other equipment noise, limited space and so on at the time of the construction by LVSCP method are coming out, so we think that appro itate measures are needed according to surroundings. By the way, when it comes to the estimation of the ground improvement work before and after an improvement of LVSCP method, its result shows that it is satisfacttion to all the standards of compaction control in dregded and reclaimed ground and sedimentary clay layer.