• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.13-21
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• 2000

Detention basin is the temporary holding pond of treated water prior to flow out to the sea. It is very common to dredge the soil from the bottom of detention basin to keep up the water holding capacity. In this study, the amount of volume reduction of dredged soil from detention basin was estimated based on the laboratory test results. The percentage of soil particles in dredged organic soil is about 12.5∼21.9% by weight. The content of heavy metal and environmental effect for dredged soil itself and solidified dredged soil were analysed and the results are meet the standards of environmental requirement.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.119-126
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• 1999

This study was carried out to estimate the effect of forest fire on physical and chemical properties of soil The forest fire was in April 1995 at Kongju of Chungnam. Soil samples were collected at 0~5cm, 5~10cm, and 10~20cm soil depths in September 1998 from the burned and unburned sites. Soil organic matter concentrations at 0~5cm and 5~10cm soil depths were significantly greater in unburned site than in burned site. Soil concentrations were greater in unburned site than in burned site at all soil depths. Cation exchange capacity was significantly higher in unburned site than in burned site at 0~5cm soil depth. There were no differences in available soil P, exchangeable soil K, Ca, and Mg, and pH of soil between burned and unburned sites. Soil water content at 0~5cm soil depth was significantly greater in unburned site than in burned site. Bulk density at 0~5cm soil depth was significantly higher in burned site than in unburned site. Forest fire had an adverse effect on physical and chemical properties of soil in this study, Burning of vegetation and forest 리oor organic matter in burned site may reduce organic matter supply to soil and increase soil erosion. Consequently, forest fire may have adverse influence on long-term site productivity.

• Journal of Biosystems Engineering
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• v.26 no.3
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• pp.245-252
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• 2001

This study was carried out to investigate the effect of three factors(dynamic load, inflation pressure and multiple passes of the tire) on the contact pressure and the soil stresses under the tire. A series of soil bin experiment was conducted with a 6.00R14 radial-ply tire for sandy loam soil. Tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth were measured for the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.69kPa), and for five different number of passes(1, 2, 3, 4 and 5 pass). The following results were drawn from this study 1) As dynamic load, inflation pressure and number of passes of the tire increased, tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth increased accordingly. Thus increased in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2) The effect of three different factors, or dynamic load, inflation pressure and number of passes of the tire, decreased as the soil depth increase. Consequently, it was found that the soil compaction at a shallow depth in soil is larger than that at deep place in soil. 3) The increase of dynamic load and number of passes increased soil stress exponentially, but the increase of inflation pressure increased soil stress linearly. The effect of tire inflation pressure on soil stress was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load is more important factor affecting soil compaction in comparison to the inflation pressure of tire.

• Earthquakes and Structures
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• v.24 no.5
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• pp.345-352
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• 2023

This paper studied the effect of soil-structure interaction (SSI) on the seismic response and retrofit of a reinforced concrete structure with a soft-first story for different soil types. A 5-story structure built on a 30m deep homogeneous soil mass was considered as a case study structure, and steel column jacketing and steel bracing were chosen as seismic retrofit methods. Seismic responses of a fixed-base and a flexible base structure subjected to seven scaled earthquake records were obtained using the software OpenSees to investigate the effect of soil on seismic response and retrofit. The nonlinearBeamColumn elements with the fiber sections were used to simulate the nonlinear behavior of the beams and columns. Soil properties were defined based on shear wave velocity according to categorized site classes defined in ASCE-7. The finite element model of the soil was made using isoparametric four-noded quadrilateral elements and the nonlinear dynamic responses of the combined system of soil and structure were calculated in the OpenSees. The analysis results indicate that the soil-structure interaction plays an important role in the seismic performance and retrofit of a structure with a soft-first story. It was observed that column steel jacketing was effective in the retrofit of the model structure on a fixed base, whereas stronger retrofit measures such as steel bracing were needed when soil-structure interaction was considered.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.281-281
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• 2015

Shallow landslide often occurs in areas of this topography where subsurface soil water flow paths give rise to excess pore-water pressures downslope. Recent hillslope hydrology studies have shown that subsurface topography has a strong impact in controlling the connectivity of saturated areas at the soil-bedrock interface. In this study, the physically based SHALSTAB model was used to evaluate the effects of three soil thicknesses (i.e. average soil layer, soil thickness to weathered soil and soil thickness to bedrock soil layer) and subsurface flow reflecting three soil thicknesses on shallow landslide prediction accuracy. Three digital elevation models (DEMs; i.e. ground surface, weathered surface and bedrock surface) and three soil thicknesses (average soil thickness, soil thickness to weathered rock and soil thickness to bedrock) at a small hillslope site in Jinbu, Kangwon Prefecture, eastern part of the Korean Peninsula, were considered. Each prediction result simulated with the SHALSTAB model was evaluated by receiver operating characteristic (ROC) analysis for modelling accuracy. The results of the ROC analysis for shallow landslide prediction using the ground surface DEM (GSTO), the weathered surface DEM and the bedrock surface DEM (BSTO) indicated that the prediction accuracy was higher using flow accumulation by the BSTO and weathered soil thickness compared to results. These results imply that 1) the effect of subsurface flow by BSTO on shallow landslide prediction especially could be larger than the effects of topography by GSTO, and 2) the effect of weathered soil thickness could be larger than the effects of average soil thickness and bedrock soil thickness on shallow landslide prediction. Therefore, we suggest that using BSTO dem and weathered soil layer can improve the accuracy of shallow landslide prediction, which should contribute to more accurately predicting shallow landslides.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.120-127
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• 2001

Long term earthquake observations at different tunnel sites within a variety of alluvial soil deposits have demonstrated that a circular tunnel is liable to deform in such a way that its two diagonal diameters crossing each other expand and contract alternately. Based on this knowledge, the soil-tunnel interaction and isolation effect for this particular vibration mode is investigated. Interaction effect is considered with the condition of fixed tangential strain between the tunnel and the soil. Isolation effect embodied by covering up the tunnel with isolation materials is discussed as a possible measure for mitigating seismic damage to it. When Poisson`s ratio of isolation material decreases or the shear modulus ratios of the soil to isolation material become large, the isolation effect becomes bigger.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.303-308
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• 1994

We have obtained following results by executing this experiment to define effects of organic substances applied and temperature on fungistatic effect which is regarded as basic factor of inhibition against hot-pepper blight affection : 1. Fungistatic effect of soil on Phytophthora capsici is enlarged by application of organic material such as rice straw rather than matured composts. Morever, it is confirmed that fungistatic efect is more eminent at the temperature of $15^{\circ}C$ and $5^{\circ}C$ than at $30^{\circ}C$, Degree of fungistatic effect of soil tends to decrease as the goe on from the moment of using organic substance generally, in soil applied as the goes on from the moment of using organic substance generally, in soil applied rice straw it is prove that fungistatic effect is maintained stably in a long term. 2. Effect of applicating organic substances and treating by temperature on production of zoosporangium of Phytophthra capsici is reviewed. In case that sterilized soil solution is added on cultured hypae of Phytophthra capsici, increase in the production of zoosporangium is found which is statistically significant(at degree of 1%), while decrease effect statistically significant is found in case of adding soil solution used for applying bark compost. However, defferences between treatments of temperature is not found. On the other hand, when nonsterilized soil solution is added, significant defference between types of organic substance is not found, while significant difference is found between treatments of temperature, therefore formation of zoosporangium is increased at the condition of $5^{\circ}C$ comparing to that of $30^{\circ}C$. 3. Putting above result of examination concerning to composition of soil microrganisms in each treated soil and to fungistatic effect of them, it seems that fungi and bacteria in soil is mostly related to fungistatic activity of soil.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.161-189
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• 2015

Soil-pile raft-structure interaction is recognized as a significant phenomenon which influences the seismic behaviour of structures. Soil structure interaction (SSI) has been extensively used to analyze the response of superstructure and piled raft through various modelling and analysis techniques. Major drawback of previous study is that overall interaction among entire soil-pile raft-superstructure system considering highlighting the change in design forces of various components in structure has not been explicitly addressed. A recent study addressed this issue in a broad sense, exhibiting the possibility of increase in pile shear due to SSI. However, in this context, relative stiffness of raft and that of pile with respect to soil and length of pile plays an important role in regulating this effect. In this paper, effect of relative stiffness of piled raft and soil along with other parameters is studied using a simplified model incorporating pile-soil raft and superstructure interaction in very soft, soft and moderately stiff soil. It is observed that pile head shear may significantly increase if the relative stiffness of raft and pile increases and furthermore stiffer pile group has a stronger effect. Outcome of this study may provide insight towards the rational seismic design of piles.

• Geomechanics and Engineering
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• v.32 no.4
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• pp.445-452
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• 2023

Temperature is one of the important factors affecting the permeability of water in the soil. In the present study, the impact of water temperature on hydraulic conductivity (k) with and without coarse aggregations by considering six types of soils was analyzed. Moreover, the effect of sand and gravel presence in the soil was investigated through the infiltration based on constant and inconstant water head experiments. Results indicated that by increasing the water temperature, adding gravel to sandy soil caused the hydraulic conductivity to raise. It is supposed that the gravel decreased the contact surface between the water and the soil aggregates. It is deduced that due to decreasing kinetic energy, k tends to have lower values. Furthermore, adding the sand to sandy silt-clay soil showed that the sand did not have a marginal effect on the variation of k since the added sand cannot increase the contact surface like gravel. Finally, increasing the main diameter of the soil will increase the effect of the water temperature on hydraulic conductivity.

• Mycobiology
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• v.40 no.3
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• pp.168-172
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• 2012

In this study, the effect of soil ameliorators on ectomycorrhizal (ECM) fungal communities in coal mine spoils was investigated. Organic fertilizers and slaked lime were applied as soil ameliorators in 3 abandoned coal mine spoils. One year after the initial treatment, roots of Pinus densiflora seedlings were collected and the number of ECM species, colonization rate, and species diversity were assessed. The results showed that the soil ameliorators significantly increased ECM colonization on the roots of P. densiflora. The results suggest that soil ameliorators can have a positive effect on ECM fungi in terms of growth of host plants and show the potential use of soil ameliorator treatment for revegetation with ECM-colonized pine seedlings in the coal mine spoils.