• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.129-134
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• 2012

Research was focused on the improvement of poor drainage problems on golf course fairway which had not been performed soil test or properly amended during the course construction. The analysis of the drainage problem basically was caused by a deterioration of soil physical properties by the top layer compaction. The soil hardness reached about 3,000 Kpa around 5~6 cm of soil profile. The slow infiltration speed to subsoil by the compaction was caused directly a poor drainage capacity. However, the properly amended sand soil showed an apparent value of 1,500 Kpa through the subsoil. The water content test showed a similar result that higher rate of 20~30% and ideal rate of 8~12% at poor drainage area and successfully amended area, respectively. However, an imported topsoil media which had higher content of silt and clay from a trans-planted sod had made a heterogeneous soil profile and that caused a poor drain capacity by a low infiltration rate. Those drainage problems triggered to buildup a reduced soil layer by poor soil gas exchange. The soil environment of deoxidation enhanced anaerobic microbial population and induced methane gas build-up to 55 ppm, and that resulted an adverse effect on turf growth by root growth retardation, consequently.

• Journal of the Korean Geosynthetics Society
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• v.14 no.2
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• pp.45-55
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• 2015

In Incheon area, 1960s of economic development planning and heavy industry center of efforts industrial park and port facilities, It is industrial land reclamation by coastal landfill, these industrial park has the characteristics of Low permeability lipid is embedded in the silty sand that was dredged. In this study, To evaluate the heavy metal adsorption ability to filter of drains that have been developed as environmentally friendly materials by applying the effective zeolite to heavy metal adsorption for soil pollution purification suitable for geological characteristics of Incheon. soil pollution Survey data and Literature search, which is the current through the industry, the most problematic was set to Cadmium (Cd) and Copper(Cu), Lead (Pb). and Using the Numerical Analysis using the Visual Modflow, was presented the most efficient drains set interval and format.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.155-162
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• 1990

In analysis of deformation in which the stiffness is greatly different between the adjacent materials, the desired results have been obtained by using the interface element method compared with those secured by the conventional method of the concept of continua. However the interface element method was originally developed for the behavior of rocks. This study deals with the deformation analysis of foundation with sand drain by the introduction of interface element. The physical conditions of interface element are devided into three categories by Mohr-Coulomb failure criterion ie. sliding, separation, and contact. Finally the accuracy of the program proposed in this paper is proved highly accurate by performing the comparison of the theoretical values and numerical results of a model element with simplified boundary conditions.

• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.5-12
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• 2016

Stone column is the method that replace soft ground such as weak clay and loose sand with gravel or crushed stone which has relatively high stiffness and low compressive. Stone column increases bearing capacity of the soft ground, reduces settlement, produces ground improvement effect by consolidation drain, and is effective to prevent soil liquefaction in sandy ground during an earthquake. Stone column has been used in many civil works, and has recorded quite a lot of construction achievement internationally, but there is no standardized settlement calculation method yet. Therefore, in this study, the applicability of the existing theoretical equations were evaluated through comparison and analysis to predict a reasonable settlement of the Stone column. Consequently, Hook's law formula was verified to be the most close to numerical analysis.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.307-323
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• 2003

In this study the pilot test of C.G.S (Compaction Grouting System) as injection method by low slump mortar was performed and the results were analyzed in order to find out the application of this method to the soft ground and the effect of settlement restraint. The site for pilot test is adjacent to apartments supported by pile foundations. Sand drain method was performed previously as countermeasures against settlement, but settlement occurs continuously because this ground is very soft. Site investigations such as SPT, CPT and vane shear test were performed to determine the characteristics of ground improvement after the installation of C.G.S. Field measurements were performed on purpose to find out the displacement of ground during the installation of C.G.S. From the results of this study, C.G.S method can be optimized by the control of radius, space, depth, injection material and injection pressure. C.G.S improves soft ground with radial consolidation of adjacent soft ground. Considering that increase of N value to about 3, C.G.S can be considered as an effective method to increase the bearing capacity as well as constrain the settlement of soft ground. It is also expected to be economic and effective in the improvement of ground when it is used in applicable sites.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.93-101
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• 2020

In order to predict the nonlinear behaviour of the soil, the elasto-plastic hyperbolic model was selected, which was considered to be relatively simple and highly predictable. The soil parameter determination and the behavior analysis program were developed by formalizing the functions related to the constitutive model. Each soil parameter was determined from the results of the drained triaxial compression tests of Baekma river sand with the change of relative density. The stress-strain behavior was predicted using the soil parameters determined under each condition. As a result, the deviator stress for the axial strain is verified to have a good match between the measured value and predicted value at each relative density. In the relationship between the volumetric stain and the axial strain, when the relative density is loose, the measured value and predicted value tend to match, and when relative density is dense, the predicted value of the volumetric strain appears somewhat smaller than the measured value due to the limitation of the constitutive model.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.93-104
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• 2002

A field survey and experiment was conducted from 1996 to 1998 to develop rational technology for turfgrass vegetation of runway side of Incheon International Airport on the reclaimed tidal land in Young-Jong Island. Backfill of the experimental site was finished on August 1995. The experimental site was 8 ha located in the middle of the construction place for the main parking lot in front of the terminal building construction. The experimental field was drained by main open ditch, and divided three main plots, no subsurface tile drain, subsurface tile drain spacing with 22.5m, and with 45 m, respectively. The 17 sub plots were designed to test the effect of soil covering with red earth loam by 5 cm and 20 cm depth, application of chemical compound fertilizers and livestock manures, dressing of artifical soils and hydrophylic soil conditioners. The tested turfgrasses were three transplanting indigenous turfgrasses, Zoysia koreana, Zoysia sinica and Zoysia japonica, and two hydroseeding mixed exotic turgrasses, cool type I(tall fescue 30%, kentucky blue grass 40%, perenial ryegrass 30%), and cool type II(tall fescue 40%, perenial ryegrass 20%, fine fescue 20%, alkaligrass 20%). The soil backfilled with dredged seasand was sand textured with high salt concentration and low fertility. The soil showed high pH, low organic matter and low available phophate contents. The percolation rate was fast with high hydraulic conductivity. Desalinization was fast after installation of the main open drainage system. No subsurface tile drainage effect was found showing little difference in turfgrass growth. The covering and visual growth of turfgrasses were the best in the 20-cm soil covering with compound fertilizer treatment. The covering and visual growth of turfgrasses were satisfactory in the 5 cm soil covering with compound fertilizer treatment and with livestock manure treatments. The hydrophillic soil conditioner treatments were effective but expensive at present. The coverage and visual quality of turfgrasses were good for Zoysia koreana and Zoysia japonica. The coverages of turfgrasses by the hydroseeding with the mixed exotic turfgrasses were less than transplanting of native turfgrasses. In conclusion, for the runway side vegetation purposes, the subsurface tile drainage might not necessary as main open ditch drainage be sufficient due to fast percolation rate of the backfilled dredged seasand. The 5 cm soil covering with red earth might be sufficient for the runway side, but the 20 cm soil covering might be necessary for the runway side where high density of turfgrass coverage was necessary to protect from the airplance air blow.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.102-115
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• 2014

The stamped earth method is a typical ancient engineering technique which consists of in-filling wooden frame with layers of stamped earth or sand. This method has been universally used to construct earthen walls and buildings, etc. The purpose of this article is to understand the construction method and principles of the stamped earthen wall through analysis of various construction techniques of Pungnaptoseong Fortress(Earthen Fortification in Pungnap-dong). First of all, the ground was leveled and the foundations for the construction of the earthen wall were laid. The underground foundation of the earthen walls was usually constructed by digging into the ground and then in-filling this space with layers of mud clay. Occasionally wooden posts or paving stones which may have been used to reinforce the soft ground were driven in. The method of adding layers of stamped earth at an oblique angle to either side of a central wall is the most characteristic feature of Pungnaptoseong Fortress. Even though the traces of fixing posts, boards, and the hardening of earth - all signatures of the stamped earth technique - have not been identified, evidence of a wooden frame has been found. It has also been observed that this section was constructed by including layers of mud clay and organic remains such as leaves and twigs in order to strengthen the adhesiveness of the structures. The outer part of the central wall was constructed by the anti-slope stamped earth technique to protect central wall. In addition a final layer of paved stones was added to the upper part of the wall. These stone layers and the stone wall were constructed in order to prevent the loss of the earthen wall and to discharge and drain water. Meanwhile, the technique of cementing with fire was used to control damp and remove water in stamped earth. It can not be said at present that the stamped earth method has been confirmed as the typical construction method of Korean ancient earthen walls. If we make a comparative study of the evidence of the stamped earth technique at Pungnaptoseong Fortress with other archeological sites, progress will be made in the investigation of the construction method and principles of stamped earthen wall.