• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.286-289
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• 2004

On site, In situ soil remediation technologies are very important among the remediation technologies and in general efficiency of these technologies are turned to site characterization and environmental condition. specially using of only one technology has so many limitation factors. for example, existing state of tailing and channeling and so on. actually, filled land have high concentration cation exchange capacity because of existence in abundance soil organic matter. Therefore we used various on site in Situ technologies by phase for overcome the limitation factors. Target site is petroleum (diesel) impacted filled land and using technologies are SVE(Soil Vapor Extraction), BV(Bioventing), Bioremediation, Soil flushing, Chemical oxidation.

• Geomechanics and Engineering
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• v.20 no.6
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• pp.505-516
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• 2020

In recent years, Nano-technology significantly invaded the field of Geotechnical engineering, particularly in soil stabilisation techniques. Stabilisation of weak soil is envisioned to modify various soil characteristics by the addition of natural or synthetic materials into the virgin soil. In the present study, laboratory experiments were executed to investigate the influence of nano-silica particles in the consistency limits, compressive strength of the soft clay blended with cement. The results revealed that the high compressibility behaviour of soft clay modified to medium-stiff condition with fewer dosages of cement and nano-silica. The mechanism behind the strength development is verified with the previous researches as well as from Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction test (XRD) and Scanning Electron Microscopy (SEM) analysis. Based on the results, the presence of nano-silica in soft clay blended with cement has a positive effect on the behaviour of soil. This technique proves to be very economical and less detrimental to the environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.705-708
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• 2004

The spatial variability of the L- and C- band large scale remotely sensed soil moisture data, obtained during tire Southern Great Plain 1999 (SGP'99), was characterized. The results demonstrate that soil moisture data using L-band show the break in statistical symmetry (multiscaling behavior) with the variation of scale of observation, which is similar to that of the soil property such as sand content. Also, soil moisture data using C-band show single scaling behavior with the variation of scale of observation, which Is similar to that of the vegetation condition.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.1
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• pp.7-11
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• 2002

By focusing on the resonant vibration mode of soil-underground structure system, this paper obtained dynamic soil stiffness and easy sliding conditions at the interface between soil and underground structure. Multi-step method is employed to isolate two primary causes of soil-structure interaction. Mohr-Coulomb criterion is used to determine the threshold level of the sliding. To find out the conditions the interface slides easily, parametric studies are performed about the factors governing sliding, which are the size and location of underground structures, ground condition, the configuration of surface deposit and interface friction coefficients.

• International Journal of Railway
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• v.6 no.2
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• pp.45-52
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• 2013

Railway construction needs vast soil investigation for its infrastructure foundation designs along the planned railway path to identify the design parameters for stability and serviceability checks. The soil investigation data are usually classified and grouped to decide design input parameters per each construction section and budget estimates. Deterministic design method which most civil engineer and practitioner are familiar with has a clear limitation in construction/maintenance budget control, and occasionally produced overdesigned or unsafe design problems. Instead of using a batch type analysis with predetermined input parameters, data population collected from site soil investigation and design load condition can be statistically estimated for the mean and variance to present the feature of data distribution and optimized with a best fitting probability function. Probabilistic approach using entire feature of design input data enables to predict the worst, best and most probable cases based on identified ranges of soil and load data, which will help railway designer select construction method to save the time and cost. This paper introduces two Monte Carlo simulations actually applied on estimation of retaining wall external stability and long term settlement of organic soil in soil investigation area for a recent high speed railway project.

• Computers and Concrete
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• v.22 no.2
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• pp.221-225
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• 2018

In this paper, vibration analysis of concrete foundations resting on soil medium is studied. The soil medium is simulated by Winkler model considering spring element. The concrete foundation is modeled by thick plate elements based on classical plate theory (CPT). Utilizing energy method consists of potential energy, kinetic energy and external works in conjunction with Hamilton's principle, the motion equations are derived. Assuming the simply supported boundary condition for the concrete foundation, the Navier method is used for calculating the frequency of the structure. The effect of different parameters such as soil medium, mode numbers, length to width ratio and length to thickness ratio of the concrete foundation are shown on the frequency of the structure. At the first, the results are validated with other published works in order to show the accuracy of the obtained results. The results show that considering the soil medium, the frequency of the structure increases significantly.

• Geomechanics and Engineering
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• v.38 no.6
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• pp.603-609
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• 2024

In downtown subway project most of excavated soil is discarded externally, whereas in road construction excavated soil is used as filling material and management of surplus soil becomes important factor for success of the project. Excavated materials from slurry shield TBM are discharged through discharge pipe to slurry treatment plant and excavated soil mixed with bentonite are separated in separation plant by grain size. Fine material has been discarded together in filter cake without recycling. Its volume can vary according to geologic condition but statistically fine material as filter cake is about 5%~30% out of overall excavated volume. However, filter cake is non-toxic and can be recycled when mixed in the appropriate proportions with coarse aggregate. Therefore, in this study, utilization of excavated soil from a slurry shield TBM were examined and lab tests were conducted to find the proper way for mixing filter cake and aggregate to be recycled as fill material for road construction.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.149-154
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• 1971

To elucidate the effects of calcium carbonate applied under upland and flooded conditions on the changes of soil pH, an incubation study of a soil was carried out. The experiment was conducted under the conditions with and without ground rice straw application. The results of the experiment are summarized as follows: 1. The incubation under the upland moisture condition after the application of calcium carbonate raised soil pH as high as calcium hydroxide did, whereas incubation with calos treatment under the flooded condition showed a low pH. 2. Reduction of a soil brought about by the application of ground rice straw has a significant effect on the rise of soil pH. The high pH of a soil thus brought about or raised by the use of lime is gradually reduced as the accumulation of bicarbonate ions and carbon dioxide increases in the soil solution. It may, however, be possible to keep the high pH of a flooded soil by practicing intermittent drainage or cultivation which reduces the content of bicarbonate and $CO_2$ pressure in soil solution. 3. Carbonate and bicarbonate salts which may be produced in flooded and reduced soil increases the buffering capacity of the soil.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.109-113
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• 2007

In order to establish the fertilization and soil management method in Gyehwa reclaimed tidal land, we investigated soil property and actual farming condition. Soil properties of 100 field paddy soil and farming surveys of 177 farm households were conducted. Average of effective soil depth was 17.8 cm, which was very smaller than the optimum level 50 cm. The hardness and bulk density of subsoil were $12.40kg\;cm^{-2}$ and $1.59g\;cm^{-3}$, respectively. These results showed that soil physical condition of Gyehwa reclaimed tidal land was very poor. Soil salinity ranged from 0.03 to 0.12%, and average of pH was 6.0, which implied that desalinization of Gyehwa reclaimed tidal land was progressed. However, soil nutrients in Gyehwa reclaimed tidal land were very unbalanced conditions as following, available phosphate $58mg\;kg^{-1}$, available silicate $85mg\;kg^{-1}$, cation exchangeable capacity $7.4cmolc\;kg^{-1}$ and organic matter $8.6g\;kg^{-1}$. On the farm household in Gyehwa reclaimed tidal land, fertilization amounts were $200-54-61(N-P_2O_5-K_2O)kg\;ha^{-1}$ They mainly practiced spring tillage(84%) rather than autumn tillage(16%), and only 14% of them applied rice straw annually in the paddy soil.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.315-320
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• 2015

Burcucumber (Sicyos angulatus) is an annual invasive plant species originated from North America. This species grows by twining around tree trunks, and blocks other plants from photosynthesis. Thus, it has caused the destruction of the ecosystem and biological diversity by threatening native plants. This study was performed to find out the effect of different soil water content (20%, 13%, 10%, 3%) and various shading degrees (0%, 60%, 80%) on the growth and photosynthesis-related activity of burcucumber. In the responses of burcucumber to soil water content, plant height (PH), leaf length (LL), leaf width (LW) and photosynthetic efficiency (PE) were lower at 20% water content than 10% reflecting that burcucumber plant grow well in the less dry soil and shows poor growth under wet soil condition. In shading experiment, PH, LL, LW and PE were lower at 80% than 60% shading and in general, the growth characteristics were lowered as the shading intensity increased. The improved growth of burcucumber under highly or moderately shaded condition implies that the plant can grow well without growth retardation and can be adapted to shading condition with other tall plant species including tree. Further study on the combination effects of above factors should be conducted in future for effective ecological control of burcucumber.