• KIEAE Journal
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• v.10 no.3
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• pp.11-16
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• 2010

This paper has attempted to investigate the change in soil moisture volume and temperature of architecture by planting ground(soil thickness and soil mixture ratio) and ground cover plants(Sedum sarmentosum, Zoysia japonica, Chrysanthemum zawadskii) for middle region green roof system. For this, a test was conducted on the roof of Konkuk University building from April 2009 to October 2009. In terms of treatment, five types(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) depending on soil mixture ratio and two types(15cm, 25cm) by soil depth were created. Results of soil moisture volume by soil mixture ratio in the 15cm soil thickness showed that the difference was significance between simple soil and mixture soil treatment, however, the statistical significance was not recognized according to soil mixture ratio. In case of 25cm soil thickness, soil moisture volume by soil mixture ratio was more higher 7Vol.%~10Vol.% in the mixture soil than simple soil treatment. In terms of districts planted ground cover plants, soil volume moisture differed among plants in the order Zoysia japonica 17.74 Vol.%$34.86^{\circ}C$, district non-planted $27.49^{\circ}C$, Sedum sarmentosum $25.11^{\circ}C$, Chrysanthemum zawadskii $23.08^{\circ}C$, Zoysia japonica $24.45^{\circ}C$ respectively So, concrete surface showed more higher $5^{\circ}C{\sim}15^{\circ}C$ than other things among the all the time. Result of inner temperature of the architecture and soil, it was measured inner of architecture $25.69^{\circ}C$, inner district non-planted $24.29^{\circ}C$, Chrysanthemum zawadskii $23.90^{\circ}C$, Zoysia japonica $24.02^{\circ}C$, Sedum sarmentosum $25.13^{\circ}C$, respectively.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.1-9
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• 2011

Storing and transferring heat in soils is governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the evaluation results of the ground subsurface temperature and apparent thermal diffusivity of soils by using ground temperature data collected at the depths of 0.5 m, 1.0 m, 1.5 m, 3.0 m, and 5.0 m at four sites. The existing correlation assuming that the soil was homogeneous and of constant thermal diffusivity was applied to calculate the subsurface temperature and two analytical equations, amplitude and phase equation, were also used to evaluate the soil apparent thermal diffusivity. Comparison of the estimated and of the measured values of the subsurface temperature has shown that the empirical correlation predicts quite accurately the ground temperature at various depths. Based on the one-dimensional heat conduction equation, the apparent thermal diffusivity can be estimated by the two equations.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.36-46
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• 2009

The objective of this study is to analyze the effect of artificial soil ground on a structure. When the artificial soil ground is planted, the technical factors to be considered will be the load for buildings and the growth of plants. There are no current studies of the effect of artificial soil ground on a structure and this study will analyze the load effects of artificial soil ground, which mixes both pearlite and natural soil on structures. The load affecting the structures due to artificial soil ground will be maximized when the artificial soil ground becomes saturated, and which would occur when the rainfall intensity exceeds the infiltration capacity of the artificial soil ground. In order to determine whether the artificial soil ground has reached saturation or not, a 10 years frequency and 10 minutes rainfall intensity which is used for in urban drain design, is utilized. The hydraulic conductivity of artificial soil and mixed soil has been changed depending on the proportion of the mix, It has a range of fluctuation in the degree of hardening, in particular, but does not exceed the 10 minutes rainfall intensity over 10 years frequency in the most cases. Therefore, it would be efficient to apply the saturated unit weight of artificial soil ground as the design load of a structure.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.553-560
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• 2002

The improvement effect of soft ground is estimated by unconfined strength mainly. The unconfined strength of solidification agent treated soil is likely to vary with ununiformed mixing ratio and water content change of in-situ ground place by place. So, it is unreasonable to apply a solidification agent mixing ratio obtained from laboratory test results on all over the soft ground. In this study, it was analysed how the unconfined strength would be effected by the water content of soft ground. For this study, a series of unconfined compressive tests are peformed on various water content soil samples. The test results showed that the strength was fallen to 30∼80% by two times increase of water content approximately, This means that strength of solidification agent treated soil is influenced greatly by water content of raw soft ground and mixing ratio of solidification agent. It was suggested that the method how to decide the mixing ratio with soft ground water content.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.211-215
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• 2008

This paper deals with the transient ground impedance of small-sized needle-rod installed in a test field, Impulse voltage generator was used to inject lightning impulse on a ground electrode and modified fall-of potential method was proposed to measure the high ground potential rise. Transient ground impedance was analysed with impedance curve and I-V curve as respects the resistivity of soil. Soil ionization near the ground electrode is activated in high resistivity soil and have an effect on the reduction of transient ground impedance significantly.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.89-95
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• 2010

There is the freezing method as one of the ground improvement methods for excavating an underground tunnel, and due to its improved reliability, recently construction cases of applying this method into sandy soil grounds as well as cohesive soil grounds of cities have been reported. But, applying the freezing method into cohesive soil grounds could bring concerns of the expansion of the whole ground and the settlements from thawing of ground. In this study, the deformation strength characteristics of cohesive soil which received freezing and thawing hysteresis were examined using the sample collected from the site of cohesive soil ground applied with the freezing method and its structural characteristics were analyzed using an electronic microscope. And, the test with cohesive soil reconstituted from cohesive soil which received freezing and thawing hysteresis was carried out and its result was analyzed comparatively. The result of this test showed that the structure of natural clay was significantly changed due to freezing and thawing hysteresis.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.116-119
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• 2000

There has been a steady increase in geoenvironmental engineering projects where geotechnical engineering has been combined with environmental concerns. Many of these projects involve some investigation on contaminant and leachate flume in the ground and landfill. In this study, investigation and assesment on soil and groundwater around the waste landfill was carried out. Many techniques such as drilling and sampling method were applied. As a result of this study, the concentration of soil and groundwater were investigated and analysed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.78-84
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• 2009

This paper presents measurement results of transient impedance for small-sized ground electrodes in a discharge region of soil. For a realistic analysis of ionization characteristics near the ground electrode, three types of ground rod installed outdoors and high voltage impulse generator were used for injecting test current. From the analysis of response voltage and current flowing ground electrode to earth, it is verified that the ionization near the ground electrode contributes to reduction of ground impedance and limits the ground potential rise effectively in high resistivity soil. As a threshold electric field density for ionization is small in low resistivity soil, the shape of ground electrode rarely contributes to the transient impedance. And, from the experiment result with shape of ground electrode, the rod with needles is more effective to reduce the transient impedance than the plate electrode in the voltage range including with ionization regions of soil.

• Analytical Science and Technology
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• v.16 no.1
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• pp.59-69
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• 2003

Benzophenone (BZP) and 4-nitrotoluene (4-NT) listed as endocrine disrupting chemicals are suspected to contaminate ground water sites and soil. Analytical method for simultaneous determination of the two chemicals in soil and ground water was developed by gas chromatography-mass spectrometry. Water (100 ml) was extracted with hexane, and soil (10 g) was extracted with methanol and hexane. Recovery in water was >72% for BZP and 90-118% for 4-NT. Recovery for 4-NT and BZP in soil was 51-59% with coefficient variation of less than 19.5%. Calibration curves showed a good linearity with $r^2=0.997$. In water and soil collected at nation-wide sites, BZP was found at 5 sites among 43 water sites at the concentration of $14.87{\pm}3.83ng/100 ml$. No 4-NT was found. It is suggested that this method is appropriate to the simultaneous quantitation of 4-NT and BZP in ground water and soil samples.

• Land and Housing Review
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• v.2 no.2
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• pp.145-155
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• 2011

It is very important for successful construction to estimate the soil volume conversion factor of domestic weathered ground accurately and reasonably. However, it is very difficult to quantify the weathering degree of weathered ground at the field, so that the soil volume conversion factor used in Korea is often dependent upon the standard of foreign countries. Besides, the soil volume conversion factor of domestic weathered ground has been rarely studied and the use and accuracy of the soil volume conversion factor have been questioned persistingly. This study suggests a simple but robust method for estimating the soil volume conversion factor and measuring the weathering degree reasonably, and attempts to establish the utilization of a soil volume conversion factor measurement system based on experimental and analytical results. We made relationship between electrical resistivity and weathering degree presented from weathering index obtained through laboratory tests using field samples, and an estimation method of in-situ weathering degree for granites and a calculation method of soil volume conversion factor using electrical resistivity. And also, we suggested the photogrametry measurement-equipment system for measuring the volume of cargo box and the application plan of stand equipment and RFID for calculating the earth volume and distinguishing buggies in order to design the measurement system for soil volume conversion factor applicable to the field. Ultimately, the Weathered Earth-work Management Program (WEMP) was developed, so field managers may easily obtain the information about earth volume and soil volume conversion factor at the weathered ground.