• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.7-12
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• 1977

This experiment was conducted in the laboratory in order to find out the relationships between the root growth and soil physical properties. The soils selected for this study were Sangju sandy loam, Yeongog loam, Hwadong silty clay loam, which have been considered to be a typical upland soils of Korea. Artificial core samples were made with various moisture contents and bulk densities. Elongation rate of pea seedling taproot and soil strength were measured respectively in these core samples. The results obtained are summarized as follows: 1. The soil strength increased with the bulk density and deceased with moisture content. 2. The correlation between root elongation and soil bulk density was significantly recognized at the same moisture content and the root elongation was influenced by the bulk density more significantly at dry condition. 3. The elongation rate of pea seedling taproot was significantly decreased by increasing the strength (Yamanaka tester and Fine probe) of the soils. 4. The soil strength of $21kg/cm^2$ in fine metal probe or 24mm in Yamanaka tester was considered to be the critical point for plant growth, which was restricting root elongation smaller than 1/4 of the maximum growth rate.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.553-563
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• 2019

In order to survey archaeological sites, drilling and excavation are carried out at the final stage. However, at the preliminary stage, non-excavation geophysical prospection is used for assessing underground archaeological ruins. Among the geophysical prospecting techniques, Ground Penetration Radar (GPR) prospection has effectively been applied to historical sites due to its high resolution at shallow depths. In this study, the GPR prospection was conducted to find underground ruins near Suseong-Dang, the place of ancient rituals in Buan area, Korea. First, the GPR prospection was conducted at three sites (Site-1, 2, and 3), and subsequently, the GPR prospection was carried out at Site-3 in more detail. As a result of the prospection, the underground layered structure of the survey area consists of three layers, which are soil layer, weathered rock, and sound rock from the surface. And the GPR anomaly to the archaeological structure was clearly identified at around 100-cm depth showing est-west direction that is parallel to the long-axis array. This GPR anomaly of irregular geomorphological features and intermittent distribution may be related to the ritual remains found in Suseong Dang. The GPR prospection could be effectively used to detect archaeological sites or remains buried in the ground.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6C
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• pp.339-347
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• 2008

The penetration of the probe produces the excess pore pressure due to the disturbance. The objective of this study is to evaluate the disturbance zone by using the dissipation of the excess pore water pressure, which was generated due to the penetration of the penetrometer with different size. The CPT, DMT and FVP (Field Velocity Probe) are adopted for in-situ tests. The tests are carried out in the construction site of north container pier of Busan new port, Korea where is accelerating the consolidation settlement using plastic board drains (PBD) and surcharges by crushed gravels. The coefficient of consolidation $(C_h)$ and soil properties are deduced by the laboratory test. The in-site tests are performed after the predrilling the surcharge zone at the point of 90% degree of consolidation. To minimize the penetration effect, the horizontal distance between penetration tests is 3m, the change of the pore pressure is monitored at the fixed depth of 24m. The coefficient of consolidation $(C_h)$ and the $t_{50}s$ are calculated based on the laboratory test and the in-situ data, respectively. The equvalent radi based on the $t_{50}$ shows that the FVP and the DMT produce the smallest and the greatest equivalent radi, respectively.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.16-23
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• 2011

BACKGROUND: This study was conducted to investigate the effects of different organic treatments and a chemical fertilizer on the soil chemical, physical, and microbial properties in an organic pear orchard. METHODS AND RESULTS: Control was referred as a NPK chemical fertilizer (15N-9P-10K) and organic treatments included compost containing with oil cake, compost containing with humic acid, and compost containing with chitin substance. All treatments applied at rates equivalent to 200 g N per tree per year under the tree canopy in March 30 of 2008 and 2009. Soil bulk density, solid phase, liquid phase, and penetration resistance were not significantly different among the treatments. Organic treatment plots had greater organic matter, total nitrogen, potassium, and magnesium concentrations compared to control, and the nutrient concentrations were not consistently affected by the organic treatments. Microbial biomass nitrogen and carbon, dehydrogenase, acid-phosphatase, and chitinase activities overall increased from March to August. Organic treatments, especially compost containing with oil cake or chitin aicd, increased the microbial variables compared to control. CONCLUSION(s): All the organic treatments consistently stimulated soil biological activity. The consistent treatment effect, however, did not occur on the soil mineral nutrition as the trees actively taken up the nutrients during a growing season, which would have diminished treatment effects. Long-term study required for evaluating soil physical properties in a pear orchard.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.241-248
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• 1993

An experiment was conducted in 1990~1991 to study the effects of various soil amelioration on the soil productivity and machine workability at tidal land paddy field of Kyewhado Substation, Homam Crop Experiment Station. The soil, Munpo Series(fine sandy loam, Typic Fluvaquents) was treated with gipsum, rice straw, rice straw compost and foreign soil(at 20cm depth) after deep ploughing. The results are surmerized as follows. 1. Sand and clay were slightly increased, while silt was slightly decreased in the rice straw and compost plots. The soil texture was changed from loam to sand loam by the addition of foreign soil 2. Soil bulk density and porosity was decreased in the rice straw, compost and foreign soil addition plots. 3. Cone penetration resistance was $12.5kg/cm^2$ at 10cm of soil depth before experiment and $12.5kg/cm^2$ at 20cm of soil depth after experiment except control, and the root zone was expended down to 20cm. 4. Soil salt content before experiment was 0.46 and 0.48% for surface soil(10cm) and subsoil(20cm), respectively ; The salt content of ameliorated plot was 0.26~0.32% and 0.16~0.31%, respectively, indicating good leaching of soil salt by the soil improvements. 5. The yields of rice in different treatments were in the order of the foreign soil addition > compost > gypsum > rice straw > control.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.189-197
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• 2002

The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the incremental filling ratio, IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity. In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR can be estimated from the plug length ratio PLR, which is defined as the ratio of soil plug length to pile penetration depth. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new design equations for calculating base load capacity and shaft load capacity of open-ended piles are proposed.

• Asian Journal of Turfgrass Science
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• v.17 no.2_3
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• pp.87-97
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• 2003

The growth characteristics of creeping bentgrass seeded in the seaside landfill golf course are as follows. 1. As a result of analysis on the chemical characteristics of soil mixture used for turfgrass ground in this experiment, soil pH was 7.9, which is somewhat higher than the creeping bentgrass reference value of pH 5.5∼6.5; T-N(%) was 0.02, which is proper for the reference value, and trace element too lacked. 2. The cultivar with the fastest water infiltration was Seaside II recorded as 226.2cm/sec, while that with the slowest water infiltration was Pennlinks recorded as 141.1 cm/hr which was too faster than the USGA water infiltration reference value of 15∼30cm/hr. For the surface hardness of turfgrass ground with different cultivars, no statistically significant variation was found between the Penncross grass and the Pennlinks recorded as 18.6mm and 19.1 mm, respectively. The soil penetration was the highest in Pennlinks recorded as 7.6kg/$\textrm{cm}^2$ and lowest in Penn A-1 as 6.1kg/$\textrm{cm}^2$. 3. As a result of evaluation on visual quality at the early stage of growth, Penncross showed the most excellent visual quality compared to the others. However, Penn A-1 showed the most excellent visual quality at a late stage of growth around Sep. 17, 2003, and it was also excellent in the evaluation of visual color. Seaside II showed higher density around the root and the longest root length and was highly resistant to salt compared to others, but the initial sprouting rate was not satisfied, and the visual quality in the summer season was inferior to others. 4. As a result of measurement of the traffic injury, Penncross showed the most tolerant to the traffic stress and Pennlinks showed the most susceptible.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.730-739
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• 2010

Stress history increases in penetration resistance due to the increase in residual horizontal stress of granular soil. This study analyzes the effect of stress history on the results of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance with regard to vertical effective stress is a little affected by stress history. The horizontal stress index($K_D$) in DMT more reflects the influence of stress history on granular soil than the dilatometer modulus($E_D$) and cone resistance($q_c$). The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress($E_D/{\sigma_m}'$) is unique correlated with the state parameter, regardless of stress history.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.151-161
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• 2003

In this study, an interpretation method is proposed to evaluate the stress conditions, including individual excess pore pressure components ($\Delta{u}_{oct}$/ and $\Delta{u}_{shear}$), of normally consolidated clay elements adjacent to the cone face. It is assumed that the stress path of triaxial compression is representative f3r that of the soil element and the soil is elastic-perfectly plastic material. The proposed method is applied to the results of miniature piezocone tests conducted at Louisiana State University calibration chamber system. Based on the results of interpretation, it was found that the ratio of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ estimated by the proposed method is affected only by the pore pressure parameter. The proposed method gives consistent and reliable values of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ compared with early works, whereas those obtained by other solutions are significantly dependent on the accuracy in estimating soil properties such as undrained shear strength and rigidity index.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.4
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• pp.524-535
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• 1994

The interaction and detergency between oily soil and surfactant solution were studied Samples used were tristearin, tripalmitin and their mixture as a triglyceride, myristic acid as a fatty acid and sodium dodecyl sulfate (SDS) as surfactant. The results were as follows: 1. The mixtures of model oily soils were formed of eutectic point and their melting point were lower than them of individual oily soils. 2. The formation of liquid crystalline (LC) phase was recognized in the triangle phase diagram for SDS~ water~model oily soil system. The areas of LC phase region were in the order of SHS~ water~myristir acid> SDS~ water~mixture of tristearin, tripalmitin and myristic acid (TS/TP/M)>SDS~water~mixture of tristearin and tripalmitin (TS/TP) 3. The LC phase region expanded to wide concentration range of SDS solution and high concentration range of model oily soil with increasing temperature. Particularity, the LC phase region expanded highly at $30~40^{\circ}C$ but when the temperature was elevated above $40^{\circ}C$, expanding tendency decreased. 4. In the system of myristic acid and TS/TP/M contacted with SDS solution, the LC phase was already formed at $28^{\circ}C$ and the region of the LC phase were expanded with increasing temperature. But in the system of TS/TP contacted with SDS solution, the LC phase was not formed in whole experiment temperature. 5. The detergency of myristic acid was very high ann it was recognized that the formation of the LC phase played an important role in the detergency. The detergency of TS/TP was very for low, but when TS/TF was mixed with myristic acid, the detergency of TS/TP increased. It is supposed that the LC phase was formed butween SDS solution and myristic acid promoted to penetration of SDS solution into the inner parts of TS/TP.