• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.824-830
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• 2006

Several tests were conducted to optimize the design parameters of ln-situ soil flushing processes for diesel contaminated soil. According to the batch extraction test for three anionic surfactants evaluation, Calgonit limiting bubble occurrence was selected for its higher oil cleaning efficiency. After optimum surfactant selection, there were many sets of column flushing test. Over 70% of BTEX was removed in this surfactant dose with 400% of soil volume. In the case of no surfactant addition flushing in column, so called "blank flushing test", BTEX removal rate was 64%. But when we reused the effluent for the cleaning solution, the removal rate was decreased to 46.9%. This result showed reabsorption of oil occurred on the soil. With the addition of Calgonit solution to the diesel contaminated column, BTEX was removed up to 98.9% during the first flushing and 99.4% for the second recirculation flushing. In microcosm tests, diesel contaminated soils were cleaned by both surfactant flushing and biological activities. In anoxic condition, nitrate was used as an electron acceptor while the surfactant and the oil were used an electron donor. BTEX removal efficiency could be achieved up to 80% by biological degradation.

• Tunnel and Underground Space
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• v.23 no.6
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• pp.457-469
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• 2013

We have analyzed the regional in-situ stress pattern using 460 stress measurement data at about 100 test sites in Korea, and suggested correlation equations of stress-depth and stress ratio-depth. We made Korea Stress Map(KSM) as in-situ stress fields of the Korean peninsula, combining with a paleo-stress analysis according to the geological period and a stress estimation from focal mechanism. We confirmed the reliability and applicability of correlation equations derived in this study, comparing with worldwide stress-depth patterns, and also estimated the pattern of in-situ stress fields of north-eastern Asia including Korea, China and Japan, comparing with World Stress Map.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.25-31
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• 2004

Rail road slope can be fatted because of existence of unexpected soft subsoil. Purpose of this study is verifying the cause of rail road slope failure and determination of soil strength for remedy. Drilling some boreholes, cone penetration test and field vane test were executed in order to find out the cause of slope failure. In addition, laboratory test was conducted in order to determine soil strength of soft soil sampled as undisturbed state. As a result of both the in-situ and the laboratory tests, the cause of slope failure is thought to be propagation of failure zone by progressive rupture of overconsolidated clay Soft soil strength was determined through back analysis of the failed slope.

• Structural Monitoring and Maintenance
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• v.7 no.4
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• pp.319-344
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• 2020

Inverse analysis of non-linear reinforced concrete bridge pier using recursive Gaussian filtering for in-situ condition assessment is the main theme of this work. For this purpose, minimum variance unbiased estimation using unscented sigma points is adopted here. The uniqueness of this inverse analysis lies in its approach for strain based updating of engineering demand parameters, where appropriate bound and constrained conditions are introduced to ensure numerical stability and convergence. In this analysis, seismic input is also identified, which is an added advantage for the structures having no dedicated sensors for earthquake measurement. First, the proposed strategy is tested with a simulated example whose hysteretic properties are obtained from the slow-cyclic test of a frame to investigate its efficiency and accuracy. Finally, the experimental test data of a full-scale bridge pier is used to study its in-situ condition in terms of Park & Ang damage index. Overall the study shows the ability of the augmented minimum variance unbiased estimation based recursive time-marching algorithm for non-linear system identification with the aim to estimate the engineering damage parameters that are the fundamental information necessary for any future decision making for retrofitting/rehabilitation.

• Geomechanics and Engineering
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• v.34 no.2
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• pp.139-154
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• 2023

Red-bed soft rock is a common stratum and it is necessary to evaluate the mechanical properties and bearing capacity of red-bed soft rock mass affected by different environmental effects. This paper presents a complete procedure for evaluating the bearing capacity of red-bed soft rock by means of geophysical exploration and in-situ rock mechanics tests. Firstly, the thickness of surface loosened rock mass of red-bed soft rock was determined using geophysical prospecting method. Then, three environmental effects, including natural weathering effect, dry-wet cycling effect and concrete sealing effect, were considered. After each effect lasted for three months, in-situ rock mass mechanical tests were conducted. The test results show that the mechanical properties of rock mass considering the sealing effect of concrete were maintained. After considering the natural weathering effect, the mechanical parameters decrease to a certain extent. After considering the effect of dry-wet cycling, the decreases of mechanical parameters are the most significant. The test results confirm that the red-bed soft rock dam foundation rock mass will be significantly affected by various environmental effects. Therefore, combined with the mechanical test results, some useful implementations are proposed for the construction of a red-bed soft rock dam foundation.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.476-481
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• 2009

Bi-directional load test is one of O-cell tests. The O-cell test is a system which may be used for performing static load tests on cast in situ reinforced concrete bored piles. The technique was devised and developed by Osterberg of Northwestern University(USA) and has been in use around the world. The principle of the method is that an O-cell is installed in a cast in situ bored pile base. Once the pile concrete reaches its design strength the cell is connected to an hydraulic pump and pressured. Pressurization causes the cell to expand, developing an upward force on the section of pile above the cell loads, pile movements and strains within the pile then enable the capacity of the pile and its load settlement curves to be ascertained. The O-cell pile load test with variable end plate is operated on second steps - the first step is to confirming end bearing capacity with variable end plate and the second step is similar to the conventional O-cell test. In the study, To calculate ultimate capacity of bi-directional load test using model with the pile with variable end plate O-cell.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.152-160
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• 2009

The pipe jacking method which is a non-excavation method is frequently used due to constructability and economical efficiency in a medium or small-sized pipeline construction. However, jacking process of the method still causes problems that the base ground is disturbed and loosen. These lead to surface settlement, strength decrease and leakage of water. Therefore, this study presents in-situ application of the steel pipe jacking with grouting, and it is that jacking and grouting are progressed simultaneously. To verify this, the steel pipe jacking with grouting and the existing steel pipe jacking have been constructed on the same ground condition. It has been proved that the steel pipe jacking with grouting is in-situ applicable according to results of monitoring surface settlement, in-situ density, GPR geophysical prospecting and large scale direct shear test.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.140-144
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• 2014

Purpose: The recent surge in breast carcinoma patients is reported in a variety of statistics. Breast cancer occurs mainly from duct and lobulus: 85% is from the breast ducts. The present study is aimed to distinguish the difference in $SUV_{max}$ changing over time by identifying the type of cancers attacking from the duct. Materials and Methods: The subjects of the study are 291 female breast cancer patients who have visited the present PET/CT center from July 1, 2012 to July 23, 2013. Based on the pathological results, 248 IDC (invasive ductal carcinoma) patients and 43 DCIS (ductal carcinoma in situ) patients were selected. In the same manner as the general PET/CT scan (3.7 MBq/Kg), F-FDG was injected, followed by the primary test (Routine tests) after 1 hr, and the secondary test (Delay test) after another hr. $SUV_{max}$ was measured after setting ROI in the lesion based on the data from the two tests. Results: As the comparative result of the change in the lesion $SUV_{max}$ between the two groups, IDC group's $SUV_{max}$ showed M=7.11 and SD=5.405 in the primary test and increased M=7.11 and SD=5.405 in the secondary test (P<0.05); DCIS group's $SUV_{max}$ showed M=2.739, SD=1.229 in the primary test and increased M=2.614, SD=1.470 in the secondary test (P<0.05). Conclusion: As the comparative result of $SUV_{max}$ over time between the groups, IDC showed increased $SUV_{max}$ in the secondary test (Delay test) compared to the primary test (Routine test) (P=0.000); DCIS showed decreased $SUV_{max}$ in the secondary test (Delay test) compared to the primary test (Routine test) (P=0.039). It was confirmed through this study that the change in $SUV_{max}$ has occurred over time by the type of breast cancer (IDC or DCIS) occurring from the breast ducts. However, the onset of breast cancers (ILC, LCIS) from the lobulus was not discussed due to the lack of samples. Future research on the breast cancers from the lobulus is suggested.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.61-72
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• 1996

A series of batch and lab-scale continuous tests were conducted to optimize the design parameters for the full-scale in-situ soil flushing experiments. The cleaning abilities of the surfactant solutions of Tween 80, Triton X-100 and SDS were compared for the soil artificially contaminated by hydrophobic organic contaminants: n-dodecane, naphthalene and anthracene. Tween 80 and Triton X-100 were shown to be efficient for n-dodecane. SDS and Tween 80 were shown to be efficient for naphthalene and anthracene. At the end of each column test, the sorbed amount of surfactant to soil was also measured. Tween 80 was found to be the least adsorbed surfactant to soil. The flushing ability at flowrate of 7 ml/min, was hampered comparing to flowrate of 3 and 5 ml/min. Initial pH of the soil did not significantly affect the flushing efficiencies. Tween 80 was determined as the most harmless surfactant for the Gram(+) and Gram(-) bacteria.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.297-308
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• 2007

The granulation equipment of concentrated wastes is manufactured for the polymer solidification of concentrated wastes. It uses liquid sodium silicate as a granulating agent for the granulating of dried powder containing boric acid. The granulating agent is sprayed in the form of droplet and mean size of dried granules is $2{\sim}4mm$. The new technology which has been used for the polymer solidification of spent resin in U.S. and certified by Nuclear Regulatory Commission (NRC) is successfully applied to concentrated wastes. This uses in-situ solidification process within drum without mechanical mixing. Maximum loading of waste can be achieved without increasing of waste volume. Polymer waste forms were evaluated with several test such as fire test, compressive strength test, leaching test, immersion test, irradiation test, and thermal cycling test according to standard test procedures.