• Journal of the Korean GEO-environmental Society
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• v.18 no.9
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• pp.11-18
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• 2017

Numerical analysis method for prediction of pile behaviour characteristics has widely been used in detail design process before construction because field static loading test requires high cost. However, the reliability verification of numerical analysis of result is not permitted compare with field test. In this study, to verify the numerical analysis results, pile behaviour prediction was compared with field static loading test results. For exact analysis of interaction between pile and ground, soil investigation and in-situ test such as boring, SPT and bore-hole shear test were performed before pile static loading test. During the static loading test, pile behaviour characteristics were analyzed under every loading condition. After static pile loading test, numerical analysis was carried out under same condition with static pile loading test. In the numerical analysis, to apply same loading condition with each loading condition in the field test and to compare with between the results of numerical analysis, the field test results for reliability were verified with the results of numerical analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.53-60
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• 2019

In this study, a method for updating the finite element model of bridges with genetic algorithm using static displacement were presented, and verified this method using field test data for PSC girder bridge. As a field test, static load test and pseudo-static load test were conducted, and updated the finite element model of test bridge using each test data. Finally, evaluated the bridge load carrying capacity with updated model using pseudo-static load test's displacement data. To evaluate the bridge load carrying capacity, KHBDC-LSD, KHBDC and AASHTO LRFD's live load model were used, and compared the each results.

• Geomechanics and Engineering
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• v.11 no.5
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• pp.625-638
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• 2016

This paper presents field study and numerical modeling results for a single-cell low-fill concrete box culvert under a flexible pavement subjected to traffic loading. The culvert in the field test was instrumented with displacement transducers to capture the deformations resulting from different combinations of static and traffic loads. A low-boy truck with a known axle configuration and loads was used to apply seven static load combinations and traffic loads at different speeds. Deflections under the culvert roof were measured during loading. Soil and pavement samples were obtained by drilling operation on the test site. The properties of the soil and pavement layers were determined in the laboratory. A 3-D numerical model of the culvert was developed using a finite difference program FLAC3D. Linear elastic models were used for the pavement layers and soil. The numerical results with the material properties determined in the laboratory were compared with the field test results. The observed deflections in the field test were generally smaller under moving loads than static loads. The maximum deflections measured during the static and traffic loads were 0.6 mm and 0.41 mm respectively. The deflections computed by the numerical method were in good agreement with those observed in the field test. The deflection profiles obtained from the field test and the numerical simulation suggest that the traffic load acted more like a concentrated load distributed over a limited area on the culvert. Elastic models for culverts, pavement layers, and surrounding soil are appropriate for numerical modeling of box culverts under loading for load rating purposes.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.373-380
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• 2002

In this study, In order to compare the behavior of axail load transfer for S.L. coated piles and uncoated piles installed at a field test site. During static pile load tests, axial load transfer for S.L. coated piles and uncoated piles were measured.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.333-340
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• 2003

In Korea, drilled shaft are generally socketed into rock. Driven pile has environmental problems such as vibration and noise. Therefore, applications of the drilled shaft are increasing in Korea. In this paper, static load test data of the rock socketed drilled shaft at Gwangandaero and Suyeong 3hogyo are analyzed. The bearing capacities from field test data and theoretical formula are compared and analyzed. From this study, design approaches for drilled shafts in Korea are examined and several suggestions are proposed.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.59-69
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• 2019

Grout injection is mainly used for permeability reduction and/or improvement of the ground by injecting grout material into pores, cracks, and joints in the ground. The oscillatory grout injection method was developed to enhance the grout penetration. In order to verify the level of enhancement of the grout, field grout injection tests, both static and oscillatory tests, were performed at three job sites. The enhancement in the permeability reduction and ground improvement effect was verified by performing a core boring, borehole image processing analysis, phenolphthalein test, scanning electron microscopy analysis, variable heat test, Lugeon test, standard penetration test, and an elastic wave test. The oscillatory grout injection increased the joint filling rate by 80% more and decreased the permeability coefficient by 33-68%, more compared to the static grout injection method. The constrained modulus of the jointed rock mass was increased by 50% more with oscillatory grout injection compared to the static grout injection, indicating that the oscillatory injection was more effective in enhancing the stiffness of the rock mass.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.411-418
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• 2001

The last 30 years have been significant worldwide growth in the use of EPS as a lightweight fill material. This paper analyzes the compressible inclusion function of EPS which can results in reduction of static earth pressure by accomodating the movement of retained soil. A series of model tests was conducted to evaluate the reduction of static earth pressure using EPS inclusion and determine the optimum stiffness of EPS, Also, field test was conducted to evaluate the reduction of static earth pressure using EPS inclusion. Based on field test it is found that the magnitude of static earth pressure was reduced about 20% compared with theoretical active earth pressure.

• Structural Engineering and Mechanics
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• v.71 no.1
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• pp.13-22
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• 2019

In this paper, the static and dynamic responses of a tied-arch railway bridge under train load were studied through field tests. The deflection and stresses of the bridge were measured in different static loading scenarios. The dynamic load test of the bridge was carried out under the excitation of running train at different speeds. The dynamic properties of the bridge were investigated in terms of the free vibration characteristics, dynamic coefficients, accelerations, displacements and derailment coefficients. The results indicate that the tie of the measuring point has a significant effect on the vertical movement of the test section. The dynamic responses of arch bridge are insensitive to the number of trains. The derailment coefficients of locomotive and carriage increase with the train speed and symmetrically distributed double-line loads reduce the train derailment probability.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.635-648
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• 2020

Performance improvement of helical piles in static load tests using hexagon joints that do not require welding or bolting was investigated. Two sites were selected for pile field tests to evaluate their bearing capacity. Static and pull-out load tests were undertaken to assess the method for estimating bearing capacity. The field tests indicated that the bearing capacity of the gravity grout pile was ≥600 kN in the static load test, consistent with the AC 358 Code. The non-grout pile had a bearing capacity of ≤600 kN, suggesting that gravity grouting is required. Field pile load-test results were used to establish the bearing capacity equation, based on a small number of helical pile.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1730-1738
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• 2001

This paper presents an overview of testing and analyzing field performance of a centrifugal chiller which has a rated capacity of 200 RT(703 kW). Field data of a chiller installed in the cleanroom research building of KIST has been collected far performance analysis. The operating data included start-up, shut-down, and quasi-static state where cooling capacity and compressor power consumption varied cyclically. It was found that the steady-state thermodynamic model could be applied to relate the cooling capacity and COP under quasi-static conditions. The results led to finding the required cooling load pattern and a possible energy saving method. This study provides a method of evaluating performance of a large capacity centrifugal chiller in which field test is necessary.