• Journal of Industrial Technology
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• v.12
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• pp.15-23
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• 1992

This research is to investigate the effect of base roughness of footing on characteristics of load-settlement curve. Parametric experiments of small scaled model test were performed with changing the properties of base roughness of model footing; Gluing the vinyl, aluminum, sand paper, sand beneath the model footing surface. The width of model footing and relative density of soil foundation were also changed to investigate their effects on settlement characteristics of footing. The ultimate bearing capacity as well as the initial slope of load-settlement curve obtained from test results were compared with those from limit equilibrium methods proposed by Terzaghi, Hansen and Meyerhof. From test results, it was confirmed that the base roughness affected the failure mechanisms of showing different shapes of slip lines formed beneath the footing.

• Journal of Industrial Technology
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• v.18
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• pp.7-16
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• 1998

This paper is an experimental study of investigating the reinforcing effect and the behavior of cohesionless slope installed with reticulated root pils. Reduced scale model tests with plane strain conditions were performed to study the behavior of the strip footing located on the surface of cohesionless slopes reinforced with root piles. Model tests were carried out with Jumunjin Standard Sand of 45% relative density prepared by raining method to have an uniform slope foundation during tests. Slope of model foundation was 1 : 1.5 and a rigid model slop. Parametric model tests were performed with changing location of model footing, arrangements of root piles and angles of pile installation. On the other hands, the technique with camera shooting was used to monitor sliding surface formed with discontinuty of dyed sand prepared during formation o foudation. From test results, parameters affecting the behavior of model footing were analyzed qualitatively to evaluate their effects on the characteristic of load - settlement, ultimate bearing capacity of model footing and failure mechanism based on the formation of failure surface.

• Journal of the Korean Geotechnical Society
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• v.29 no.4
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• pp.23-32
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• 2013

In order to evaluate the bearing capacity behaviour of a monopod suction bucket foundation for an offshore wind tower at the western sea of Korea, a centrifuge load test and numerical analyses were performed. The monopod bucket foundation was designed to be installed in a silty sand layer. The model soil was prepared to simulate a target site by using soil samples having similar properties and controlling relative density. In-flight miniature cone penetration test and bender element array were used to confirm that the model soil had represented the target site conditions. The load - rotation curve of the centrifuge load test was analysed. A series of numerical analyses were performed to validate the experimental conditions. Self-weight of the model, distance to the boundary and elastic modulus of the soil layer were varied to study their effects on the load - rotation curves.

• Journal of the Korean GEO-environmental Society
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• v.18 no.6
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• pp.39-44
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• 2017

The behavior of the lateral resistance beyond the yield condition on single pile has been evaluated by comparative analysis. Pushover analysis of single pile has been performed to compare to the results on lateral load test of the pile foundation. The study for the behavior beyond the yield condition on single pile had been performed on the results on the lateral load test and pushover analysis considering mechanical conditions of the ground soil and the pile foundation.

• Steel and Composite Structures
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• v.25 no.2
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• pp.231-244
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• 2017

This paper presents the structural identification of an arch dam model for the damaged, repaired and strengthened conditions under different water levels. For this aim, an arch dam-reservoir-foundation model has been constructed. Ambient vibration tests have been performed on the damaged, repaired and strengthened dam models for the empty reservoir (0 cm), 10 cm, 20 cm, 30 cm, 40 cm, 50 cm and full reservoir (60 cm) water levels to illustrate the effects of water levels on the dynamics characteristics. Enhanced Frequency Domain Decomposition Method in the frequency domain has been used to extract the dynamic characteristics. The dynamic characteristics obtained from the damaged, repaired and strengthened dam models show that the natural frequencies and damping ratios are considerably affected from the varying water level. The maximum differences between the frequencies for the empty and full reservoir are obtained as 16%, 33%, and 25% for damaged, repaired and strengthened model respectively. Mode shapes obtained from the all models are not affected by the increasing water level. Also, after the repairing and strengthening implementations, the natural frequencies of the arch dam model increase significantly. After strengthening, between 46-92% and 43-62% recovery in the frequencies are calculated for empty and full reservoir respectively. Apparently, after strengthening implementation, the mode shapes obtained are more acceptable and distinctive compared to those for the damaged model.

• Journal of the Korean GEO-environmental Society
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• v.14 no.7
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• pp.13-18
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• 2013

As a new foundation treatment technology, long-short pile composite's design theory is still in primary phase, and there are no explicit settlement calculation methods in active codes. So it is necessary to study the working mechanism and the methods of settlement calculation. In this paper, the mechanics of long-short pile composite foundation are fully discussed. Meanwhile, based on the shear deformation method, the Mylonakis & Gazetas models about mutual action between two piles and the one between pile and soil are introduced, Considering the performance of cushion, the flexible factors of mutual actions are provided. Then the settlement calculation of long-short pile composite foundation which can consider the mutual actions between pile, soil and cap is deduced, and the correlated program is also developed. Finally, an engineering example is discussed with the method. A comparison shows that calculated results and measured data from a field test pile are in a good agreement, indicating that the presented approach is feasible and applicable in engineering practice.

• Journal of Korean Society for Quality Management
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• v.52 no.1
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• pp.135-148
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• 2024

Purpose: This study is to investigate the literature on accelerated tests based on the acceleration model and to provide a compilation of results on the parameters applied in the acceleration model and the test conditions. Methods: This research is conducts a literature review on accelerated tests using the acceleration model, with a focus on test targets, test conditions, and parameter values. The study is organizing the results of this literature review to facilitate their application in the design of reliability tests. Results: A literature review investigated a variety of test targets, test conditions, and parameter values. Conclusion: The results of the literature research conducted revealed various acceleration model parameter. Such literature research on accelerated tests can establish the foundation for reliability test design and contribute to future product development and quality improvement

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.3
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• pp.97-106
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• 2000

The study is closely relevant to Lade's single work hardening model. This model has been shown to have good applicability to cohesive soils. However the validation of this model on the clayey soils has not been satisfactorily reported. To scrutinize the applicability of this model on clayey foundation the laboratory tests for Kwangyang clayey soils were performed using the improved cubical triaxial test apparatus designed originally by Lade. A computer program was developed by which soil parameters for the single work-hardening model can be rationally determined by deleting some dispersed test data generated usually at the initial stage of laboratory tests. And using the program numerical analysis of the cubical clayey specimens using intermediate principal stress was carried out and a good agreement between observed values and numerical results was found.

• Journal of the Korean Geotechnical Society
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• v.22 no.4
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• pp.95-104
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• 2006

For the interests in the economical and safe design of foundation system, the concern on the piled raft or disconnected piled raft foundation system is increasing now. In this study, the behavior and the effects of the disconnected piled raft foundation not studied actively in this country were examined using the triaxial compression tests in place of laboratory model tests. The triaxial test samples were prepared with Jumunjin standard sand and the carbon rods, which simulate the ground soil and piles respectively. After the sample in which carbon rods were arranged was laid inside the triaxial chamber, the confining pressure was applied and then loading test was conducted. To analyze the reinforcing effects of the disconnected piled raft foundation, a few number of tests were carried out by changing the number, the diameter and the length of the model piles. As a result of this study, in the disconnected piled raft foundation system, even though the number of pile is few and the diameter of pile is small, the settlement of the foundation system decreased greatly.

• Geotechnical Engineering
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• v.10 no.3
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• pp.5-16
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• 1994

This paper presents a new method to improve the bearing capacity of a square shallow foundation placed on a sand layer reinforced with geogrids which shows promise for further field work. The geogrid reinforcement will be necessary in the case of machine foundation, embankments for railroads, and foundations of structures in earthquake-prone areas. The ultimate bearing capacity (UBC) for the unreinforced sand and reinforced sand has been compared. Also, the effect of length, spacing, width of reinforcement on increasing the UBC have been evaluated. Based on the present model test results, it appears that significant improvement in the UBC of medium sand can be achieved by geogrid reinforcement.