• Geomechanics and Engineering
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• v.29 no.5
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• pp.487-496
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• 2022

Most of the pile's vertical static load tests in construction sites are the proof load tests, which is difficult to accurately estimate the ultimate bearing capacity and analyze the reliability of piles. Therefore, a reliability analysis method based on the proof load-settlement (Q-s) data is proposed in this study. In this proposed method, a simple ultimate limit state function based on the hyperbolic model is established, where the random variables of reliability analysis include the model factor of the ultimate bearing capacity and the fitting parameters of the hyperbolic model. The model factor M = R_uR / R_uP is calculated based on the available destructive Q-s data, where the real value of the ultimate bearing capacity (R_uR) is obtained by the complete destructive Q-s data; the predicted value of the ultimate bearing capacity (R_uP) is obtained by the proof Q-s data, a part of the available destructive Q-s data, that before the predetermined load determined by the pile test report. The results demonstrate that the proposed method can easy and effectively perform the reliability analysis based on the proof Q-s data.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1203-1208
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• 1996

Crack growth tests on silicon nitride have been made to clarify the crack growth characteristics under static and cyclic loading. Under constant K(K: stress intensity factor) static loading the crack growth rate in silicon nitride decreases with increasing crack extension and is finally arrested. The cack growth resistiance is largely reduced by the application of stress cycling and though the crack growth resistiacne increases with increasing of crack extension the increasing rate is much smaller under cyclic loading than under static loading.

• 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.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.69-75
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• 2017

Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.18-24
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• 2010

Because of the increasing demand on the high precision and high response of a machinery, electronic control valves are widely adopted at various application fields. This paper studies on the static characteristic of a first-stage proportional pressure control valve. At first an experimental apparatus including hyd. pump variable speed inverter, pressure and data aquisition system was setted up with the experimental apparatus, various tests such as P-Q-W test, hyd, pump, dynamic, static, frequency response test of the proportional valve was carride out and the results are discussed.

• Proceedings of the Korean Reliability Society Conference
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• 2006.05a
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• pp.357-361
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• 2006

Fatigue fracture behavior of a hybrid joint part with bolting was evaluated in comparison to the case of static fracture. Hybrid joint part specimens for bending test were made with layers of CFRP and aluminum honeycomb. Characteristic fracture behaviors of those specimens were obviously different under static and cyclic loads. Static bending load showed the shear deformation at the honeycomb core, whereas cyclic bending load caused the delamination between CFRP skin layers and honeycomb core. Experimental results obtained by static and fatigue tests were considered in modifications of design parameters of the hybrid joint.

• Transactions of Materials Processing
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• v.10 no.1
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• pp.42-52
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• 2001

The static softening mechanisms of 304 stainless steel were studied by hot torsion test. The interrupted deformation tests were performed In the range of 900~$1100^{\circ}C$ and 5.0$\times$$10^{-2}$- 5.0$\times$$10^0$/sec. The metadynamic recrystallization (MDRX) could be distinguished from the static recrystallization (SRX). Comparison of the softening kinetics between MDRX and SRX showed that the rate of MDRX was more rapid than that of SRX for the same deformation variables. To the exact prediction of MDRX, the MDRX parameter, which could be simultaneously estimated by the interpass time and Zener-Hollomon parameter, was developed. The time lot 50% MDRX, $t_{0.5} was modeled using the deformation parameters : $t_{0.5} = 1.33\times10^{-11}$ $\.\varepsilon^{-0.41}$ D exp(230.3kJ/mol/RT) and the predicted value was very correspondent with the measurement. It was found that the static parameters such as interpass time can control the dynamic states in the several successive deformation process.

• Physical Therapy Korea
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• v.3 no.3
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• pp.1-11
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• 1996

The purpose of this study were to evaluate and compare the balance ability at different conditions in normal 20 to 29 years old on unstable platform, KAT 2000(Breg, Inc., Vista, CA. 1994). Static and dynamic BI(balance index) were measured 3psi and 5psi surface conditions. Static tests were done on right and left leg separately, then both legs together with the feet apart 20cm with the eyes opened and closed. Dynamic tests were done on both legs together with apart 20cm with the eyes opened. A dynamic test was performed in which the subject moved platform in a circular manner to chase a moving object on a computer screen. Seventy healthy students(average 21.6 years, male, female) were tested. In this study applied the paired t-test and correlation to determine the statistical significance of result. The results were as follow: 1) The mean static balance index of the Rt leg was $119.9{\pm}75.72$ on 3psi surface condition with the eyes opened, and that of the Lt leg was $224.3{\pm}121.16$. 2) The mean static balance index of the Rt leg was $93.1{\pm}24.16$ on 5psi surface condition with the eyes opened, and that of the Lt leg was $180.5{\pm}61.76$. 3) The mean static and dynamic balance index of both legs were $76.4{\pm}31.86$, $2187.6{\pm}696.99$ on 3psi with the eyes opened, and $68.3{\pm}14.82$, $1938.7{\pm}525.41$ on 5psi respectively. 4) The mean static balance index of the Rt leg was $517.8{\pm}220.87$ on 3psi surface condition with the eyes closed, and that of the Lt leg was $588.6{\pm}204.81$. 5) The mean static balance index of the Rt leg was $271.9{\pm}192.151$ on 5psi surface condition with the eyes closed, and that of the Lt leg was $363.4{\pm}98.97$. 6) The mean static balance index of both legs was $332.6{\pm}137.31$ on 3psi surface condition with the eyes closed, and that of the 5psi was $288.5{\pm}133.07$. 7) The balance index on 3psi surface condition was significantly higher than that of 5psi (p<0.05, p<0.01). 8) The balance index with the eyes closed was significantly higher than that of the eyes opened (p<0.05). 9) The balance index on the left leg was significantly higher than that of the right leg (p<0.05, p<0.01). 10) There was no correlation between static balance index and dynamic balance index. 11) Therewas no correlation between weight or height and balance index.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.85-93
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• 1993

Base isolation systems are economic and efficient for the control of structural vibration. In this study, the base isolators of LRB(laminated rubber bearing) type which have been generally used are fabricated and tested. From the static and dynamic tests, the characteristics of the base isolators, considering strain-hardening, hysteretic damping and horizontal stiffnesses, etc., are verified and particularly the feasibility as base isolation devices is discussed. Consequently, the test results are compared with the analytical ones that are derived from idealization as a bilinear model.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.4
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• pp.67-74
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• 2006

This study was carried out to investigate the liquefaction behaviour of saturated silty sand under monotonic loading conditions. The undrained soil tests were conducted using a modified triaxial cell and specimens were prepared using the moisture tamping method. Undrained triaxial compression tests were performed at different confining pressures, void ratios and overconsolidation ratios and the samples were sheared to axial strains of about 20% to obtain monotonic loading conditions. It is shown that increasing confining pressures, void ratios and overconsoildation ratios increases the deviator stress, but it has no effect on increasing the dilatant tendencies. It is shown that complete static liquefaction was observed regardless of increases in the confining pressure, void ratio and overconsolidation ratio. Therefore, the confining pressure, void ratio and overconsoildation ratio does not provide significant effects on the liquefaction resistance of the silty sand. The presence of fines in the soil was shown to greatly increase the potential for static liquefaction and creates a particle structure with high compressibility for all cases.