• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.71-79
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• 2008

The underground conduit laid under different environments exhibits various behaviour according to the ground and external load as well as the loading time and conditions, so on. As the environmental conditions are usually different even within the same area, it is very difficult to correctly predict the stress conditions and behaviour of the underground conduit using currently available theoretical analysis. Especially, it is not yet satisfied in Korea for the evaluation of the underground conduit under the influence of the load of vehicles or unexpected loading conditions. Thus, in this study the assessment for the excavation depth and ground disturbance was carried out with a large box model test and numerical analysis. Numerical analysis was also performed for the assessment of dynamic loading conditions like railway load.

• Journal of the Korean Geotechnical Society
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• v.27 no.3
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• pp.5-17
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• 2011

Sampling disturbance can often introduce considerable errors in the laboratory estimation of geotechnical properties of soils. Accordingly, it causes inappropriative results in analysing field behavior. Therefore, a screw plate load test, one of in-situ test technique, is developed in this study, because in-situ testing techniques have advantages for the estimation of reliable geotechnical parameters. The screw plate load test, which was modified from the plate load test, conducts an experiment underneath ground by inserting a spiral type of auger screw. In this study, the structure and characteristics of the screw plate load test device are introduced in detail and the reliability of the device is examined through the analysis of the laboratory test results.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.211-222
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• 2019

This study evaluates the yield load and allowable bearing capacity of ground in compressive loading tests to confirm the effect of CPR foundation reinforcement. The average compressive strength of the injection materials was higher than the planned compressive strength. Standard penetration tests for each stratum showed that foundation reinforcement improved the average N values, thereby increasing the bearing capacity of the ground. Compressive loading tests on two CPR piles revealed that the total and net settlement due to the maximum load exceed that permissible for the CPR pile diameter. The yield load and allowable bearing capacity calculated by the settlement criterion and the load-settlement curves varied greatly with the method applied. Therefore, it seems to be necessary to determine the optimum value through comprehensive analysis after applying various yield load calculation methods.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.26-33
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• 2020

This study measured the downward stepping movement relative to weight change (no load, and 10%, 20%, 30% of body weight respectively of adult male (n=10) from standardized stair (rise of 0.3 m, tread of 0.29 m, width of 1 m). The 3-dimensional cinematography and ground reaction force were also utilized for analysis of leg stiffness: Peak vertical force, change in stance phase leg length, Torque of whole body, kinematic variables. The strategy heightened the leg stiffness and standardized vertical ground reaction force relative to the added weights (p<.01). Torque showed rather larger rotational force in case of no load, but less in 10% of body weight (p<.05). Similarly angle of hip joint showed most extended in no-load, but most flexed in 10% of body weight (p<.05). Inclined angle of body trunk showed largest range in posterior direction in no-load, but in vertical line nearly relative to added weights (p<.001). Thus the result of the study proved that downward stepping strategy altered from height of 30 cm, regardless of added weight, did not affect velocity and length of lower leg. But added weight contributed to more vertical impulse force and increase of rigidity of whole body than forward rotational torque under condition of altered stepping strategy. In future study, the experimental on effect of weight change and alteration of downward stepping strategy using ankle joint may provide helpful information for development of enhanced program of prevention and rehabilitation on motor performance and injury.

• Journal of the Korean Geotechnical Society
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• v.24 no.11
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• pp.55-60
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• 2008

This paper presents how the load transfer mechanism of the ground anchor affects on the stability analysis of anchored slope. The finite element analysis and the conventional limit equilibrium analysis on the anchored slope were performed and compared. The limit equilibrium analysis of the anchored slope is widely used in design practice due to the easiness of the analysis. However, the load transfer mechanism is not considered properly for the analysis. When the failure surface passes through the bonded length of an anchor, the anchor load is disregarded and the factor of safety for the anchored slope is smaller than it should be. In this study, the load transfer distribution was incorporated into the limit equilibrium stability analysis of the anchored slope and the results were compared with those of finite element analysis.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.7
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• pp.355-362
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• 2003

The fault analysis problem of a distribution network has many difficulties comes from the unbalance of loads or networks and the lacks of load information. The unbalance of loads or networks make the fault location difficult when it use the classical sequence transformation. Moreover the amount of load in the distribution networks fluctuates with time. This paper introduces a recent fault location algorithm using iterative method which handle the unbalance of the problem. But, the fault location errors comes from the load fluctuations still left. For the real application of the new fault location algorithm in distribution networks, this paper studied the effect of the load fluctuations in the algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.478-485
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• 2001

A dynamic load simulator(DLS) which can reproduce on-ground the aerodynamic hinge moment of control surface is an essential rig for the performance and stability test of aircraft actuation system. By setting up load actuator as counter acting with the control surface driving actuator and designing an appropriate force control system for load actuator, DLS can be mechanized. Obtaining an accurate mathematical model for the DLS is the first step to successfully design an aerodynamic load replicati on system. Two theoretical models are presented and tested for their validities with the experimental results, which turns out to be not successful. An alternative way of using system identification approaches in investigated to develop a good nominal model for DLS dynamics, and suitable uncertainty bounds for this nominal model are proposed with the consideration of experimental results.

• Structural Engineering and Mechanics
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• v.33 no.5
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• pp.589-604
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• 2009

In the field of predicting structural safety and reliability the operating conditions play an essential role. Since the time and cost limitations are a significant factors in engineering it is important to predict the future operating conditions as close to the actual state as possible from small amount of available data. Because of the randomness of the environment the shape of measured load spectra can vary considerably and therefore simple distribution functions are frequently not sufficient for their modelling. Thus mixed distribution functions have to be used. In general their major weakness is the complicated calculation of unknown parameters. The scope of the paper is to investigate the load spectra growth for actual operating conditions and to investigate the modelling and extrapolation of load spectra with algorithm for mixed distribution estimation, REBMIX. The data obtained from the measurements of wheel forces and the braking moment on proving ground is used to generate load spectra.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.901-905
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• 2008

This study was conducted to clarify the heat load characteristics and heat and moisture behavior of underground structures. The authors achieved this by carrying out a numerical analysis using simple heat diffusion and simultaneous heat and moisture transfer equations based on measurement data. This paper presents the results of a numerical analysis on the heat load characteristics and heat and moisture behavior of an underground basement and its surrounding ground under a condition of internal heat generation. The authors found it difficult to predict the heat behavior and heat load of the underground basement by simple heat diffusion alone. Accurate prediction of the thermal environment and heat load requires careful consideration of the influences of moisture and precipitation

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6C
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• pp.231-240
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• 2011

Various pile load tests were carried out at Gwangyang district for 10 different piles in order to analyze the characteristcs of steel pile using high strength steel and high driving energy. Pile drivability results showed that PHC piles needed highest total blow count even with the shortest pile length and high strength steel pipe piles showed smallest total blow count eventhough driven to a more hard ground condition with longer pile length. Pile dynamic analysis results showed that for PHC pile and general steel pipe pile the allowable pile design load was decided by the allowable material strength but for high strength steel pipe pile the design load can be decided according to the ground bearing capacity. Static load test and load transfer test results showed that the pile design efficiency could be improved over 80% allowing lesser number of piles necessary for a more economical solution. Set-up effects was analyzed and regression equation for the site ground condition was derived. Bearing capacity was checked with widely used design equation and the limitation of current design method and future technology development on this subject is dicussed in this paper.