• Geomechanics and Engineering
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• v.3 no.2
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• pp.153-167
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• 2011

Traditional design methods of bearing capacity of shallow foundations are deterministic in the sense that they do not explicitly consider the inherent uncertainty associated with the factors affecting bearing capacity. To account for such uncertainty, available deterministic methods rather employ a fixed global factor of safety that may lead to inappropriate bearing capacity predictions. An alternative stochastic approach is essential to provide a more rational estimation of bearing capacity. In this paper, the likely distribution of predicted bearing capacity of strip footings subjected to vertical loads is obtained using a stochastic approach based on the Monte Carlo simulation. The approach accounts for the uncertainty associated with the soil shear strength parameters: cohesion, c, and friction angle, ${\phi}$, and the cross correlation between c and ${\phi}$. A set of stochastic design charts that assure target reliability levels of 90% and 95%, are developed for routine use by practitioners. The charts negate the need for a factor of safety and provide a more reliable indication of what the actual bearing capacity might be.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.117-132
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• 1994

Drivers select approach lane according to various traffic situations as well as their destination. This behavior affects the utilization of lanes and capacity analysis at urban signalized intersections. This paper presents the concept, behavior of lane utilization, and the lane utilization factors which included in the study. Preparation of Korean Highway Capacity Manual (1992). Lane utilization is affected by various traffic and geometric factors which are roadway side friction, median friction, and number of lanes, etc. and it converges to an equal utilization as the degree of saturation (V/C ratio) increase. Lane utilization factor is suggested by the degree of saturation and the number of lanes, and it is presented in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.769-774
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• 2000

The first thing in developing precast post-tensioned concrete frame system verify the shear resistance capacity of the beam-column connection at which the transfer of member forces become discontinuous. Complying with the necessity of such experimental research, shear tests have been performed for six test specimens which were cast and cured at Dong-Ah Concrete Manufacturing Company and post-tensioning at Concrete Laboratory of Inha University. Shear key and magnitude of post-tensioned force are taken test variables. From the test results, it has been observed that the shear resistance of the specimens attained to higher values than those of theoritical calculations based on the shear friction with shear friction coefficient being 0.6.

• The KSFM Journal of Fluid Machinery
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• v.5 no.2 s.15
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• pp.43-49
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• 2002

In this paper, the steady-state performances analysis of a tilting pad gas bearing(TPGB) we analyzed by using finite element method for compressible Reynolds' equation. TPGB is used in a high-expansion-ratio expander running at a speed of 230,000 rpm. In order to solve the nonlinear finite element equations, the Newton-Raphson method is applied. The variations of the loading capacity, friction force and tilting angle of a single pad v.s. eccentricity direction of eccentricity and bearing number are investigated. The condition for the equilibrium of a pad, which is important for safe working of the bearing, is stated. The performances of the three pad bearing such as loading capacity, friction moment are predicted.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.435-442
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• 2002

Fluid Confirmation Tests(FCT) on 1500 ground Anchors install in weathered rock were carried out to investigate upper and lower limit of elastic elongation, frictional resistant of fixed anchor body, mobilized angle between anchor body and soil. All the measured data were analysed and compared with theoretical equations. The frictional angles of diaphragm wall and anchorage system in weathered rock showed nonlinear curve between upper and lower limit of standard elongation. The FCT results indicated that the frictional resistant angles increased with higher values of surcharge load. The quality assurance on the fixed anchor location was investigated by means of measuring elastic elongation during the FCT, and comparing these with theoretical design length, the quality of anchors in this particular site found to be above average standard. The results of this research works with provide valuable guide line on quality assurance of anchors system as well as resonable prediction of friction resistance between the fixed anchor body and the weathered rock.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.482-485
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• 2004

A Performance Based Design procedure for retrofitting the RC frame with friction dampers is described. The Capacity Diagram Method procedure is used to estimate the inelastic response of the example model. The example models were retrofitted using SBC dampers and the retrofitted example models were computation ally modeled. The results show that the performance of the retrofitted frame satisfies the target objective.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.372-377
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• 2000

Recently, fluid bearing have been studied to apply to spindle motors for hard disk drive, printer and others. Since fluid bearing have excellent stiffness and good load carrying capacity, the bearing proved to be suitable for those devices related to computer industry. In this paper, the friction and wear characteristics of the bearing were studied. The bearing appears good performance at a high temperature and high wear resistance.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.167-174
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• 1998

• Proceedings of the Korean Geotechical Society Conference
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• 1996.03a
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• pp.145-154
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• 1996

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.425-426
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• 2002

Lineal and angular movements of many engine components make the lubricant absorb air and the aerated lubricant greatly influences the clearance performance of contacting behaviors of engine components such as big-end bearing, cam and tappet, etc. This study investigates the behaviors of aerated lubricant in the gap between con-rod bearing and proceeding which is one of the most frictional energy consuming components in the engine. Our assumption for the analysis of aerated lubricant film is that the film formation is influenced by the two major factors. One is the density characteristics of the lubricant due to the volume change of lubricant by absorbing the bubbles and the other is the viscosity characteristics of the lubricant due to the surface tension of the bubble in the lubricant. In our investigation, it is found that these two major factors surprisingly increase the load capacity in certain ranges of bubble sizes and densities. Frictional forces are also influenced by the aerated bubble size and density, which eventually enlarge the shear resistance due the surface tension, Modified Reynolds' equation is developed for the computation of fluid film pressure with the effects of aeration ratio under the dynamic loading condition. From the calculated load capacity by solving modified Reynolds' equation, proceeding locus is computed with Mobility method at each time step.