• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1312-1319
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• 2006

This thesis studied the scale effects on bearing capacity and settlement characteristics by using FEM. The conclusions of the study are as follows. 1) For sandy soil, the bearing capacity ratio increased in the form of logarithm as the foundation width increased. Hence application of static mechanic theory results in overestimation of the bearing capacity when the bearing capacity should be derived from plate loading test results. 2) In clayey soil, the characteristics of the bearing capacity associated with foundation width met Terzaghi's bearing capacity theory. 3) In sandy soil, the settlement ratio increased non-linearly as foundation width increased. However, in clayey soil, the settlement ratio increased linearly. 4) In ordinary soil, the foundation width - settlement ratio turned out to be close to that of sandy soil.

• Structural Monitoring and Maintenance
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• 제5권1호
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• pp.93-110
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• 2018

In order to provide a novel strategy for long-span bridge health monitoring system design, this paper proposes a novel ultimate bearing capacity ratios based bridge internal force monitoring design method. The bridge ultimate bearing capacity analysis theories are briefly described. Then, based on the ultimate bearing capacity of the structural component, the component ultimate bearing capacity ratio, the uniformity of ultimate bearing capacity ratio, and the reference of component ultimate bearing capacity ratio are defined. Based on the defined indices, the high bearing components can then be found, and the internal force monitoring system can be designed. Finally, the proposed method is applied to the bridge health monitoring system design of the second highway bridge of Wuhu Yangtze river. Through the ultimate bearing capacity analysis of the bridge in eight load conditions, the high bearing components are found based on the proposed method. The bridge internal force monitoring system is then preliminary designed. The results show that the proposed method can provide quantitative criteria for sensors layout. The monitoring components based on the proposed method are consistent with the actual failure process of the bridge, and can reduce the monitoring of low bearing components. For the second highway bridge of Wuhu Yangtze river, only 59 components are designed to be monitored their internal forces. Therefore, the bridge internal force monitoring system based on the ultimate bearing capacity ratio can decrease the number of monitored components and the cost of the whole monitoring system.

• 한국해양공학회지
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• 제29권1호
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• pp.78-84
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• 2015

Geosynthetics such as geogrids or geotextiles have been widely used to improve the bearing capacity of soft ground. This study investigated the California bearing ratio (CBR) of waste fishing net (WFN)-reinforced sand. CBR tests were carried out to evaluate the improvement in the bearing capacity of WFN-reinforced sand with different embedded depths. The experimental results indicated that the CBR increased as the embedded depth of the WFN decreased. The bearing capacity ratio (BCR) is the ratio of the bearing capacity of reinforced ground to that of unreinforced ground. The BCR at the penetration depths of 2.5 mm, 5 mm, and the peak point decreased with an increase in the embedded depth.

• Steel and Composite Structures
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• 제47권3호
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• pp.437-450
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• 2023

A half open cross section built-up column, namely cold-formed thin-walled steel built-up column with 12-limbsection (CTSBC-12) is put forward. To deeply reveal the mechanical behaviors of CTSBC-12 under axial compression and put forward its calculation formula of axial bearing capacity, based on the previous axial compression experimental research, the finite element analysis (FEA) is conducted on 9 CTSBC-12 specimens, and then the variable parameter analysis is carried out. The results show the FEA is in good agreement with the experimental research, the ultimate bearing capacity error is within 10%. When the slenderness ratio is more than 96.54, the ultimate bearing capacity of CTSBC-12 decreases rapidly, and the failure mode changes from local buckling to global buckling. With the local buckling failure mode unchanged, the ultimate bearing capacity decreases gradually as the ratio of web height to thickness increases. Three methods are used for calculating the ultimate bearing capacity, the direct strength method of AISI S100-2007 gives result of ultimate axial load which is closest to the test and FEA results. But for simplicity and practicality, a simplified axial bearing capacity formula is proposed, which has better calculation accuracy with the slenderness ratio changing from 30 to 100.

• Tribology and Lubricants
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• 제18권3호
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• pp.181-186
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• 2002

A numerical analysis is undertaken to show the influence of bearing design parameters on the load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, and the seal ratio.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.299-306
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• 2001

Crushed Stone Pile(CSP) is one of the ground improvement methods available to loose sand and clayey ground by forming compacted CSP in the weak soil layer. The effects of this method are enhancement of ground bearing capacity, reduction of settlement and prevention of lateral ground movement in cohesive layer, reduction of liquefaction potential in sandy ground. This study performs model tests in 1.0m${\times}$1.0m${\times}$1.0m and 1.5m${\times}$1.5m${\times}$l.2m model tank to observe bearing capacity of CSP treated ground. The area replacement ratio of CSP composite ground varies 20%, 30% and 40% with square grid pattern. After the composite ground was consolidated under pressure of 0.5kg/$\textrm{cm}^2$ and 1.0kg/$\textrm{cm}^2$, load tests were carried out. The results show that ultimate bearing capacity increases with area replacement ratio and the preconsolidation pressure of ground.

• Advances in concrete construction
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• 제10권4호
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• pp.289-299
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• 2020

A reliability analysis of the axial compressive load bearing capacity of postfire reinforced concrete (RC) columns strengthened with carbon fiber reinforced polymer (CFRP) sheets was presented. A 3D finite element (FE) model was built for heat transfer analysis using software ABAQUS. Based on the temperature distribution obtained from the FE analysis, the residual axial compressive load bearing capacity of RC columns was worked out using the section method. Formulas for calculating the residual axial compressive load bearing capacity of the columns after fire exposure and the axial compressive load bearing capacity of postfire columns retrofitted with CFRP sheets were developed. Then the Monte Carlo method was used to analyze the reliability of the axial compressive load bearing capacity of the RC columns retrofitted with CFRP sheets using a code developed in MATLAB. The effects of fire exposure time, load ratio, number of CFRP layers, concrete cover thickness, and longitudinal reinforcement ratio on the reliability of the axial compressive load bearing capacity of the columns after fire were investigated. The results show that within 60 minutes of fire exposure time, the reliability index of the RC columns after retrofitting with two layers of CFRPs can meet the requirements of Chinese code GB 50068 (GB 2001) for safety level II. This method is effective and accurate for the reliability analysis of the axial load bearing capacity of postfire reinforced concrete columns retrofitted with CFRP.

• 산업기술연구
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• 제27권A호
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• pp.121-130
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• 2007

Centrifuge model tests were performed to find appropriate equations proposed previously of estimating the bearing capacity of the composite clayey soil reinforced with sand compaction pile. Model tests were carried out with changing the replacement ratio of SCP (20%, 40%, 70%), contents of fine materials (5%, 10%, 15%) and ratio of treated width to loading width (1B, 2B, 3B). Test results about bearing capacity of the composite ground were obtained by performing the surcharge load tests with measurements of applied loads and vertical displacement. Bearing capacities against bulging and shear failures were estimated by the existing equations. As results of comparing the estimated bearing capacity with experimental values the bearing capacities estimated by Greenwood's equation (1970) for bulging failure mode were similar to the test results.

• 한국지반공학회논문집
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• 제35권3호
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• pp.17-24
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• 2019

본 연구는 지반 위 얕은 기초의 지지력에 대한 특성을 파악하기 위하여 지반 조건, 기초 크기, 기초 형상 등의 다양한 조건에 대하여 3차원 유한요소해석을 수행하여 기존의 지지력 이론과 비교 검토하였다. 유한요소해석 결과 극한지지력은 기초크기에 따라 지지력이 거듭제곱이나 로그 식으로 차츰 수렴하였고, 지반강도가 증가할수록 지지력 증가가 커지지 않는 직선적인 변화를 보였다. 기존 지지력 이론과 비교한 결과 순수모래는 지지력 비($q_{FEA}/q_{theory}$)가 Terzaghi식의 결과와 가장 유사하였다. 순수점토는 약 0.4~0.6, 일반토사는 0.3~1.3 정도로 산정되었고, 지반강도가 증가할수록 지지력 비가 감소하면서 1.0 이하로 나타났다. 기초 크기에 따른 지지력을 1.0m 기초의 지지력으로 정규화시킨 지지력 비($q_u/q_{u(1.0)}$)는 순수모래에서 ${\phi}=25^{\circ}$, $30^{\circ}$, $35^{\circ}$일 때 이론식의 35%, 15%, 5% 정도로 산정되었고, 순수점토는 크기 효과가 없었으며, 일반토사는 지반강도가 작은 경우에 순수모래의 이론식에 대해 약 10% 이하로 나타났다. 지반강도 증가에 따른 지지력 비는 내부마찰각의 영향이 큰 것으로 나타났다. 기초형상별 지지력 비에 따른 형상계수는 기초형상에 따라 다르게 나타났고, 원형기초는 1.5, 정사각형 기초는 1.3, 직사각형 기초와 연속 기초는 1.1~1.0의 형상계수를 나타내었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.257-262
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• 2001

A numerical analysis is undertaken to show tile influence of bearing design parameters on tile load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, arid the seal ratio.