• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.3
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• pp.141-150
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• 1998

Model tests were performed to examine the mechanical behavior of steel circular caisson by horizontal load. It was generally found that displacements and bottom pressure of the caisson model were increased rapidly at the local plastic load. The maximum displacement was measured at the loading point, whereas the less displacement was measured at the upper part of the caisson model. The bottom pressure was getting higher, as it was nearer the loading side. Furthermore, the increase ratio of the bottom pressure was higher as the load was increased.

• Journal of the Korean Geotechnical Society
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• v.35 no.11
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• pp.25-36
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• 2019

The safety barrier is installed on road embankment to prevent vehicles from falling into road side slope. Among the safety barrier, flexible guardrails are usually installed. The flexible guardrail generally consists of a protection cross-beam and supporting in-line piles. These guardrail piles are installed nearby slope edge of road embankment because the side area of the road is much narrow. The protection cross-beam absorbs impact energy caused by vehicle collision. The pile-soil interaction also absorbs the rest of the impact energy and then, finally, the flexible guardrail system resists the impact load. This paper aims to investigate the pile-soil interaction subjected to impact load using centrifuge model tests. In this study, a single pile was installed in compacted residual soil and loaded under lateral impact load. An impact loading system was designed and developed available on centrifuge tests. Using this loading system, a parametric study was performed and the parameters include types of loading and ground. Finally, the ultimate bearing capacity of supporting pile under impact load was analyzed using load-displacement curve and soil reaction pressure distributions at ultimate were evaluated and compared with previous studies.

• Geotechnical Engineering
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• v.13 no.5
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• pp.59-74
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• 1997

This paper shows the results of a series of model bests on the behavior of single steel pipe pile which is subjected to lateral load in Nak-dong river sand. The purpose of the present paper is to estimate the effect of Non -homogeneous soil, constraint condition of pile head, lateral load velocity, relative density of soil, embedded pile length, and flexural stiffness of pile on the behavior of single pile which is embedded in Nak-dong river strand. These effects can be quantined only by the results of model tests. The nonlinear responses of lateral loadieflection relationships are fitted to 2nd polynomial equations by model tests results. Also, the lateral load of a deflection, yield and ultimate lateral load max. bending moment, and yield bending moment can be expressed as exponential function in terms of relative density and deflection ratio. By comparing Brom's results with model results on the lateral ultimate load, it is found that short and long pile show the contrary results with each other. The contrary results are due to the smaller assumed soil reaction than the soil reaction of the Nakiong river sand at deep point. By comparing lateral behavior on the homogeneous soil with non-homogeneous soil, it is shown that lateral loadieflection relationship is very dependent on the upper relative density. This phenomenon is shown remarkably as the difference between upper and lower relative density increases.

• Computational Structural Engineering
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• v.3 no.1
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• pp.109-116
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• 1990

Live load data in domestic office buildings have been collected in a systematic manner. Based on surveyed data, equivalent uniformly distributed load intensities, which produce the same load effect as the actual spatially varying, live load, have been obtained for various structural members (such as slab, beam, column, etc. ). Influence surface method has been employed to compute load effects under real live load, including beam moment, slab moment as well as axial force in column. The results have been examined to find probabilistic characteristics and relationship between influence area and load intensity (or coefficient of variation). The results were also compared with other survey results and found to be reasonable. Based on the probabilistic load models obtained, the lifetime extreme values have been analyzed and compared with current design loads. Tentative equations applicable to decide more rational design loads are also suggested as functions of influence area.

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.191-205
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• 2017

We use small-scale modelling to estimate the impact ofrce of debris flows on erosion control dams (ECD) and ring nets. The results indicate that the viscoelastic debris flows produced impact forces of 4.14, 3.66, 1.66 kN from the bottom to the top of the ECD. Ring net tests produced a similar trend with generally smaller impact forces (2.28, 1.95, and 1.49 kN). Numerical analysis showed that the weight of the ECD (e.g., concrete retaining walls) provided resistance against the debris flow, whereas deformation of the ring net by elastic-elongation and aggregate penetration reduced the impact force by up to 45% compared with that of the ECD.

• Computational Structural Engineering
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• v.1 no.2
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• pp.101-109
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• 1988

The evaluation of the system reliability is generally quite difficult and costly as the structure becomes large and complex, especially when it is subjected to multiple time varying loads, and for redundant structures which have many possible modes of failur, e.g., system collapse through the formation of plastic hinge mechanisms. In reality most loadings acting on the structures are random in intensity as well as in occurrence time and duration. To include the load variability in time, the loads are described in terms of stochastic processes. Based on a tri-modal upper bound, a point estimate for the system reliability has been developed for more accuracy without extensive computational effort. This tri-modal point estimate also ensures the continuity of the system reliability function, which is a necessary condition in many nonlinear programming techniques. In addition, the Load Coincidence method, by which the combined effect of time varying loads are taken into account, has been modified to suitable for cases with an always-on load.

• 한국기계연구소 소보
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• s.12
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• pp.49-61
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• 1984

대양을 항해하는 Puser-Barge선의 내항성능과 그연결장치에 작용하는 피랑하중을 추정하기위하여,규칙피중 선체운동응답과,파랑하중응답을 Strip이론으로 구하는 해석적인 방법을 개발하였다. 연결장치의 종류로는 2개의 핀으로 연결되는 힌지연결의 경우와, 3개의 핀으로 연결되는 고정연결의 경우를 고려하였다. 이론 계산결과를 확인하기 위한 모형시험을 힌지연결의 경우에 대하여 정면규칙파중에서 실시하였다. 실험결과와 이론계산결과는 비교적 잘 일치하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.372-376
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• 2005

본 연구에서는 다양한 유량 조건 하에서 수로의 만곡이 존재하고 하중토가 존재하는 비교적 복잡한 지형에 대한 수리모형실험에 LSPIV기법과 기존 점유속계(2차원 전자기유속계)를 함께 적용하고 그 결과를 비교하여 복잡한 흐름에 대한 LSPIV의 적용성을 검토하였다. LSPIV를 이용한 표면유속장과 2차원 전자기유속계를 이용하여 1점법으로 측정된 유속장을 비교할 때, 수로 만곡과 같은 지형적 특성으로 인한 유속분포의 특성이 유사하게 관측되었으며, 홍수시의 주변고수부지 및 하중도 침수로 인해 복잡한 흐름구조가 발생하는 경우에는 LSPIV를 이용한 표면유속장 측정을 통하여 흐름특성을 더욱 명확하게 관찰할 수 있었다. 측정된 유속자료 및 하도단면자료를 이용하여 홍수량을 산정해 본 결과 하도횡단면이 비교적 단순한 경우에는 표면유속과 점유속을 이용해 계산한 홍수량 간의 차가 크지 않았으나 하도단면이 복잡한 경우에는 계산된 홍수량 사이의 차가 크게 나타났다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3100-3105
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• 2010

The permanent deformation of asphalt pavement is one of the most important load-related distresses in asphalt pavement. In order to evaluate the permanent deformation, the repeated triaxial load test with different temperature and air void of hot mix asphalt was carried out. The permanent deformation prediction model has been validated by the multiple regression approach and the artificial neural networks.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.04a
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• pp.13-18
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• 1992

구조물의 동적실험을 통하여 얻은 하중과 거동에 대한 시간기록을 분석하여, 구조계의 동 특성계수들을 추정하는 기법에 대하여 연구하였다. 실험과정 및 해석모형과정의 오차를 고려하기 위하여, 하중기록과 구조거동기록간의 관계를 추계론적 자동회기 및 이동평균모형(Stochastic Auto-Regressive and Moving-Average (ARMAX) Model)음 사용하여 모형화하였다. 미지의 ARMAX 계수행렬들은 순차적 예측오차기법을 사용하여 추정하였으며, 계수추정기법의 효율성을 증진시키기 위하여, Exponential Data Weighting, Global Data Weighting 및 Square Root Estimation 기법을 활용하였다. 다중거동측정계의 예제해석을 통하여 이의 효율성을 분석하였다.