• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.273-273
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• 2002

Masan barber was situated in S.Korean southern central coast. And it is contributing greatly in S.korea's economy development to international trading port of Heaven's blessing that possess natural, geographical situation. Also, because there are Masan free tax area and chanwon heavy industrial complex, sachon air industrial complex etc. on back, it is important permanency in our country. Specially, because inland transport routes such as southern highway, Guma highway and national road system are developed well, the importance is very high. Masan harbor 1899.05.01 be that opened, the 1st and 2nd (central pier) was build 1938∼1944 year, and the 3rd pier was 1973∼1978 year. the 4th pier was 1974∼1983 year, 5th pier was 1984∼1988, 6th pier (west pier) was 1985∼1992 year. it was developed over 100 years. But, it did great many harbor and bay development of last 100 yens but research about coastline change and seashore reclamation is insufficient. Therefore, this research executed research about coastline change of Masan bay of last 100 years, In this study, we analyzed aerial photographs and tide data for the past 100 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area As a result, we drew 10 years cycle coastline change of Masan bay. and we can detect bay coastal line change and calculate refill rate.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.245-248
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• 2001

During the core drilling for the design of a railway bridge crossing over the inferred fault system along the river, fracture zone, extends vertically more than the bottom of borehole, filled with fault gouge was found. The safety of bridge could be threatened by the excessive subsidence or the reduced bearing capacity of bedrock, if a fault would be developed under or around the pier foundation. Thus, a close examination of the fault was required to rearrange pier locations away from the fault or to select a reinforcement method if necessary. Geophysical methods, seismic reflection method and electrical resistivity survey over the water covered area, were applied to delineate the weak zone associated with the fault system. The results of geophysical survey clearly showed a number of faults extending vertically more than 50m. Reinforcement was not desirable because of the high cost and the water contamination, etc. The pier locations were thus rearranged based on the results of geophysical surveys to avoid the undesirable situations, and additional core drillings on the rearranged pier locations were carried out. The bedrock conditions at the additional drilling sites turned out to be acceptable for the construction of piers.

• Earthquakes and Structures
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• 제19권4호
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• pp.287-301
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• 2020

Fragility as one of the most effective methods to evaluate seismic performance, which is greatly affected by damage index. Taking a multi span continuous rigid frame offshore bridge as an example. Based on fragility and reliability theory, considering coupling effect of time-varying durability damage of materials and time-varying attenuation effect of damage index to analyze seismic performance of offshore bridges. Results show that IDA curve considering time-varying damage index is obviously below that without considering; area enclosed by IDA of 1# pier and X-axis under No.1 earthquake considering this effect is 96% of that without considering. Area enclosed by damage index of 1# pier and X-axis under serious damage with considering time-varying damage index is 90% of that without considering in service period. Time-varying damage index has a greater impact on short pier when ground motion intensity is small, while it has a great impact on high pier when the intensity is large. The area enclosed by fragility of bridge system and X-axis under complete destruction considering time-varying damage index is 165% of that without considering when reach designed service life. Therefore, time-varying attenuation effect of damage index has a great impact on seismic performance of bridge in service period.

• Earthquakes and Structures
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• 제27권1호
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• pp.69-82
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• 2024

In the conventional seismic design approach for a bridge pier, the function of the stopper, and shear key are to serve as mechanisms for unseating prevention devices that retain and transmit the lateral load to the pier under strong earthquakes. This frequently inflicts immense shear forces and bending moments concentrated at the plastic hinge zone. In this study, a shear panel damper plus gap (SPDG) is proposed as a low-cost alternative with high energy dissipation capacity to improve the seismic performance of the pier. Therefore, this study aimed to investigate the seismic performance of the pre-stressed concrete I girder (PCI-girder) bridge equipped with SPDG. The bridge structure was analyzed using nonlinear time history analysis with seven-scaled ground motion records using the guidelines of ASCE 7-10 standard. Consequently, the implementation of SPDG technology on the bridge system yielded a notable decrease in maximum displacement by 41.49% and a reduction in earthquake input energy by 51.05% in comparison to the traditional system. This indicates that the presence of SPDG was able to enhance the seismic performance of the existing conventional bridge structure, enabling an improvement from a collapse prevention (CP) level to an immediate occupancy (IO).

• Structural Engineering and Mechanics
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• 제28권1호
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• pp.1-18
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• 2008

The conventional design of bridge piers against scour uses scour equations which involve number of uncertain flow, sediments and structural parameters. The inherent high uncertainties in these parameters suggest that the reliability of piers must be assessed to ensure desirable safety of bridges against scour. In the present study, a procedure for the reliability assessment of bridge piers, installed in main and flood channels, against scour has been presented. To study the influence of various random variables on piers' reliability sensitivity analysis has been carried out. To incorporate the reliability in the evaluation of safety factor, a simplified relationship between safety factor and reliability index has been proposed. Effects of clear water (flood channel) and live bed scour (main channel) are highlighted on pier reliability. In addition to these, an attempt has also been made to explain the failure of Black mount bridge of New Zealand based on its pier's reliability analysis. Some parametric studies have also been included to obtain the results of practical interest.

• 기술발표회
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• 통권2006호
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• pp.75-85
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• 2006

The project comprised the construction of the new oil pier and associated topside facilities and demolition of exiting south pier. The site is located approximately 33km south of Kuwait city at MAA refinery. The approach trestle and berth structures of the new oil pier were designed to be supported by steel tubular piles Total 2,480 numbers of piles(795 piles at Approach Trestle, 1187 piles at Berth 1 -4 and 498 piles at Berth 5-6) had to be driven through the calcareous silty sand In this study, the design procedures for offshore steel pipe piles, evaluation for the compression and tension capacities by static and dynamic load test and effective driving criteria by the final set values are discussed

• Earthquakes and Structures
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• 제16권4호
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• pp.391-399
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• 2019

Residual deformation of high-speed railway bridge piers is cumulative under repeated earthquakes, and influences the safety and ride comfort of high-speed trains. This paper investigates the effects of the peak ground acceleration, longitudinal reinforcement ratio, and axial compression ratio on the cumulative deformation through finite element analysis. A simply-supported beam bridge pier model is established using nonlinear beam-column elements in OpenSees, and validated against a shaking table test. Repeated earthquakes were input in the model. The results show that the cumulative deformation of the bridge piers under repeated earthquakes increases with the peak ground acceleration and the axial compression ratio, and decreases with the longitudinal reinforcement ratio.

• Water Engineering Research
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• 제1권2호
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• pp.159-168
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• 2000

In this paper, the increment of the local scour depth at piers by constructing the bridge between existing bridges is examined through the experiments in which 5 piers in the non-cohesive bed material in the experimental flume were installed. In the experiments the maximum distance of 25 times of the pier length and the maximum distortion width of 8 times of the pier width were utilized. Through the experimental studies, it was indicated that low flow, which can be characterized as the flow having low Froude numbers, the maximum bed configuration change is obtained when the piers are installed in the straight line in the flor direction without any distortion. However, In the high flow, which can be characterized as the flow having high Froude numbers, the maximum bed configuration change is obtained when the piers are installed with some distortion from the flow direction. The influence of the bed configuration by interaction between bridge piers is changed depending upon the Froude numbers, the distance between piers, and the distortion width between adjacent bridge piers. Also, because the scour patterns are affected by the bed configuration, the maximum scour should be increased by about 60% compared to that in a single pier if the interaction between bridge piers exists. It can be suggested that the maximum scour depth at bridge piers predicted by applying the existing equations should be increased if the interaction between bridge piers exist. Those cases are found when new bridges are constructed successively in the river in the urban area.

• 한국방재학회 논문집
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• 제9권4호
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• pp.91-97
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• 2009

하천을 횡단하는 구조물들은 흐름을 변화시킬 뿐 아니라, 산지 및 중소하천에서 유송잡물로 인한 수위 상승의 원인을 제공하기도 한다. 이번 연구에서는 유속 및 경사 등의 하천특성인자와 교각의 영향으로 변화되는 흐름을 2차원 모형으로 분석하였다. 또한 강우로 인해 변화된 유량이 흐름에 미치는 영향도 비교하였다. 하도내의 유속은 SMS (Surface water Modeling System) 및 RMA2 모형을 통해서 분석할 수 있었으며, 경사가 크고, 하도의 폭이 좁은 구간에서 비교적 유속이 큰 것으로 나타났다. 또한 교각 주변에서는 교각과 교각 사이의 중심부에서 유속이 가장 크게 나타났다. 강우로 인해 증가된 유량은 유속을 증가시키고 흐름 분포를 현저하게 변화시키는 것을 확인할 수 있었다.

• 한국조경학회지
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• 제43권4호
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• pp.15-26
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• 2015

본 연구는 대구도시철도 3호선의 교각미관개선 시험구간을 대상으로 경관 개선을 위한 방안을 제안하고자 하였다. 연구방법은 교각에 대한 인식과 디자인 시 중요요소를 조사하고, 코팅, 그래픽, 피복식물, 광고판 등의 선호도 및 감성평가를 실시하였다. 경전철의 교각은 평가자들의 60.4%가 부정적으로 인식하고 있으며, 미관개선이 필요한 것으로 조사되었다. 교각디자인 시 고려해야할 시각적 요소는 색채 5.81, 형태 5.57, 미적구성 요소에는 조화 6.07, 쾌적성 6.00 등의 순서로 높게 나타났다. 미관개선별 선호도는 그래픽 4.14, 피복식물 3.57, 코팅 3.23, 광고판 2.82 등의 순서로 분석되었으나, 연구대상지 피복식물은 생육이 나빠 피복율이 낮은 상태에서 이루어진 점을 고려해야 할 것으로 판단된다. 감성평가에서 코팅, 안전시설, 무처리는 '인공적인', '생기없는', '삭막한'이 대표적인 경향으로 나타났고, 자연재료를 사용한 피복식물은 타 유형에 비해 '자연적인', '생기있는'이 높은 것으로 분석되었다. 반면, 그래픽과 광고판은 대표적인 감성 요소 없이 디자인에 따라 상이한 것으로 나타났다. 교각 미관개선을 위해서는 우선적으로 주변 환경과 조화로움, 이용자의 정감성을 고려할 필요가 있으며, 본 연구의 결과는 경전철 교각의 경관문제 개선에 필요한 기초자료로 활용할 수 있을 것으로 기대된다.