• 비파괴검사학회지
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• 제26권6호
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• pp.373-379
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• 2006

Vibration-based structural health monitoring is one of non-destructive evaluation (NDE) techniques for civil infrastructures. This paper presents a novel fiber optic accelerometer system to monitor civil engineering structures and a successful application of the novel sensor system for measuring ambient vibration of a real building structure. This sensor system integrates the Moire fringe phenomenon with fiber optics to achieve accurate and reliable measurements. The sensor system is immune to electromagnetic (EM) interference making it suitable for difficult applications in such environments involving strong EM fields, electrical spark-induced explosion risks, and cabling problems, prohibiting the use of conventional electromagnetic accelerometers. A prototype sensor system has been developed, together with a signal processing software. The experimental studies demonstrated the high-performance of the fiber optic sensor system. Especially, the sensor was successfully used for monitoring a real building on UCI (University of California Irvine, USA).

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.342-345
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• 2009

연안역이란 해안선을 기준으로 인접해 있는 육지(연안지역)와 바다(연안해역)를 포함한 자연환경 대이다. 건설교통부는 연안역의 공간이동 효율성을 높이고 부존해양자원의 체계적인 개발과 보전을 위해 "연안역관리법"특별법으로 관리한다. 하지만 연안역의 안전시설물에 대한 체계적인 설계지침이나 유지관리 등의 지침서가 아직 만들어지지 않았다. 따라서 현재 연안역 설치되어 있는 안전시설물에 대한 실태조사를 통해 안전시설물의 성능저하의 원인분석을 하였다. 본 연구에서는 설치된 안전 시설물들의 철저한 현장조사를 바탕으로 안전 시설물들의 성능저하의 원인을 시설물별로 분석하여 적절한 설계지침을 마련할 토대를 제시하고자 한다.

• 한국측량학회지
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• 제33권6호
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• pp.589-594
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• 2015

In reflection of road expansion and increasing use rates, interest has blossomed in predicting driving environment. In addition, a gigantic scale of big data is applied to almost every area around the world. Recently, technology development is being promoted in the area of road traffic particularly for traffic information service and analysis system in utilization of big data. This study examines actual cases of road management systems and road information analysis technologies, home and abroad. Based on the result, the limitations of existing technologies and road management systems are analyzed. In this study, a development direction and expected effort of the prediction of road information are presented. This study also examines regression analysis about relationship between guide name and traffic volume. According to the development of driving environment prediction platform, it will be possible to serve more reliable road information and also it will make safe and smart road infrastructures.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.907-910
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• 2010

This study has developed a numerical analysis technique newly which can evaluate the damage propagation characteristics of civil infrastructures. To do this, numerical techniques are incorporated for the concrete members up to the compressive damage due to the bending compressive forces after the tensile crack based on the deformation mechanism. Especially, for the compressive damage stage after the tensile crack, the crack propagation process will be analyzed numerically using the concept of an equivalent plastic hinged length. Using this concept, we investigate the reasonability of the developed module by comparing commercial program for the tunnel structure. It can be established from this study that section forces, such as axial forces and the moment cracks takes place, can be related to the width of the crack making it possible to analyze the crack extension.

• International Journal of Concrete Structures and Materials
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• 제3권1호
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• pp.33-37
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• 2009

Fiber Bragg grating (FBG) sensors already have been the focus for structural health monitoring (SHM) due to their distinguishing advantages. However, as bare optical fiber is very fragile, bare FBG strain sensor without encapsulation can not properly be applied in practical infrastructures. Therefore encapsulation techniques for making encapsulated FBG strain sensor show very important in pushing forward the application of FBG strain sensors in SHM. In this paper, a simplified approximate method to analyze the stress transferring rules for embedded FBG strain sensors in concrete monitoring is put forward according to mechanics of composite materials. Shear lag theory is applied to analyze the stress transferring rule of embedded FBG strain sensor in measured host material at the first time. The measured host objects (concrete) and the encapsulated FBG strain sensor are regarded as a composite, and then the stress transfer formula and stress transfer coefficient of encapsulated FBG strain sensor are obtained.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.337-349
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• 2009

In recent years, the cutting and banking areas along the railway in Korea are exposed to the erosion problem during every year. The reinforcement is a composite construction material in which the strength of engineering fill is enhanced by the addition of strong tensile reinforcement in many different types. Various problems of the railway infrastructure have occurred due to the differential settlement, frost heaving, mud pumping, lack of bearing capacity, partially loss of embankment. In advanced countries, railway roadbed reinforcement is applied to solve these problems on railway roadbed. This paper presents the solution of such problems by means of the engineering works incorporated with railway reinforcement infrastructures such as geotextile bag method, existing grouting method, geocell, reinforced earth, soil nailing and so on.

• KCI Concrete Journal
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• 제11권3호
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• pp.109-114
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• 1999

Recently the interest in the safety assessment of civil infrastructures has increased. As bridge structures become large-scale, it is necessary to monitor and maintain the safety of large bridges, which requires smart systems that can make long-term monitoring a reality . Civil engineers have applied monitoring systems to several bridges, such as the New Haeng-Ju Bridge and Riverside Urban Highway Bridge, but these applications have some problems with the sensors for long-term measurement, setup techniques for the bridge monitoring system and the assessment of measured data. In the present study, an optical fiber sensor smart system was tested and confirmed in laboratory tests on the concrete members. By Attaching optical fiber sensors to the structural parts of the Sung-San Bridge, the bridge load test was measured. These smart concrete structure systems can be applied to bridges and the load capacity of the bridge can assessed.

• 방사선산업학회지
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• 제7권2_3호
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• pp.201-207
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• 2013

Soil liquefaction by tsunami or wave induced currents can cause serious damages to coastlines and coastal infrastructures. Although liquefaction caused by regular waves over sea beds has been extensively investigated, studies of tsunami-induced liquefaction near coastal area have been relatively rare. In this work, the hydraulic scale model has been designed and constructed to investigate the variations of wave height and sediment transport by tsunami. The distorted hydraulic scale model based on the Froude similarity was adopted to represent hydrodynamics and sediment transport in a coastal area. The scale model was composed of control box, screw axis, wave paddle and rotating coastal structure.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.424-432
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• 2007

The last twenty-five years have seen dramatic improvements in and widespread use of IT to describe and document the work of the many disciplines involved in construction projects. Iran is a developing country and construction is a basic factor of developing too. Hence, the country needs to a special programming for construction of buildings, structures and infrastructures. Many parts of Iran are located in highly seismic zones and structures must be constructed safe e.g., according to recent seismic codes. In this paper opportunities of IT in construction industry of Iran are investigated in three categories. Pre-construction phase, construction phase and earthquake disaster mitigation are studied. Studies show that information technology can be used in these items for reducing the losses and increasing the benefits. Both government and private sectors must contribute to this strategic project for obtaining the best result.

• 한국건설관리학회논문집
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• 제18권2호
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• pp.81-90
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• 2017

임진강 유역은 1996년부터 1999년까지 3번의 대규모 홍수가 발생하여 많은 인명피해와 9천억원의 재산피해를 입었다. 우리나라는 기후변화로 인하여 홍수피해가 앞으로 증가할 것으로 예상된다. 본 연구는 기후시나리오를 활용하여 미래의 홍수피해를 예측하고, 실물옵션 기반 경제성분석 방법을 제시하였으며, 임진강유역의 홍수방지시설물 투자사업의 사례연구를 통해 경제성분석을 실시하였다. RCP (Representative Concentration Pathway) 기후시나리오에서 모의된 강수량 자료를 활용하여 홍수피해액을 계산하고, 홍수방지시설물 투자에 의한 저감이익을 분석하였다. 향후 RCP8.5와 RCP4.5 기후시나리오가 실현되는 조건을 가정하여 홍수피해 저감이익의 변동성을 구하고, 2071년에 200년 재현주기에 적응하도록 하는 확장을 위한 투자를 할 수 있는 확장옵션을 적용하여 프로젝트의 옵션가치를 구했다. 옵션가치 분석결과, 두 가지 시나리오 하에서 경제성을 확보하고 있음을 확인하였고, RCP8.5 기후시나리오가 실현될 때가 RCP4.5의 경우보다 홍수피해 저감이익이 더 많이 발생하였다. 본 연구는 정부 의사결정권자가 실물옵션분석방법을 활용하여 홍수방재시설물의 경제성분석에 기후변화 불확실성을 고려할 수 있도록 도와줄 것으로 기대되며, 기후시나리오에서 제공하는 강우자료를 활용하여 기후위험요소를 경제적 가치로 정량화하는 방법을 제시하였다.