• Structural Engineering and Mechanics
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• 제47권4호
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• pp.575-598
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• 2013

The study presents the results of an experimental program concerning the shear force transfer between reinforced concrete (RC) jackets and existing columns with damages. In order to investigate the effectiveness of the repair method applied and the contribution of each shear transfer mechanism of the interface. It includes 22 concrete columns (core) (of 24,37MPa concrete strength) with square section (150mm side, 500 mm height and scale 1:2). Ten columns had initial construction damages and twelve were subjected to initial axial load. Sixteen columns have full jacketing at all four faces with 80mm thickness (of 31,7MPa concrete strength) and contain longitudinal bars (of 500MPa nominal strength) and closed stirrups spaced at 25mm, 50mm or 100mm (of 220MPa nominal strength). Fourteen of them contain dowels at the interface between old and new concrete. All columns were subjected to repeated (pseudo-seismic) axial compression with increasing deformation cycles up to failure with or without jacketing. Two load patterns were selected to examine the difference of the behavior of columns. The effects of the initial damages, of the reinforcement of the interface (dowels) and of the confinement generated by the stirrups are investigated through axial- deformation (slip) diagrams and the energy absorbed diagrams. The results indicate that the initial damages affect the total behavior of the column and the capacity of the interface to shear mechanisms and to slip: a) the maximum bearing load of old column is decreased affecting at the same time the loading capacity of the jacketed element, b) suitable repair of initially damaged specimens increases the capacity of the jacketed column to transfer load through the interface.

• Smart Structures and Systems
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• 제14권3호
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• pp.479-499
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• 2014

This paper illustrates the damages of reinforced concrete and masonry minarets during October 23 (Erciş) and November 9 (Edremit), 2011 Van earthquakes in Turkey. Erciş and Edremit are townships located 90km and 18km from Van city center in Turkey, respectively. Ground accelerations and response spectrums for these earthquakes are given in this paper. A total of 63 reinforced concrete and masonry minarets are heavily damaged or collapsed in the city center and villages nearby after both earthquakes. Because of the fact that there is no Turkish standard and specification directly related to design of minarets, nearly all of the constructions are carried out by workers using only their own technical knowledge. So, all of the non-engineering reinforced concrete and masonry minarets completely collapsed or damaged heavily. From the study, it is seen that the damages are due to several reasons such as site effect, location, and length of the fault, reduction in cross section and formation of the discontinuity, use of plain reinforcement steel, use of concrete with insufficient strength, existence of short lap splices and incorrect end hook angle, larger mass and stiffness concentrations on some region, longitudinal reinforcements discontinuity, cracks at the cylindrical body, and damage of spire and end ornament. In addition to these reasons, the two earthquakes hit the minarets within seventeen days, causing progressive damage. So, the existing design and construction practices should be improved to provide sufficient earthquake performance. Also, it is recommended that there should be a safe distance between the minaret and surrounding structures to reduce the loose of life after earthquake.

• 한국건설관리학회논문집
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• 제24권2호
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• pp.50-58
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• 2023

입찰담합은 공공건설공사에서 빈번히 발생하는 문제로, 관련 당국에서는 적절한 제재가 필요하다. 본 연구는 민사적 측면과 형사적 측면을 모두 고려하여 입찰담합을 차단하기 위한 최적의 집행모델의 필요성을 분석하였다. 최근에는 공정거래위원회에서 과징금을 부과하고 발주처에서 민사상 손해배상 소송을 제기하는 등 공정거래법상 제재가 중첩되는 경우가 발생하고 있다. 본 연구의 목적은 건설공사 입찰담합에 대한 중복제재 가능성에 대한 과징금 및 보상체계의 실효성을 평가하는 것이다. 공정거래법상 중복제재가 제도개선에 도움이 된다는 결과를 얻었다. 다만 국가가 원고인 손해배상 소송에서는 과징금 및 형량 등을 고려해야 하며, 공동행위에 대한 과징금을 감면하고, 확정판결 후 과징금을 환급하며, 과징금 부과 시 손해배상 제도 등을 고려할 필요가 있다. 본 연구는 제재 및 보상의 개선 효과를 분석하여 공공건설공사의 입찰담합을 억제하기 위한 효율적인 집행모델 개발에 기여한다.

• 환경정책연구
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• 제10권3호
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• pp.3-20
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• 2011

태양광 및 풍력단지 건설 운영 사례에서 나타나는 환경 사회적 갈등들을 통하여 그 원인을 분석하고, 국내외의 긍정적인 건설 운영 및 갈등 조정 사례들을 분석하여 갈등의 최소화 방안 및 제도적 보완책을 모색하였다. 국내 태양광 및 풍력단지의 건설 운영 사례에서 나타나는 갈등은 지역 환경 훼손, 발전 시설에 따른 직접적인 피해, 발전 사업에 따른 지역 이익의 부재, 환경규제 및 관리상의 문제가 주된 원인이며, 이의 해결을 위한 방안으로 발전 사업 지침 개선 및 강화, 주민 수용성 확보, 사업설명회 규정 강화, 이해당사자의 참여 확대 방안 및 대안 입지와 해상풍력의 조속한 시행을 제시하였다. 이들 방법을 통해 신재생에너지기본계획 중 태양광 및 풍력에너지의 목표, 환경의 보호 및 보전 그리고 주민수용성 향상을 달성할 수 있다.

• 화약ㆍ발파
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• 제30권1호
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• pp.37-51
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• 2012

본 시공사례는 "성남~여주 복선전철 제${\bigcirc}$공구 노반건설공사"로서 터널의 노선을 따라 진동 및 소음으로 인한 피해영향권내에 주요 보안물건이 위치하고 있다. 설계단계에서 이러한 피해영향을 고려하여 기계식 암파쇄 굴착공법이 적용되어 있으나, 합리적인 공사기간 단축을 위한 대안 터널굴착공법이 요구되어 당 현장의 발파진동 허용기준(우사:0.09cm/sec, 주택 0.2cm/sec)을 준수하면서 시공성 및 경제성을 높일 수 있는 전자발파공법이 검토되었다. 이에, 최근 활성화 되고 있는 터널용 전자발파시스템(eDev)을 활용한 현장 시험시공을 통한 환경영향평가를 실시한 결과, 발파공해에 대한 안정적인 관리가 가능한 것으로 판단되었으며, 이를 기초로 한 시공결과 근접 보안물건에 대한 피해영향 없이 높은 굴진효율성을 보였다.

• Structural Engineering and Mechanics
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• 제67권6호
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• pp.579-585
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• 2018

Masonry walls are of a complex (anisotropic) structure in terms of their mechanical properties. The mechanical properties of the walls are affected by the properties of the materials used in wall construction, joint thickness and the type of masonry bond. The carried-out studies, particularly in the seismic zones, have revealed that the most of the conventional masonry walls were constructed without considering any engineering approach. Along with that, large-scale damages were detected on such structural elements after major earthquake(s), and such damages were commonly occurred at the brick-joint interfaces. The aim of this study was to investigate the effect of joint thickness and also type of mortar on the mechanical behavior of the masonry walls. For this aim, the brick masonry walls were constructed through examination of both the literature and the conventional masonry walls. In the construction process, a single-type of brick was combined with two different types of mortar: cement mortar and hydraulic lime mortar. Three different joint thicknesses were used for each mortar type; thus, a total of six masonry walls were constructed in the laboratory. The mechanical properties of brick and mortars, and also of the constructed walls were determined. As a conclusion, it can be stated that the failure mechanism of the brick masonry walls differed due to the mechanical properties of the mortars. The use of bed joint thickness not less than 20 mm is recommended in construction of conventional masonry walls in order to maintain the act of brick in conjunction with mortar under load.

• Structural Engineering and Mechanics
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• 제85권2호
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• pp.197-206
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• 2023

The deterioration caused by chloride penetration and carbonation plays a significant role in a concrete structure in a marine environment. The chloride corrosion in some marine concrete structures is invisible but can be dangerous in a sudden collapse. Therefore, as a novelty, this research investigates the ability of a non-destructive damage detection method named the Power Spectral Density (PSD) to diagnose damages caused only by chloride ions in concrete structures. Furthermore, the accuracy of this method in estimating the amount of annual damage caused by chloride in various parts and positions exposed to seawater was investigated. For this purpose, the RC Arosa bridge in Spain, which connects the island to the mainland via seawater, was numerically modeled and analyzed. As the first step, each element's bridge position was calculated, along with the chloride corrosion percentage in the reinforcements. The next step predicted the existence, location, and timing of damage to the entire concrete part of the bridge based on the amount of rebar corrosion each year. The PSD method was used to monitor the annual loss of reinforcement cross-section area, changes in dynamic characteristics such as stiffness and mass, and each year of the bridge structure's life using sensitivity equations and the linear least squares algorithm. This study showed that using different approaches to the PSD method based on rebar chloride corrosion and assuming 10% errors in software analysis can help predict the location and almost exact amount of damage zones over time.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.219-223
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• 1995

Since the mid of 1970's, the construction of infrastructure has been booming and accelerating to keep up with rapid economic growth. Fast achievement of most construction activities has caused unfavorable effects of civil petitions associated with damages and nuisances due to last hasty works. it is well known that the falling down of Sungsoo bridge and the collapse of Sampoong department and other structures have occurred because of the construction not conforming with the specification, and thereby incurred enormous loss of life and property. Now a days. a periodic inspection and maintenance have been strongly interested on aged RC structures, of repair and reinforcement technique in the country, most repairing and reinforcing works have been performed on the basis of the guidance of few experienced local company in this field.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.493-502
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• 2020

Traditionally, road projects are initiated based on an assessment of their economic benefit, after which the environmental, social and governance effects are addressed discretely for the project according to a set of predetermined alternatives. Sustainable road infrastructure planning is vital as issues like diminishing access to road construction supplies, water scarcity, Greenhouse Gas emissions, road-related fatalities and congestion pricing etc., have imposed severe economic, social, and environmental damages to the society. In the process of addressing these sustainability factors in the operational phase of the project, the dynamics of these factors are generally ignored. This paper argues that effective delivery of sustainable roads should consider such dynamics and highlights how different aspects of sustainability have the potential to affect project sustainability. The paper initially presents the different sustainability-assessment tools that have been developed to determine the sustainability performance of road projects and discuss the inability of these tools to model the interrelationships among sustainability-related factors. The paper then argues the need for a new assessment framework that facilitates modelling these dynamics at the macro-level (system level) and helping policymakers for sustainable infrastructure planning through evaluating regulatory policies.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.638-641
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• 2004

본 연구에서는 기존의 철거개념과는 달리 건설폐기물의 발생량을 최소화하고 자원의 재활용률을 높이기 위한 최적의 분별해체 관리시스템을 제시하고자 한다. 본 시스템은 해체량의 산정에서부터 각 구조부위별 해체방법, 발생된 자원의 활용계획 등을 사전에 계획하고 운영하게 함으로서 국가 전체 건설폐기물의 발생량을 저하시킴으로서 환경부하량을 최소화하는데 큰 기여를 하는 것을 목적으로 한다. 본 시스템의 구성은 크게 해체사전조사계획, 해체물량산정, 해체공사계획, 폐기물관리계획의 4개 모듈로 구성되어 있고, 이 모듈은 사용자의 사용 목적에 따라 모듈별로 사용하는 것이 가능하다.