• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.3
• /
• pp.92-98
• /
• 2012

This study shows details of a specific space truss frame structure devised to carry out maintenance and repair temporary works in tunnels. The purpose of this study is to verify structural safety and function of the innovative truss structure through an analysis tool, i.e.. ABAQUS, which is a suite of software application for finite element analysis and computer aided engineering. And then optimized size, i.e., thickness and diameter of truss members is evaluated in practice. In this study, construction methods in the temporary works are additionally represented by using the new space truss frame structure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.3
• /
• pp.169-175
• /
• 2022

Korea's construction industry has a shortage and aging of construction manpower, low productivity compared to other industries, and a high rate of industrial accidents. The Ministry of Land, Infrastructure and Transport is preparing for the 4th industrial revolution and is expanding investment in construction automation and innovative growth engines to improve productivity in the construction industry. In order for new technologies to be utilized in the road construction field, the accuracy of the technologies and the applicability of each type of work must be evaluated. In this study, the accuracy of the mobile mapping system was tried to verify based on the relevant work regulations, and to suggest the applicability of the mobile mapping system to high-speed driving tracks through data acquisition and analysis on road construction sites. The accuracy of the equipment used in the study was verified in accordance with the relevant work regulations, and the possibility of applying the mobile mapping system used for the study to road construction surveying was presented with a maximum error of less than 10cm in the horizontal and vertical directions. In addition, the possibility of utilizing the road construction survey using the mobile mapping system was presented through comparison with the existing method for data acquisition time for construction surveying, production of construction status survey results, and calculation of heatmap and earthworks. In the future, the use of construction status surveying of the mobile mapping system will greatly improve the efficiency of construction work.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.765-773
• /
• 2022

This study is a study on the application of a horizontal excavation machine system to improve constructability. In this study, the structural stability of non-covered temporary facilities was evaluated by comparing field measurements and numerical analysis. In addition, the appropriateness of the measurement results was analyzed by comparing and analyzing the results of numerical analysis with the analysis results applying the Gaussian probability density function to the measurement results. In this study, structural safety and long-term durability of the linkage were analyzed based on numerical analysis. As a result of the study, it was analyzed that the non-open cut method (H.A.S. method) of this study secures structural safety and constructability as the behavior in the actual construction process is more safe than the numerical analysis results, even if the uncertainty of the ground condition is taken into account.

• Journal of Korean Society of Forest Science
• /
• v.109 no.4
• /
• pp.446-453
• /
• 2020

By applying the Analytic Hierarchy Process(AHP) method, we calculated the weight of factors related to the selection of check dam sites and generated basic data related to the selection of the target site. As a result of the AHP classification, three evaluation items(Susceptibility, Vulnerability, and Constructability), 12 evaluation factors (Susceptibility 10, Vulnerability, and Constructability 1), and two-six evaluation criteria in each evaluation factor were selected. After calculating the relative importance by using the selected evaluation items, evaluation factors, and criteria, the vulnerability items such as medical facilities, facilities for the aged, educational facilities, and private homes were found to be higher than the other items. When the relative weight for deciding qualified sites was applied to the forest watersheds in the Gangwon region, 8,601 forest watersheds(35.2 % of the total forest watersheds) were found to be suitable for the installation of check dams.

• Journal of the Korean Geosynthetics Society
• /
• v.13 no.4
• /
• pp.11-20
• /
• 2014

The behaviors and stability of reinforced subgrade with short geogrid were examined and evaluated during construction. First of all, analytical approach for the minimum length of geogrid was performed to guarantee stability during construction loading state. Secondly, the economic aspects for reinforced subgrade were compared with between domestic standards applying with 0.7 H reinforcement length and new way to mix short and long reinforcement. Full scale railroad subgrade was constructed with the size of 5 m high, 6m wide, and 20m long to verify the stability of the subgrade with the length of 0.3 H, 0.35 H, 0.4 H reinforcement. Total 51 sensors were installed to measure settlement, bulging, and the change of stress of the subgrade. It is concluded that the reinforced subgrade with short(0.35H, 35% of height) geogrid had stability within allowable level of deformation and stress increment during construction.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.2
• /
• pp.78-83
• /
• 2012

Steel fiber reinforced shotcrete in tunneling construction has some problems in terms of constructability, durability and lots of rebound wastage. In order to resolve these problems, this pater proposes polyamide fiber reinforced shotcrete technology. And this paper presents the results of experimental construction of the polyamide fiber reinforced shotcrete technology. The results of the study are as follows. 1. The polyamide fiber reinforced shotcrete suggested in this paper shows outstanding mechanical performance that meets various Korean tunnel construction design criteria. 2. In addition, the results of experimental constructions show that the polyamide fiber reinforced shotcrete creates less rebound and wasted product than the steel fiber reinforced shotcrete. Based on the above results, it is concluded that the polyamide fiber reinforced shotcrete technology can be used as economical and environmentally friendly construction of tunnel.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.84-84
• /
• 2009

파이프라인을 건설함에 있어 가장 중요한 기술이 배관 용접기술이다. 즉 파이프와 파이프를 연결하는 작업이 공사 진척도를 결정하기 때문에, 이를 얼마나 경제적으로 신속하게 수행해 나가느냐하는 것은 건설기간 및 건설비용을 결정하는 핵심 요소이다. 가스배관 시공 원주용접 방법은 여러 가지 있는데, 현재 국내에서는 전량 수동용접을 채택하고 있다. 이 방법은 국내 가스배관을 건설한 초기부터 적용해온 것으로 우수한 품질을 확보할 수 있으며, 취약한 국내 자동화기술과 열악한 도로 매설 시공여건에서 적용하기 용이한 방안이다. 그러나 우수한 용접기량을 보유한 용접사가 점차 부족해지고, 배관시공 시간을 단축하고 비용을 줄이기 위한 필요성이 점차 커지면서 이를 해결할 수 있는 기술로서 자동원주용접방안이 있다. 이 기술들은 해외 가스배관에 이미 오래전부터 적용되어 용접부위 신뢰성과 품질 우수성을 확보하고 시공비용절감을 달성하고 있다. 자동용접을 적용하기 위해서는 용접절차를 수립하여 절차인증시험을 수행하고, 기존방안과 동일이상의 품질이 확보되며 효율성을 겸비해야만 한다. 국가 기본에너지의 안정적인 공급을 위해 적기 시공이 필요하고, 1 km당 10 억원 이상이 소요되는 배관시공비용 중 약 1/3이 용접비파괴검사 비용인 점을 감안할 때 품질이 확보되면서 경제적인 시공방안이 있다면 이를 적용하는 것이 국가 산업 경제적 측면에서 필요한 일이다. 이와 관련된 연구에서는 국내 가스배관 원주용접에 적용 가능한 용접공정을 검토하고, 용접절차를 수립하여 절차인증시험을 수행하였으며, 추가로 배관 원주 자동용접부위에 대한 기계적 특성 평가를 실시하였다. 현재 국내 건설여건과 비파괴검사 기준을 만족시키고 안전성과 효율성을 겸비한 방법으로는 초층과 2층은 수동 GTAW를 적용하고 나머지 층은 반자동 FCAW를 적용하는 방안이 적절한 것으로 판단된다. 전 층을 자동 GTAW로 용접하는 방안은 품질은 확보되지만 효율성측면에서 대형배관에는 적용하기 어려울 것으로 보이며, 해외에서 많이 사용되는 자동 GMAW 방안은 국내 비파괴검사기준을 만족시키기 어려워 검토대상에서 제외하였다. 본 논문에서는 두 가지 용접방법에 대한 용접공정개발과정과 원주용접부위 기계적 특성을 검토하여 최적방안을 제시하고자 한다.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.3
• /
• pp.285-293
• /
• 2023

In this research, we embarked on a meticulous analysis of the challenges inherent in real-world scenarios relating to the durability design standards of engineered concrete structures and the assessment of carbonation durability in concrete guidelines. Our investigation brought to light substantial issues concerning constructability and quality assurance. The genesis of these problems is the exclusive application of prescribed strength to exterior walls, neglecting other elements to facilitate smoother licensing procedures. While this methodology aims to mitigate financial constraints in alignment with enhanced standards, it invariably invites complications. Furthermore, it is imperative to resolve the uncertainty surrounding durability evaluations by establishing a clear and definitive objective. Alongside this, actionable steps must be formulated to forestall the emergence of fissures between the floors of residential buildings, particularly apartment complexes. It is equally essential to tackle issues connected to application by devising a comprehensive management strategy for potential cracking during the phase of maintenance.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.11
• /
• pp.13-18
• /
• 2022

In this study, the suitability of the grouting method will be evaluated by analyzing seismic reinforcement methods for the stability of gravity structure in Port. The evaluation categories are liquefaction, sliding, toppling and circular failure. To compare the appropriateness of the seismic reinforcement method, the low mobility mortar injection, one of the grouting method and the SPC file and GRB method, which are pile wall type reinforcement methods, were evaluated and compared respectively. The object of the evaluation is the gravitational structure of Po-Hang old port. As a result of the evaluation, both the grouting method and the pile wall type reinforcement method are considered to have sufficient stability. Therefore, in the case of the gravity structure, the grouting method is more efficient than the seismic reinforcement method considering construction efficiency, economic efficiency, maintenance and similar construction cases.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.57-60
• /
• 2008

Maglev is a system that a train runs levitated above a rail. Therefore it is very important to maintain a constant levitation gap for achieving serviceability and ride comfort. This study is a cooperation research subject of the 3-1 subject, performance improvement of maglev track structures, of the Center for Urban Maglev Program in Korea, started in 2006. The aim of this study is development of rapid constructions of bridge superstructure for maglev. At present, precast deck is widely used because of its superiority to cast-in-place concrete on quality and the term of works. The research group suggested basic systems of maglev guideway with PSC-U type and trapezoidal open steel box type girder, and precast deck, cooperating with Korea Railroad Research Institute, the managing institute of the 3-1 subject. In this study, a mock-up consisted of girders, decks and rail was fabricated and test was performed for constructability, serviceability and maintenance evaluation of PSC U-type girder, precast deck, and new guide rail system.