• Title/Summary/Keyword: reinforcement position

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Stress waves transmission from railway track over geogrid reinforced ballast underlain by clay

  • Fattah, Mohammed Y.;Mahmood, Mahmood R.;Aswad, Mohammed F.
    • Structural Monitoring and Maintenance
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    • v.9 no.1
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    • pp.1-27
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    • 2022
  • Extensive laboratory tests were conducted to investigate the effect of load amplitude, geogrid position, and number of geogrid layers, thickness of ballast layer and clay stiffness on behavior of reinforced ballast layer and induced strains in geogrid. A half full-scale railway was constructed for carrying out the tests, the model consists of two rails 800 mm in length with three wooden sleepers (900 mm × 10 mm × 10 mm). The ballast was overlying 500 mm thickness clay in two states, soft and stiff state. Laboratory tests were conducted to investigate the response of the ballast and the clay layers where the ballast was reinforced by a geogrid. Settlement in ballast and clay, soil pressure and pore water pressure induced in the clay were measured in reinforced and unreinforced ballast cases. It was concluded that the effect of frequency on the settlement ratio is almost constant after 500 cycles. This is due to that the total settlement after 500 cycles, almost reached its peak value, which means that the ballast particles become very close to each other, so the frequency is less effective for high contact particles forces. The average maximum vertical stress and pore water pressure increased with frequency.

Effect of parameters on the tensile behaviour of textile-reinforced concrete composite: A numerical approach

  • Tien M. Tran;Hong X. Vu;Emmanuel Ferrier
    • Advances in concrete construction
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    • v.16 no.2
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    • pp.107-117
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    • 2023
  • Textile-reinforced concrete composite (TRC) is a new alternative material that can satisfy sustainable development needs in the civil engineering field. Its mechanical behaviour and properties have been identified from the experimental works. However, it is necessary for a numerical approach to consider the effect of the parameters on TRC's behaviour with lower analysis duration and cost related to the experiment. This paper presents obtained results of the numerical modelling for TRC composite using the cracking model for the cementitious matrix in TRC. As a result, the TRC composite exhibited a strain-hardening behaviour with the cracking phase characterized by the drops in tensile stress on the stress-strain curve. This model also showed the failure mode by multi-cracking on the TRC specimen surface. Furthermore, the parametric studies showed the effect of several parameters on the TRC tensile behaviour, as the reinforcement ratio, the length and position of the deformation measurement zone, and elevated temperatures. These numerical results were compared with the experiment and showed a remarkable agreement for all cases of this study.

Optimal design of seismic reinforcement for structures with asymmetric rigidity plans using genetic algorithm (유전자 알고리즘을 이용한 비대칭 강성 구조물의 내진보강 최적설계)

  • Lee, Joon-Ho;Kim, Yu-Seong;Sung, Eun-Hee
    • Journal of Korean Association for Spatial Structures
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    • v.24 no.2
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    • pp.65-73
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    • 2024
  • In this study, we propose an optimal design method by applying the Prefabricated Buckling Restrained Brace (PF-BRB) to structures with asymmetrically rigidity plan. As a result of the PF-BRB optimal design of a structure with an asymmetrically rigidity plan, it can be seen that the reduction effect of dynamic response is greater in the case of arrangement considering the asymmetric distribution of stiffness (Asym) than in the case of arrangement in the form of a symmetric distribution (Sym), especially It was confirmed that at an eccentricity rate of 20%, the total amount of reinforced PF-BRBs was also small. As a result of analyzing the dynamic response characteristics according to the change in eccentricity of the asymmetrically rigidity plan, the distribution of the reinforced PF-BRB showed that the larger the eccentricity, the greater the amount of damper distribution around the eccentric position. Additionally, when comparing the analysis models with an eccentricity rate of 20% and an eccentricity rate of 12%, the response reduction ratio of the 20% eccentricity rate was found to be large.

Process Model for 6 Sigma(${\sigma}$) in Construction Management(CM) (건설사업관리(CM)에서의 6시그마(${\sigma}$) 적용 조건 분석을 통한 추진 모델 구축)

  • Kim, Chan-Gyo;Lee, Jea-Sauk;Chun, Jae-Youl
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.478-482
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    • 2006
  • The domestic enterprises in order to secure the freshness location of market from the international competition which is keen are propelling a price and a quality high position strategy steadily. It is put in competitive situation with the overseas enterprises and even from construction industry it follows in construction market opening and there is not another idea to the research the management strategies, directions and focus competitive elements of the enterprise against, what it sees consequently and to rise to the priority where the competitive power reinforcement of the enterprise is important, it becomes. Competitive power of like this enterprise for a reinforcement the technique which induces a big interest 6 Sigma is technique from the many companies. 6 sigma preceding researches of manufacturing and service industry the fact that it is accomplished with the object which will carry most. The research which relates with construction industry is staying to an introduction of 6 sigma the investigation phase, the actual introduction introduces and "S" construction there is not only a possibility against the application result of having a limit because it is applying. It is like that but like referring to a minute description for the international competitive power security which it follows in the change which market environment is sudden 6 sigma the introduction will judge, indispensability development of the logical propriety against hereupon and it will reach and it verifies the question investigation for to lead, 6 sigma of the construction companies it confirms the application possibility and presents the propulsion model as 6 sigma the fact that overcoming the limit characteristic of that introduction application as objective of sample research means it will do.

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A Study on Improvement of Research Ethic System in University (대학 연구윤리체계의 발전방안 연구)

  • Ahn, Sang-Yoon
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.203-211
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    • 2022
  • This study is to examine the causes of research misconduct such as plagiarism, forgery, redundant publication, unfair author expression, and incapacitation of the research ethics system of university researchers and to suggest improvement plan. It basically relied on literature research. In order to supplement the deficiencies in literature research, I sought advice from an expert professor who had experience working in a research-related field in university or who is currently in a position related to research ethics through the delphi-method. As a result of the study, from the perspective of individual researchers, the complacent attitude, dishonesty, and greed for research funds were identified as the main reasons. In terms of organization, it was analyzed for reasons such as lack of detail and application of regulations, lack of verification system, and performance-oriented research environment. In order to overcome research misconduct caused by the researcher's personal reasons, regularization, increase in the number of research ethics education, and strengthening personal penalties were suggested. As a way to overcome irregularities arising from institutional reasons, the reinforcement of the verification system, the reinforcement of the whistle-blower's personal protection system, the omission of promotion, and the quality and quantitative balance of research evaluation was suggested.

Application and its Reinforcing Effect of Soil Nailed-drilled Shafts (쏘일 네일(soil nail)로 보강된 현장타설말뚝의 적용성 및 보강효과 분석)

  • 김병철;이대수;김대홍;정상섬;김대학
    • Journal of the Korean Geotechnical Society
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    • v.20 no.5
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    • pp.87-98
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    • 2004
  • In this study reinforcing effect of soil nailed-drilled shafts subjected to axial and lateral loads was evaluated. Special attention was given to the reinforcing effects of soil nails placed from the drilled shafts to surrounding weathered- and soft-rocks based on model tests, numerical analyses and field tests. The model tests and numerical analyses are conducted to analyze the reinforcing effect of various conditions of number, inclination, position and length. The results of 1/40 scale model tests and numerical analyses show that as the number of reinforcing level increases, the incremental effect of reinforcement tends to increase, whereas the reinforcing effect on relative position is negligible. In addition there is a reinforcing effect as the inclination angle increase up to 30 degrees. Based on the results of tensile load tests, soil nailed-drilled shaft has a considerably smaller settlement to reach the ultimate level compared with the result of un-reinforced drilled shafts. For compression tests, there is a reinforcing effect of about 200% measured.

A Study on the Stability Analysis of Reinforced Embankment on the Soft Ground (연약지반상의 보강성토의 안정해석에 관한 연구)

  • 임종철;전미옥;박이근;정연인
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.285-296
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    • 1999
  • Preloading method is used to prevent the settling of a foundation and to increase the strength of ground by consolidation settlement in advance. But, the embankment used in preloading method brings large deformation and sliding failure in the soft ground. Recently, reinforcement method is often used in embankment in order to prevent sliding failure. But, until now, the research on the stability analysis considering both the rate of strength increase of clay by embankment load and increase of resistance force by the geosynthetics in the embankment body is not found. In this study, the stability analysis program(REAP) for embankment including these two points is developed. By this program(REAP), the stability analysis can be done about during the gradual increase of embankment and the stability counterplan can be established when the safety factor is lower than allowable safety factor of design. After calculating the position of sliding failure surface, the force of geosynthetics which is selected by either the effective tensile strength or tensile force caused by the displacement of soil mass in this position is applied to stability analysis. And the increase of resisting moment can be calculated by this force. Also, the construction period can be estimated and the time for the appropriate counterplan can be decided in order to maintain the stability of embankment. And then, safe and economical embankment design can be performed.

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A Study on the Activation·Specification of 119 Rescue & Care in JeJu (제주도 119구조·구급대의 활성화 및 전문화 방안)

  • Koh, Jae-Moon;Kim, Tae-Min;Kim, Hyo-Sik;Lee, Young-A
    • The Korean Journal of Emergency Medical Services
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    • v.6 no.1
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    • pp.153-168
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    • 2002
  • Since 1992, conventional fire fighting businesses have been converted into a metropolitan autonomous fire fighting system to be ready for a variety of disasters. However, the corresponding investment has been overlapped due to the non-integration of businesses to prevent any potential disasters, and a series of collaborative systems have been not functioning so well. In the meantime, our fire fighting sector has been trying to set up its own clean and faithful position by abolishing any inconvenient system or outsourcing private sectors, and expanded its work scope from conventional fire fighting even to rescue and emergency works. While focusing on handling disaster, the fire fighting sector has been widely trusted and reliable throughtout our nation. Moreover, our fire fighting sector has secured nation wide mobile organizations, technical personnel by field, special equipments and independent communication network. In addition, the fire fighting sector has knowledges, expertise and capabilities required for managing disasters, while in charge of almost every disaster management works including fire, explosion, collapse, disaster and flood. It becomes an organization for comprehensive disaster management under an absolute national trust, which is based on the system for prevention, preparation and countermeasure against a variety of disasters. Thus, our fire fighting sector must make many efforts and try to modernize conventional education and training. The ways to facilitate rescue and emergency works may include the nurture of technical fire fighting personnel along with modernized equipments, the reinforcement of rescue and emergency education, the facilitation of operating civil defense corps, the facilitation of operating volunteer fire fighting corps, the better arrangement of 119 briefing room for public healthcare in provincial offices, the sterilization of rescue instruments and equipments the better repair education for emergency rescue member, the establishment of regional emergency assistant system and the expansion of fire fighting personnel and equipments. In terms of reinforcing the functions and services of rescue 119 and emergency corps, we must review the following considerations: Building up security system along with operational expansion, building up a system for emergency medical treatment, building up a comprehensive information management system for rescue and emergency, constructing a provincial safety museum and so forth. For the ways to better the works of rescue 119 we can review the following considerations : Improving the education for fire fighting training corps under Jeju Provincial Fire and Disaster Management Department, providing rescue members with more opportunities for clinical practices, enhancing the morale of rescue members, installing a comprehensive briefing room for emergency rescue members, building up medical networks along with reasonable policies for information service, operating the consulting system for rescue 119 and so on. If these requirements are met, it is expected that the fire fighting departments in Jeju province can cope with every accident and disaster a little more rapidly and quickly in compliance with local needs, so that they can keep their own position as a public fire fighting organization which may be trusted by the public.

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A study into effect the terminological definition of cultural industry has on creativity of cultural contents - Based on comparative study between Korean Cultural Industry, US Entertainment Industry and UK Creative Industry - (문화산업의 용어적 정의가 문화콘텐츠 창의성에 미치는 영향에 관한 연구 - 한국 문화산업, 미국 엔터테인먼트 산업, 영국 크리에이티브 산업과의 비교를 통하여 -)

  • Yoo, Jun-Ho;Yoon, Sung-Gum
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.5 no.1
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    • pp.1-18
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    • 2010
  • Cultural industry along with cultural content that forms the center of cultural industry is the field whose interest is continually increasing due to the increase of weight in the national economy and the strengthening of importance in future value. Cultural content, particularly, accounts for the essential position in starting a business around one-person business, which recently arouses high interest in a nation. However, it is true that the debates on the rapid growth and identity of cultural content in contrast to the reinforcement of its position, and the criticisms about the lack in development of material and cultural content in staring a business show the limitation of overall cultural content in Korea. This research examines recognition of cultural industry or cultural content through terminologies of definition as well as the relationships of configures in accordance with the outcome of cultural content. Findings demonstrate that cultural content in Korea revealed the highest cultural orientation which is the same as existing interpretations, and as comparison objects, entertainment industry in the U.S. and creative industry in the UK contained the highest part of entertainment and creativity respectively. It reflects that mythical elements of language that has been discussed from the structuralist perspectives are projected in the relevant field. In conclusion, the conceptual definition of cultural content has the structure to project advantages and disadvantages of existing culture, and this limitation needs to be overcome in securing the items and business value in starting a business.

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Effect of the Size and Location of a Web Opening on the Shear Behavior of High-Strength Reinforced Concrete Deep Beams (고강도 철근콘크리트 깊은 보의 전단거동에 대한 개구부 크기 및 위치의 영향)

  • Yang, Keun-Hyeok;Eun, Hee-Chang;Chung, Heon-Soo
    • Journal of the Korea Concrete Institute
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    • v.15 no.5
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    • pp.697-704
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    • 2003
  • The purpose of this experimental study is to investigate the relationship of the shear behavior and the variety of width, depth and location of an opening in reinforced concrete deep beams with rectangular web openings, and to present an improved shear strength equation of those members. The main parameters considered were concrete strength(fck), shear span-to-overall depth ratio(a/h), and the size and vortical position of the web openings. Twenty five deep beams were tested under two symmetric loading-points. Test results showed that the shear behavior of deep beams with web openings was influenced by a/h and the size of opening. In addition, the KCI shear design provision is a tendency to be more unconservative according to the increase in a/h and the area-ratio of opening to shear span(Ao/Ash). Based on the concrete strut action of top and bottom member of an opening and the tie action of longitudinal reinforcement, a proper design equation which closely predicts the capacity of deep beams with rectangular openings is developed.