• Title/Summary/Keyword: code provisions

Search Result 295, Processing Time 0.031 seconds

Axial behavior of CFRP wrapped RC columns of different shapes with constant slenderness ratio

  • Narule, Giridhar N.;Bambole, Abhay N.
    • Structural Engineering and Mechanics
    • /
    • v.65 no.6
    • /
    • pp.679-687
    • /
    • 2018
  • In composite materials technology, the fiber-reinforced polymers (FRP) have opened up new horizons in infrastructural engineering field for strengthening existing structures and components of structure. The Carbon fiber reinforced polymer (CFRP) sheets are well suited for RC columns to this application because of their high strength to weight ratio, good fatigue properties and excellent resistance to corrosion. The main focus of present experimental work is to investigate effect of shapes on axial behavior of CFRP wrapped RC columns having same cross-sectional area and slenderness ratio. The CFRP volumetric ratio and percentage of steel are also adopted constant for all the test specimens. A total of 18 RC columns with slenderness ratio four were cast. Nine columns were control and the rest of nine columns were strengthened with one layer of CFRP wrap having 35 mm of corner radius. Columns confined with CFRP wrap were designed using IS: 456:2000 and ACI 440.2R.08 provisions. All the test specimens were loaded for axial compression up to failure and failure pattern for each shaped column was investigated. All the experimental results were compared with analytical values calculated as per the ACI-440.2R-08 code. The test results clearly demonstrated that the axial behavior of CFRP confined RC columns is affected with the change in shapes. The axial deformation is higher in CFRP wrapped RC circular column as compared to square and rectangular columns. Stress-strain behaviour revealed that the yield strength gained from CFRP confinement was significant for circular columns as compare to square and rectangular columns. This behaviour may be credited due to effect of shape on lateral deformation in case of CFRP wrapped circular columns at effective confinement action.

Reliability of analytical models for the prediction of out-of-plane capacity of masonry infills

  • Pasca, Monica;Liberatore, Laura;Masiani, Renato
    • Structural Engineering and Mechanics
    • /
    • v.64 no.6
    • /
    • pp.765-781
    • /
    • 2017
  • The out-of-plane response of infill walls has recently gained a growing attention and has been recognised fundamental in the damage assessment of reinforced concrete and steel framed buildings subjected to seismic loads. The observation of damage after earthquakes highlighted that out-of-plane collapse of masonry infills may occur even during seismic events of low or moderate intensity, causing both casualty risks and unfavourable situations affecting the overall structural response. Even though studies concerning the out-of-plane behaviour of infills are not as many as those focused on the in-plane response, in the last decades, a substantial number of researches have been carried out on the out-of-plane behaviour of infills. In this study, the out-of-plane response is investigated considering different aspects. First, damages observed after past earthquakes are examined, with the aim of identifying the main parameters involved and the most critical configurations. Secondly, the response recorded in about 150 experimental tests is deeply examined, focusing on the influence of geometrical characteristics, boundary conditions, prior in-plane damage, presence of reinforcing elements and openings. Finally, different theoretical capacity models and code provisions are discussed and compared, giving specific attention to those based on the arching theory. The reliability of some of these models is herein tested with reference to experimental results. The comparison between analytically predicted and experimental values allows to appreciate the extent of approximation of such methods.

The Scope of Potential Duties for Environment Protection in the Regulation on the Exploitation for Polymetalic Nodules in the Area (심해저 망간단괴 생산규칙의 잠재적 환경보호 의무 범위에 관한 연구)

  • Kim, Jung-Eun;Park, Seong-Wook
    • Ocean and Polar Research
    • /
    • v.37 no.1
    • /
    • pp.81-90
    • /
    • 2015
  • International Seabed Authority (ISA) is currently developing rules with regard to exploitation of manganese nodules which will be contained in its first regulations governing the exploitation of deep seabed mineral resources. A stakeholder survey was conducted in the early 2014 by ISA with the aim of facilitating participation of interested entities in the development process of the rules. The stakeholders who had replied to the survey included existing contractors, sponsoring States, environmentalists, academics, and nongovernmental organizations. Opinions given by them largely reflect their own interests. This paper aims to clarify the scope of the obligations regarding the environmental protection which may be imposed on contractors under the new regulations for the exploitation of manganese nodules. To do so, it first analyses the express provisions on environmental protection applicable to deep seabed mining included in the Law of the Sea Convention, its agreement on implementation of Part XI, and the regulations on exploration for manganese nodules. Secondly, it categorizes these obligations based on the categories of international obligations suggested by Combacau and Alland. Based on the categorizations this paper concludes that, in addition to the existing duties to protect deep seabed environment within the Law of the Sea Convention system, the following new obligations could be added: conservation of exploitation sites for a limited time after the contract is ceased; taking all necessary measures for rehabilitation of destroyed ecosystems that occurredas a result of mining activities; monitoring exploitation sites for a limited period time after the contract is ceased; observing rules and standards on safety of ships and environmental protection adopted under IMO instruments; regulation on the discharge of mine tailings from the facilities used for exploitation of deep sea minerals. Lastly, this paper attempts to provide ways of reflecting national interests in terms of potential obligations which may be included in the new regulations.

Arbitration as a Means to Replace Shareholder Class Action (주주집단소송의 대체수단으로서의 중재)

  • 김연호
    • Journal of Arbitration Studies
    • /
    • v.11 no.1
    • /
    • pp.75-93
    • /
    • 2001
  • The advantages of arbitration such as promptness, economy and flexibility apply to the disputes arising from corporate governance between shareholders and a corporation. The confidentiality of arbitration can be particularly highlighted in the disputes among the members inside corporation. But it appears that the shareholders believe litigation the best way to pursue liabilities of managers of corporation and improve the system of corporate governance. And it is claimed that the current litigation system lacks the implementation of shareholders rights due to structural deficiency and therefore need bring class actions into the system of Korean jurisprudence. The OECD, which afforded the rescue finances to Korea, also recommended shareholder class actions as a way to improve corporate governance. Class actions have merits but even advanced countries consider the changes of existing system or only stay class actions in the stage of discussion. Rather, legal experts urge arbitration to be used more frequently and the Courts also approved the dispute resolutions of the disputes as to corporate governance through arbitration. There is no report in Korea that arbitration was used to resolve the disputes between shareholders and the managers, or between shareholders and corporation, which is listed in the Stock Market. There only are the debates for bring class actions into the judicial system between NGOs and the organizations of corporate managers. But arbitration has greater advantages in resolving the disputes among the members of corporation that any other methods for dispute resolution. Arbitration can interpret flexibly the mandatory provisions of the Statutes of Security and the Code of Commerce to meet the needs of parties involved, which is not possible to the Courts. Arbitration can issue the award to meet the equity of the parties. And arbitration can avoid a resolution of All or Nothing by fully considering the specific situations of Korean corporations(such as family-dominated management) and can issue the award beneficial to all parties of shareholders, managers and corporation. Thus it should be sought to resolve the disputes as to corporate governance through arbitration.

  • PDF

An Analysis of the Shear Strength of Reinforced Concrete Beams with Recycled Coarse Aggregates (순환굵은골재 철근 콘크리트 보의 전단강도 분석)

  • Ji, Sang-Kyu;Yun, Hyun-Do;Song, Seon-Hwa;Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.11a
    • /
    • pp.851-854
    • /
    • 2008
  • Using the recycled aggregate not only saves landfill space but also reduces the demand for extraction of natural raw material for new construction activity. However few investigations have been carried out to study the shear behaviors of RC beams with recycled aggregates such as low absorption of recycled aggregate and full-scale specimens. In this study, six reinforced concrete beams were tested to evaluate the effects of shear strength, and shear behavior on the replacement level (0, 30, 60, and 100%) of recycled coarse aggregate and different amounts of shear reinforcement. The results showed that the beams with recycled coarse aggregates present the similar shear strength and deflections as the beam with natural aggregate on an equal amount of shear reinforcement. the reinforced concrete beams with recycled coarse aggregates present the Influence of shear span-to-depth ratio, effective depth, tension reinforcement ratio and compressive strength as the beams with natural aggregate. Shear strength were compared with the provisions in current code (KCI2007) and the equation proposed by Zsutty. The KCI equations were conservative and subsequently can be used for the shear design of recycled aggregate concrete beam.

  • PDF

Application features of The detailed rules of Census (1896) through the change of house Kan numbers in Gyeonpyeong-bang, Jung-seo in Hanseong-bu -Focused on Gyeonpyeong-bang 1-tong to 23-tong in 1903 and 1906- (한성부 중서 견평방에서 가택 칸수의 변화를 통해서 살펴본 「호구조사세칙」(1896)의 적용 양상 -1903년과 1906년의 견평방 1통에서 23통까지를 대상으로-)

  • Cho, Yun-O;Woo, Don-Son
    • Journal of architectural history
    • /
    • v.28 no.6
    • /
    • pp.19-30
    • /
    • 2019
  • This study explores the application aspect of The detailed rules of Census (1896) through the change of Kan numbers in Gyeonpyeong-bang. Although Gyeonpyeong-bang was a high-priority area because of its location, it was difficult to trace the operation of the urban situation due to lack of data. This study is focusing on restoring space and society in the Gyeonpyeong-bang using the information on the type of houses and the number of Kan listed in the family register of Hanseong-bu. The detailed rules of Census sets out provisions for the family registry and the rules of making Tong. Especially when it comes to the rules of making Tong, this rule deals with the code of making ten Hos into one Tong. This study was conducted by dividing the status of the Tong into three types: uncompleted Tong, exceeded Tong without vacant Ho number, and exceeded Tong with the vacant Ho number. Since these three types of Tong are in the process of change towards the complete Tong with 10 Hos, they were thought to be able to demonstrate the specific application of the rules. This study will be meaningful as a case study that expands the point of existing research on the Tong making rules, which was not focused relatively on restoring urban conditions at that time, by looking at the changes in exceptions that deviated from the Sipgajaktong rule.

Rocking behavior of bridge piers with spread footings under cyclic loading and earthquake excitation

  • Hung, Hsiao-Hui;Liu, Kuang-Yen;Chang, Kuo-Chun
    • Earthquakes and Structures
    • /
    • v.7 no.6
    • /
    • pp.1001-1024
    • /
    • 2014
  • The size of spread footings was found to be unnecessarily large from some actual engineering practices constructed in Taiwan, due to the strict design provisions related to footing uplift. According to the earlier design code in Taiwan, the footing uplift involving separation of footing from subsoil was permitted to be only up to one-half of the foundation base area, as the applied moment reaches the value of plastic moment capacity of the column. The reason for this provision was that rocking of spread footings was not a favorable mechanism. However, recent research has indicated that rocking itself may not be detrimental to seismic performance and, in fact, may act as a form of seismic isolation mechanism. In order to clarify the effects of the relative strength between column and foundation on the rocking behavior of a column, six circular reinforced concrete (RC) columns were designed and constructed and a series of rocking experiments were performed. During the tests, columns rested on a rubber pad to allow rocking to take place. Experimental variables included the dimensions of the footings, the strength and ductility capacity of the columns and the intensity of the applied earthquake. Experimental data for the six circular RC columns subjected to quasi-static and pseudo-dynamic loading are presented. Results of each cyclic loading test are compared against the benchmark test with fixed-base conditions. By comparing the experimental responses of the specimens with different design details, a key parameter of rocking behavior related to footing size and column strength is identified. For a properly designed column with the parameter higher than 1, the beneficial effects of rocking in reducing ductility and the strength demand of columns is verified.

Comparison on Flexural Behaviors of Architectural Precast Prestressed Rectangular and Inverted-tee Concrete Beams (건축용 프리캐스트 프리스트레스트 역티형 보와 직사각형 보의 휨거동 비교)

  • 유승룡
    • Journal of the Korea Concrete Institute
    • /
    • v.12 no.6
    • /
    • pp.75-82
    • /
    • 2000
  • Flexural behaviors of two typical architectural precast beam sections ; inverted tee and rectangular - were compared and investigated. The heights of web in inverted tee beams are generally less than half of beam depth in building structures to accomodate the nib of double-tee where the total building height limited considerably. The inverted-tee beams are designed for parking live load - 500kgf/$\m^2$ and market - 1,200kgf/$\m^2$ according to the currently used typical shape in the domestic market building site in Korea. The bottom dimension and area of rectangular beams are same to those of inverted tee beams to compare the flexural behaviors of two beams. These two beams are also reinforced for similar strength. Four flexural tests are performed on two beams. Following results are obtained from the tests; 1) The rectangular beam is simpler in production, transportation, and election, and more economic than the inverted tee beam for these two beams with same dimension and similar strength. 1) The estimations of flexural strength of two beams by Strength Design Method and Strain Compatibility Method is fully complied with the result of tests. However, Strain Compatibility Method is slightly ore accurate than Strength Design Method. 2) Overall deflections of two type beam under the service loads are less than those of the allowable limit in ACI Code provision. 3) The rectangular beam is failed in large deflection (average 12.56mm large) than those of inverted tee beams. 4) The rectangular and inverted tee beams with 6m span develop initial flexural crackings under the 88% of full service loading even though they designed to satisfy the ACI tensile stress limit provisions.

An Overview of the ADR Act of 2004 in the Philippines - Focused on the Adoption of the UNCITRAL Model Law - (필리핀의 2004년 대체적 분쟁해결법 소고 - UNCITRAL 모범법의 수용과 관련하여 -)

  • Kim, Sun-Jeong
    • Journal of Arbitration Studies
    • /
    • v.19 no.2
    • /
    • pp.197-227
    • /
    • 2009
  • This study describe the brief history and current statutes of Philippine arbitration. The practice of arbitration in the Philippines can be traced as far back as the barangay. From 1521, Spanish Civil Code became effective in the Philippines. During this period, the Supreme court was discouraged by the tendency of some courts to nullify arbitration clauses on the ground that the clauses ousted the judiciary of its jurisdiction. According to the growing need for a law regulating arbitration in general was acknowledged when Republic Act No.876(1953), otherwise known as the Arbitration Law, was passed. In 1958, the Philippines became a signatory to the New York Convention and in 1967 the said Convention was ratified. But no legislation has been passed. As a consequence, foreign arbitral awards have sometimes been deemed only presumptively valid, rather than conclusively valid. Fifty years after, the Philippine Congress enacted, Republic Act No. 9285, otherwise know as the Alternative Dispute Resolution Act of 2004. The enactment was the Philippines solution to making arbitration an efficient and effective method specially for international arbitration. To keep pace with the developments in international trade, ADR Act of 2004 also ensured that international commercial arbitration would be governed by the UNCITRAL Model Law on International Arbitration and also fortified the use and purpose of the New York Convention by specifically mandating. If the international commercial arbitration will be revitalization in the near future in the Philippine, it will be shown that the model law's comprehensive provisions will give the beat framework for arbitration.. The writer expect that Philippines continues in its effort to be the premier site for international arbitration in Southeast Asia.

  • PDF

Confinement models for high strength short square and rectangular concrete-filled steel tubular columns

  • Aslani, Farhad;Uy, Brian;Wang, Ziwen;Patel, Vipul
    • Steel and Composite Structures
    • /
    • v.22 no.5
    • /
    • pp.937-974
    • /
    • 2016
  • While extensive efforts have been made in the past to develop finite element models (FEMs) for concrete-filled steel tubular columns (CFSTCs), these models may not be suitable to be used in some cases, especially in view of the utilisation of high strength steel and high strength concrete. A method is presented herein to predict the complete stress-strain curve of concrete subjected to tri-axial compressive stresses caused by axial load coupled with lateral pressure due to the confinement action in square and rectangular CFSTCs with normal and high strength materials. To evaluate the lateral pressure exerted on the concrete in square and rectangular shaped columns, an accurately developed FEM which incorporates the effects of initial local imperfections and residual stresses using the commercial program ABAQUS is adopted. Subsequently, an extensive parametric study is conducted herein to propose an empirical equation for the maximum average lateral pressure, which depends on the material and geometric properties of the columns. The analysis parameters include the concrete compressive strength ($f^{\prime}_c=20-110N/mm^2$), steel yield strength ($f_y=220-850N/mm^2$), width-to-thickness (B/t) ratios in the range of 15-52, as well as the length-to-width (L/B) ratios in the range of 2-4. The predictions of the behaviour, ultimate axial strengths, and failure modes are compared with the available experimental results to verify the accuracy of the models developed. Furthermore, a design model is proposed for short square and rectangular CFSTCs. Additionally, comparisons with the prediction of axial load capacity by using the proposed design model, Australian Standard and Eurocode 4 code provisions for box composite columns are carried out.