• 제목/요약/키워드: existing foundation

검색결과 725건 처리시간 0.023초

등가유효폭을 가진 원형기초해석법을 이용한 풍력발전기 말뚝기초의 연직하중에 대한 층상암반 해석 (Analysis of Stratified Rock under Vertical Load in Pile Foundation of Wind Turbine Using Circular Foundation Analysis Method with Equivalent Effective Width)

  • 김도한;박상렬;문경태
    • 대한토목학회논문집
    • /
    • 제33권6호
    • /
    • pp.2411-2425
    • /
    • 2013
  • 퇴적층과 암반층이 층상구조로 되어있는 지반의 층상암반층 위에 말뚝기초를 설계할 경우, 연직하중에 대한 지지암반의 파괴모드(휨파괴, 펀칭전단파괴 혹은 선단지지파괴)를 검토하고 지지력을 계산하기 위해서는 층상지지암반층의 구조해석이 필요하다. 그러나 ACI committee 436과 우리나라 구조물기초설계기준에서 제안하고 있는 기존의 이용 가능한 탄성평판해석법(Elastic Plate Analysis Method)은 매우 복잡하여 기술자가 이용하는데 어려움이 많다. 따라서 본 연구에서는 복잡한 탄성평판해석법 대신 비교적 간단한 원형기초해석법(Circular Foundation Analysis Method)을 이용할 수 있도록 등가유효폭(반경)의 개념과 식을 제시하였고, 이를 통하여 탄성평판해석에 의한 모멘트와 전단력이 원형평판해석의 결과와 같도록 관계식을 제안하였다. 그 결과 등가유효폭을 이용한 원형기초해석의 방법은 매우 단순하고 편리하였고, 제안된 방법에 의한 결과를 탄성평판해석과 유한요소해석 결과와 비교한 결과 매우 잘 일치하였다.

극지환경을 고려한 선체보강판 구조의 최종강도 평가 (Ultimate Strength Assessment of Ship Stiffened Panel under Arctic Conditions)

  • 김양섭;박대겸;김상진;이동훈;김봉주;하연철;서정관;백점기
    • 대한조선학회논문집
    • /
    • 제51권4호
    • /
    • pp.283-290
    • /
    • 2014
  • Environmental changes, especially global climate change, are creating new routes to reduce a shipping service distance in Arctic area. The Arctic routes are shorter than 60% of existing ways Panama or Suez canal). For this reason, ship owners prefer to navigate in Arctic area and a transportation of goods though the Arctic area is increasing. But the low temperature in Arctic condition changes the material properties. Especially, the material will be brittle and strength will increase. And an ultimate strength analysis of ship stiffened panels is changed depending on temperatures. In present study, the ultimate strength analysis of stiffened panels in double hull oil tankers is performed under various low temperatures with the material properties obtained by tensile coupon test. The analytical method as named ALPS/ULSAP was used for analysis method and 6 kinds of temperature (20, 0, -20, -40, -60 and $-80^{\circ}C$) were considered to investigate the effect of Arctic conditions.

Analytical modeling of bending and free vibration of thick advanced composite beams resting on Winkler-Pasternak elastic foundation

  • Chami, Khaldoune;Messafer, Tahar;Hadji, Lazreg
    • Earthquakes and Structures
    • /
    • 제19권2호
    • /
    • pp.91-101
    • /
    • 2020
  • This work presents an efficient and original hyperbolic shear deformation theory for the bending and dynamic behavior of functionally graded (FG) beams resting on Winkler - Pasternak foundations. The theory accounts for hyperbolic distribution of the transverse shear strains and satisfies the zero traction boundary conditions on the surfaces of the beam without using shear correction factors. Based on the present theory, the equations of motion are derived from Hamilton's principle. Navier type analytical solutions are obtained for the bending and vibration problems. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions. It can be concluded that the present theory is not only accurate but also simple in predicting the bending and vibration behavior of functionally graded beams.

Analytical solutions for geosynthetic tube resting on rigid foundation

  • Guo, Wei;Chu, Jian;Yan, Shuwang;Nie, Wen
    • Geomechanics and Engineering
    • /
    • 제6권1호
    • /
    • pp.65-77
    • /
    • 2014
  • Geosynthetic tubes inflated with water, clay slurry or sand have been widely used for large dike construction in land reclamation projects. In this paper, analytical solutions for geosynthetic tube resting on rigid foundation is presented by adopting an approach similar to that presented by Leshchinsky et al. (1996). The proposed method allows a quick preliminary design to be made for using a closed-form solution. To simplify the analysis, relationships between geometrical parameters and pumping pressure are established using numerical method. The analytical solutions were compared with several existing solutions and good agreements were achieved.

Deformation analysis of a geocell mattress using a decoupled iterative method

  • Zhang, Ling;Zhao, Minghua;Zhao, Heng
    • Structural Engineering and Mechanics
    • /
    • 제46권6호
    • /
    • pp.775-790
    • /
    • 2013
  • Deformation analysis is a major concern in many geotechnical applications. In this paper, the deformation behavior of a geocell mattress subjected to symmetric loads was studied. The mattress was idealized as an elastic foundation beam. The horizontal beam-soil interfacial shear resistances at the beam top and bottom sides were taken into account by assuming the resistances to be linear with the relative horizontal displacements. A decoupled iterative method was employed to solve the differential displacement equations derived from the force analysis of a beam element and to obtain the solutions for the deformations and internal forces of the geocell reinforcement. The validity of the present solutions was verified by the existing finite element method and power-series solutions.

Development of a Predictive Model for Cement Stabilised Roadbase

  • Chai Gray W.;Oh Erwin Y.;Smith Warren
    • 한국도로학회논문집
    • /
    • 제8권2호
    • /
    • pp.31-35
    • /
    • 2006
  • Cement stabilisation is a common method for stabilising recycled road base material and provides a longer pavement life. With cement effect, the increment of stiffness in the stabilised layer would provide better load transfer to the pavement foundation. The recycling method provides an environmentally option as the existing road base materials will not be removed. This paper presents a case study of a trial section along the North-South Expressway in West Malaysia, where the Falling Weight Deflectometer (FWD) was implemented to evaluate the compressive strength and in-situ stiffness of the cement stabilised road base material. The improvement in stiffness of the cement stabilised base layer was monitored, and samples were tested during the trial. FWD was found to be useful for the structural assessment of the cement-stabilised base layer prior to placement of asphalt layers. Results from the FWD were applied to verify the assumed design parameters for the pavement. Using the FWD, an empirical correlation between the deflection and the stiffness modulus of the pavement foundation is proposed.

  • PDF

농촌건강장수마을사업 평가지수 산정방안 연구 (A Study of a Scoring Method for Evaluating the Project of Rural Well-longevity Villages)

  • 서교;한이철;이정재
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 2005년도 학술발표논문집
    • /
    • pp.436-442
    • /
    • 2005
  • The purpose of this study is to develop indices and a scoring method for effectively evaluating the project of rural well-longevity villages which makes up for insufficient parts of existing projects on improving settlement foundation and production environment. Evaluating indices include qualitative factors originated from the characteristics of the project so a scoring method based on an information measure technique is used for evaluating the results from each village. Evaluating indices are provided differently depending on each purpose for evaluation. Result indices can be used for ranking project villages and fundamental indices can be used to analyze villages elaborately to improve project plans.

  • PDF

Transport and the Megacity: Improving Vitality with Connectivity

  • Prevc, John
    • 국제초고층학회논문집
    • /
    • 제6권2호
    • /
    • pp.131-138
    • /
    • 2017
  • There is no easy answer to ensuring the world's rapid urban population growth is managed sustainably and in a manner that promotes economic growth, social cohesion, and health and wellbeing. However, densification of existing urban areas is increasingly recognised as an effective and socially responsible way for cities to accommodate growing populations and still operate as vital, vibrant spaces. The Future Spaces Foundation's Vital Cities: Transport Systems Scorecard explores how well-networked, safe and sustainable transport networks equip densifying cities to meet the needs of their rising and fast-changing populations. This paper uses data from the scorecard to examine the transport infrastructure and associated data networks of three large, rapidly densifying cities - Beijing, Mumbai and $S{\tilde{a}}o$ Paulo - and highlight the successful measures and policies implemented between them. It includes an in-depth explanation of the scorecard's methodology, and concludes with an appeal for people-focused transport design that values safety, urban vibrancy and individual wellbeing over corporate efficiency.

PRD시공시 H-PILE 대체 자재로 원가절감 할수 있는 공법 사례 (Downward Method of H-PILE Alternative Materials of Percusion Rotary Drill)

  • 이왕희;이일재;임시내
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
    • /
    • pp.199-202
    • /
    • 2014
  • In recent years the downtown, Top-down method has been applied in a major method to solve the complaints due to noise, vibration, dust and safety issues such as cracking due to settlement when the excavation close to the building. Until it is installed underground permanent foundation, the Pre-founded Column is a pile foundation as well as a column to bear the upper construction load. The Pre-founded Column is constructed by PRD method generally. The EnP(Enlarging Pile) method can be expanded locally boring diameter of the embedment zone as compared to the PRD method existing general. Since the bearing capacity is increased by the boring diameter is expanded, the embedment length is reduced, the construction cost is reduced.

  • PDF

직사각형 재하판을 이용한 평판재하시험에 의한 지반의 합성탄성계수 추정에 관한 연구 (The evaluation of complex elastic modulus of the foundation by the rectangular plate loading test)

  • 강차훈;조현영;정진환;김성도
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
    • /
    • pp.166-173
    • /
    • 2000
  • This paper describes the method of evaluating the elastic modulus of soil medium by using the Retangular Plate Loading Test. The foundaton is considered to be the elastic half-space. The stiffness matrix of elastic half space is drived using Boussinesq's analytical soulution. A numerical examples are presented to verify the validity of this procedure. Also, the numerical results are compared with those of the existing study results. The procedure proposed in this theses can be applied to the design of concrete paving resting on the elastic foundation

  • PDF