• Title, Summary, Keyword: 근입비

Search Result 10, Processing Time 0.034 seconds

Study on Pullout Behavior of Pipe Anchor (파이프형 앵커의 인발거동에 대한 연구)

  • Bae, Wooseok;Lee, Bongjik;Kwon, Youngcheul;Lee, Jundae
    • Journal of the Korean Geoenvironmental Society
    • /
    • v.9 no.1
    • /
    • pp.5-10
    • /
    • 2008
  • In this study, laboratory model test was performed to estimate pullout behavior of pipe type anchor with surface roughness, embedment and diameter. The design of buried pipe anchors in areas of vertical ground movement is governed, in part, by magnitude of the forces imposed on the pipe and displacements at which they are developed. In this paper, uplift resistance and displacement characteristics of pipe anchors caused by ground condition and embedment ratio, surface roughness, pipe diameter through the analysis of pipe anchor model test were compared and analyzed. The test results of the buried pipe showed that as the relative density increases, ultimate uplift resistance increase in 20%. When pipe anchor is failed with the relative density of the ground, the change of surface roughness, it was shown that the deformation increases as the ratio of penetration increases from 2 to 8 in five times approximately. And most anchor-based theories overestimate the breakout factor.

  • PDF

Numerical Analysis of Peak Uplift Resistance of Buried Pipeline in Sand and Soft Clay (연약 점토와 사질토에 묻힌 파이프라인의 극한 인발저항력 산정)

  • Kwon, Dae-Hean;Seo, Young-Kyo
    • Journal of Ocean Engineering and Technology
    • /
    • v.31 no.3
    • /
    • pp.227-232
    • /
    • 2017
  • Subsea pipelines are one of the most important structures used to transport fluids such as oil and natural gas in offshore environments. The uplift behavior of the pipeline caused by earthquakes and buoyancy can result in a pipeline failure. The objective of this study is to examine the peak uplift resistance through parametric studies with numerical modeling by PLAXIS 3D Tunnel. The effects of the embedment ratio and pipe diameter were first examined for uplift resistance in sand and soft clay conditions. Then the length of geogrid layers and the number of geogrid layers were examined in terms of ability to resist uplift behavior.

Failure Characteristics of Foundation System Reinforced with Stone Columns (쇄석말뚝으로 보강된 기초시스템의 파괴 거동)

  • Shin, Bang Woong;Bae, Woo Seok
    • Journal of the Korean Geoenvironmental Society
    • /
    • v.2 no.3
    • /
    • pp.71-80
    • /
    • 2001
  • The quantitative analysis of bearing capacity with stone column-mat is not ease because the bearing capacity of stone column is affected by so many parameters. The bearing capacity of stone column is mainly governed by horizontal resistance along the interface with soil. Also, this foundation system is affected by geometric factors such as column spacing, embedment ratio and failure surface inclination. Therefore, in this study, critical length and the effect of failure surface inclination was studied with single and group end bearing stone columns by loading tests. Results of model tests are compared to the present theoretical methods and are examined with FEM analysis.

  • PDF

Basic Design of Subsea Manifold Suction Bucket (심해저 원유 생산용 매니폴드 기초 석션 버켓 기본 설계)

  • Woor, Sun-Hong;Lee, Kangsu;Choung, Joonmo
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.55 no.2
    • /
    • pp.161-168
    • /
    • 2018
  • This paper presents the design procedure of the suction bucket used to support a subsea manifold. The soil-suction bucket interaction numerical analysis technique was verified by comparing the present results with a reference data. In order to simulate the soil-bucket interaction analyses of a subsea manifold structure, various material data such as undrained shear strength, elastic modulus, and poisson ratio of soft clay in Gulf of Mexico were collected from reference survey. We proposed vertical and horizontal design loads based on system weights and current-induced drag forces. Under the assumption that diameter of the suction bucket was 3.0 m considering real dimension of the subsea manifold frame structures, aspect ratio was decided to be 3.0 based on reference survey. The ultimate bearing load components were determined using tangent intersection method. It was proved that the two design load components were less than ultimate bearing loads.

Effect of Embedment Ratio and Loading Rate on Uplift Adhesion Factor of Concrete Driven Pile (근입비와 인발속도가 콘크리트 항타말뚝의 인발부착계수에 미치는 영향)

  • Kim Jong-In;Park Jeong-Jun;Shin Eun-Chul
    • Journal of the Korean Society for Railway
    • /
    • v.8 no.4
    • /
    • pp.367-371
    • /
    • 2005
  • Pile foundations are utilized when soil is so weak that shallow foundations are not suitable or point load is concentrated in small area. Such soil can be formed by the land reclamation works which have extensively been executed along the coastal line of southern and western parts of the Korean Peninsula. The working load at pile is sometimes subjected to not only compression load but also lateral load sad uplift forces. But in most of the practice design, uplift capacity of pile foundation is not considered and estimation of uplift capacity is presumed on the compression skin friction. This study was carried out to determine that the effect of embedment ratio and loading rate on uplift adhesion factor of concrete pile driven in clay. Based on the test results, the critical embedment ratio is about 9. Adhesion factor is constant under the critical embedment ratio, and decreasing over the critical embedment ratio. Also, adhesion factor is increased with the loading rate is increased.

Vibration Characteristics of Tapered Piles Embedded in an Elastic Medium (탄성매체에 근입된 변단면 말뚝의 진동 특성)

  • Oh, Sang-Jin;Kang, Hee-Jong;Lee, Jae-Young;Park, Kwang-Kyou;Mo, Jeong-Man
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.832-835
    • /
    • 2005
  • The free vibration of tapered piles embedded in soil is investigated. The pile model is based on the Bernoulli-Euler beam theory and the soil is idealized as a Winkler model for mathematical simplicity. The governing differential equations for the free vibrations of such members are solved numerically. The square tapered piles with one free and the other hinged end with rotational spring are applied in numerical examples. The lowest two natural frequencies are obtained over a range of non-dimensional system parameters: the rotational spring parameter, the embedded ratio, the foundation parameter, the width ratio of the contact area and the section ratio.

  • PDF

Analysis of Ultimate Capacity of Plate Anchor on Loading Rate Capacity in Clay (점토 지반에서 인발속도에 따른 판앵커의 극한 인발저항력 분석)

  • Seo, Young-Kyo;Ryu, Dong-Man
    • Journal of Ocean Engineering and Technology
    • /
    • v.27 no.3
    • /
    • pp.15-21
    • /
    • 2013
  • Anchors are primarily designed and constructed to resist outwardly directed loads imposed on the foundation of a structure. These outwardly directed loads are transmitted to the soil at a greater depth by the anchors. Buried anchors have been used for thousands of years to stabilize structures. Various types of earth anchors are now used for the uplift resistance of transmission towers, utility poles, submerged pipelines, and tunnels. Anchors are also used for the tieback resistance of earth-retaining structures, waterfront structures, at bends in pressure pipelines, and when it is necessary to control thermal stress. In this research, we analyzed the uplift behavior of plate anchors in clay using a laboratory experiment to estimate the uplift behavior of plate anchors under various conditions. To achieve the research purpose, the uplift resistance and displacement characteristics of plate anchors caused by the embedment ratio, plate diameter, and loading rate were studied, compared, and analyzed for various cases.

Characteristics of Load-Settlement Behaviour for Embeded Piles Using Load-Transfer Mechanism (하중전이기법을 이용한 매입말뚝의 하중-침하 거동특성)

  • Oh, Se Wook
    • Journal of the Korean Geoenvironmental Society
    • /
    • v.2 no.4
    • /
    • pp.51-61
    • /
    • 2001
  • A series of model tests and analyses by load transfer function were performed to study load-settlement behaviour with relative compaction ratio of soil and embeded depth of pile. In the model tests, embeded depth ratio(L/D) of pile were installed 15, 20, 25 and relative compaction of soil(RC) is 85%, 95% and then cement were injected at around perimeter of pile. For analysis of embedded pile, the paper were compared results of model tests with analysis results by Vijayvergiya model and Castelli model, Gwizdala model of elastic plasticity-perfect plastic model and then the fitness load transfer mechanism was proposed to predict load-settlement behaviour of embeded pile. The analysis results of predicted bearing capacity by load transfer function, ultimate bearing capacity of embeded pile were approached to measured value and behaviour of initial load-settlement curve were estimated that load transfer function by Castelli were similar to measured value. The result of axial load analysis of bored pile shows that skin friction estimated by load transfer mechanism is investigated more a little than that of measured values.

  • PDF

Deformation Characteristics of Steel Plate Cellular Bulkhead (강판셀 호안의 변형특성)

  • Jeong Wook Kang
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.9 no.4
    • /
    • pp.165-175
    • /
    • 1997
  • This study qualitatively reviewed effect of the height of loading and the ratio of penetration on. the characteristics of deformation of cellular bulkhead by performing a model test of embedded steel plate cellular bulkhead which had different loading height and penetration ratio. And we also examined the effect of the loading height upon the shear behavior by performing two-dimensional model test making use of aluminum rods for a filler. Besides, test results and theoretical values based on Hansen's earth pressure theory were compared and reviewed. In consequence, it was ascertained that the yield moment of cells depended on the height of loading and the ratio of penetration, and the slip surface was located on the lower area of a cell interior according as the height of loading becomes lower. The theoretical consideration which was based on the theory of earth pressure proposed by Hansen revealed that the test results accorded with the theoretical values to some degree, and the same results were derived about the location change of the slip surface.

  • PDF

The Effect of Wall Friction on Deformation Characteristics of the Cellular Bulkhead (Cell 구조물의 변형특성에 미치는 셀 벽면 마찰의 영향)

  • Son, Dae-San;Jang, Jeong-Wook;Kim, Kyong-Yeol;Kim, Hyun-Guk;Chung, Youn-In
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.22 no.4
    • /
    • pp.230-234
    • /
    • 2010
  • This study examined the effect of wall friction on deformation characteristics of the cellular bulkhead, in terms of artificial wall friction based on the results of model tests according to the existing penetration ratio and loading height. 1. The effect of wall friction on deformation characteristics of the cellular bulkhead turned out to be less as the loading height decreases and the penetration ratio increases. The yield load also becomes less as wall friction decreases. 2. The ratio of the rotational displacement to the horizontal displacement of the cellular bulkhead becomes less as the loading height decreases and the penetration ratio increases. Hence it is concluded that the effect of wall friction has close relationship with the rotational displacement.