• Title/Summary/Keyword: Design of piles

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Approximate seismic displacement capacity of piles in marine oil terminals

  • Goel, Rakesh K.
    • Earthquakes and Structures
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    • v.1 no.1
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    • pp.129-146
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    • 2010
  • This paper proposes an approximate procedure to estimate seismic displacement capacity - defined as yield displacement times the displacement ductility - of piles in marine oil terminals. It is shown that the displacement ductility of piles is relatively insensitive to most of the pile parameters within ranges typically applicable to most piles in marine oil terminals. Based on parametric studies, lower bound values of the displacement ductility of two types of piles commonly used in marine oil terminals - reinforced-concrete and hollow-steel - with either pin connection or full-moment-connection to the deck for two seismic design levels - Level 1 or Level 2 - and for two locations of the hinging in the pile - near the deck or below the ground - are proposed. The lower bound values of the displacement ductility are determined such that the material strain limits specified in the Marine Oil Terminal Engineering and Maintenance Standard (MOTEMS) are satisfied at each design level. The simplified procedure presented in this paper is intended to be used for preliminary design of piles or as a check on the results from the detailed nonlinear static pushover analysis procedure, with material strain control, specified in the MOTEMS.

The Use of Piles to Cut Slopes Design in Cohesive Soils (억지말뚝을 이용한 점성토지반 절토사면의 설계)

  • 홍원표;한중근;송영석
    • Journal of the Korean Geotechnical Society
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    • v.15 no.5
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    • pp.157-170
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    • 1999
  • A new design technique is presented to stabilize cut slopes in cohesive soils by use of piles. The design method can consider systematically factors such as the gradient and height of slope, the number and position of pile's rows, the interval and stiffness of piles, etc. The design method is established on the basis of the stability analysis of slope with rows of piles. The basic concept applied in the stability analysis is that the soil across the open space between piles can be retained by the arching action of the soil, when a row of piles is installed in soil undergoing lateral movement such as landslides. To obtain the whole stability of slope containing piles, two kinds of analyses for the pile-stability and the slope- stability must be performed simultaneously. An instrumentation system has been installed at a cut slope in cohesive soil, which has been designed according to the presented design process. The behavior of both the piles and the soil across the open space between piles is observed precisely. The result of instrumentation shows that the cut slope has been stabilized by the contribution of stabilizing effect of piles on the slope stability in cohesive soil.

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Development of Design Method of Disconnected Piled Raft Foundation System (기초분리말뚝 공법의 설계기법 개발)

  • Choi, Jung-In;Min, Ki-Hoon;Kim, Sung-Ho;Kwon, Oh-Sung;Kim, Myoung-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.691-699
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    • 2008
  • In the design of a foundation, settlement of the foundation may exceed allowable design criteria even with a competent bearing stratum. In such a case, a piled-raft foundation system may be adopted using piles as settlement reducing component. In this paper, Disconnected Piled Raft Foundation (DPRF) system, which installs disconnected piles underneath the raft and uses the piles as ground reinforcements, is studied as a cost effective design method against the classical piled-raft foundation system. To this end, large size loading tests were carried out on weathered ground changing area replacement ratio and length of piles. The results indicated that the settlement of the reinforced ground was reduced by 34~87% and the allowable bearing pressure increased by 70% on average from those of the unreinforced original ground, respectively. The correlating formula between the area replacement ratio and the load bearing ratio of piles were derived from the test results and numerical analysis. From the correlation, a design method determining the size and the quantity of the disconnected piles to enhance the bearing capacity of original ground to the desired value was proposed based on one inch settlement criteria.

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Analysis and design of inclined piles used to prevent downhill creep of unsaturated clay formations

  • Poorooshasb, H.B.;Miura, N.;Noorzad, Ali
    • Structural Engineering and Mechanics
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    • v.6 no.3
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    • pp.245-257
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    • 1998
  • This paper present an analysis which may be used to obtain a rational design of a system of inclined piles used in preventing downhill creep of unsaturated clay formations. It uses two simple and relatively easy to measure parameters (an estimate of the maximum downhill creep together with a knowledge of the depth of the so called active zone) to calculate the required section size and the optimal spacing (pitch) of the piles for a desired efficiency of the system as a whole. Design charts are provided to facilitate the process.

The Bending and the Bearing Capacity of Bonding Method of Steel Piles into Pile Caps (강관말뚝 두부보강 방법의 휨내력 및 압축내력 특성)

  • 오성남;유제남;홍성영
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.389-396
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    • 2002
  • Engineers should be careful in the design of bonding piles into pile caps because they are weak points in the pile foundation. Therefore in this study, the mechanism of bonding piles into pile caps was explained, and the design method of the composite bonding method was proposed. And the proposed design method was verified in comparison with the result of the full scale test. Also, the characteristic for the bearing capacity and the mechanism of compressive load of bonding method were analyzed.

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Simplified method to design laterally loaded piles with optimum shape and length

  • Fenu, Luigi;Briseghella, Bruno;Marano, Giuseppe Carlo
    • Structural Engineering and Mechanics
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    • v.71 no.2
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    • pp.119-129
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    • 2019
  • Optimum shape and length of laterally loaded piles can be obtained with different optimization techniques. In particular, the Fully Stress Design method (FSD) is an optimality condition that allows to obtain the optimum shape of the pile, while the optimum length can be obtained through a transversality condition at the pile lower end. Using this technique, the structure is analysed by finite elements and shaped through the FSD method by contemporarily checking that the transversality condition is satisfied. In this paper it is noted that laterally loaded piles with optimum shape and length have some peculiar characteristics, depending on the type of cross-section, that allow to design them with simple calculations without using finite element analysis. Some examples illustrating the proposed simplified design method of laterally loaded piles with optimum shape and length are introduced.

A Case Study on the Design and Drivability Criteria of Steel Pile in Offshore (해상 강관말뚝의 설계 및 항타시공관리 사례연구)

  • Song, Myung-Jun;Park, Yung-Ho;Yoo, Seok-Jun;Sim, Dong-Hyun
    • 기술발표회
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    • s.2006
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    • pp.75-85
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    • 2006
  • The project comprised the construction of the new oil pier and associated topside facilities and demolition of exiting south pier. The site is located approximately 33km south of Kuwait city at MAA refinery. The approach trestle and berth structures of the new oil pier were designed to be supported by steel tubular piles Total 2,480 numbers of piles(795 piles at Approach Trestle, 1187 piles at Berth 1 -4 and 498 piles at Berth 5-6) had to be driven through the calcareous silty sand In this study, the design procedures for offshore steel pipe piles, evaluation for the compression and tension capacities by static and dynamic load test and effective driving criteria by the final set values are discussed

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A Design Method of Earth-Retaining Structure Constructed by a Row of Bored Piles in Cohesive Soils (점성토지반속 주열식 흙막이벽의 설계법)

  • Hong, Won-Pyo;Gwon, U-Yong;Go, Jeong-Sang
    • Geotechnical Engineering
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    • v.5 no.3
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    • pp.29-38
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    • 1989
  • A design method is presented for the earth-retaining structure ccnslructtd by a row of bored Piles, which has such merits as low-vibration and low-noire during construction. And utility of the design method is investigated by performing a design example. First, theoretical rquations to estimate the resisting force of a row of earth-retaining was in cohesive soils are estabilished for grounds above and below bottom of excavation, reprctively. The characteristics of soils and the effect pile's interval can be considered logically in the theoretical equations. Then, the method for stability.analysis is presented for the earth-retaining piles by applying the theoretical equation of resisting forces on a row of piles. Finally, the design of earth-retaining piles is performed within the ranges which can satisfy the stabilities of both piles and soils. On investigation cf the sail-stability, the stability for bottom heave In cohesive soils is also investigated.

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Case Studies of Several Load Tests for Large Diameter Battered Steel Pipe Piles Constructed on the Offshore Area. (대구경 해상 강관말뚝의 설계지지력 확인을 위한 여러 가지 재하시험의 적용)

  • 이정학;서덕동;정헌주
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.291-298
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    • 2001
  • It is very difficult to accomplish load tests of piles with large diameter constructed on the offshore area, because of requirement for large scaled loading equipment and bad testing conditions. Therefore, so far in many cases pile driving dynamic formulas have applied to quality control, and recently dynamic load test method is widely used for confirming bearing capacities of such piles. However, in cases of piles with very large diameter about 2,500mm, it is nearly impossible for regular type load test methods of piles such as static and dynamic to apply owing to very large design load. This is case studies of load tests such as modified static and dynamic load tests of piles and point load tests of rock samples for estimating rational allowable bearing capacity of very large diameter piles constructed on the marine area.

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Design Practice of Transverse Spiral Reinforcement of Piles in Accordance with AASHTO LRFD Bridge Design Specification

  • Kim Yeong Seon;Song Jong Young;Park Kyoung Lae;Choi In Ki;Yang Byung Hong;Flett Innes D.
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.221-224
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    • 2005
  • The purpose of this study is to introduce design practice for transverse reinforcement in piles where the top of the pile is free-standing above the ground in accordance with AASHTO LRFD Design Specification. Based on the relevant requirements, the amount and spacing of transverse spiral reinforcement is given for the two different pile types, namely piles with pile cap and pile bents. In addition, a recommended design procedure is introduced depending on the predicted behaviour of the piles from the analysis.

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