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  • 8/17/2019 Piotr Krawczyk - Article

    1/17

     

    OP 

    1.

    2.

    2013

    M

    RoZh

    Hans

    bstract

    This papespans onpredictingscour trenspan analobtained a

    It is demorenches

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    This workevolution.

    ith thesusceptibl

    Keywords

    IntroducPipelines lis caused

    seabed evhese ph

    applicationcurrentsenvironme

    This papeseabed scBBL pipelshelteringanalysis t

     

    Ma

     

    naging

    Piotrmke Bijkeiwen CheBoersma,

    r presentthe BBLspan evolches. Botsis methond unnec

    strated hnd the sg acceptae cases,

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    : pipeline,

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    olution irr nomenas, like theay resul

    ntal loads.

    r consideour. The dine. Theeffect ofchniques

    naging Fre

     

    Free S

    rawczyk,, Wittevee, BMT Ar BBL Com

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  • 8/17/2019 Piotr Krawczyk - Article

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    3.

    2013

    hen co

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  • 8/17/2019 Piotr Krawczyk - Article

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    F105 met

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  • 8/17/2019 Piotr Krawczyk - Article

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    Figure

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  • 8/17/2019 Piotr Krawczyk - Article

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    Figure 3pipeline. Brecordedshows a50% of thpipe diamshelteringrepresentof these s

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    our trence a schemcho Soutly asym

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    ed for thu trench pent. Figurofile sheltely 60%p scour th profileBL pipeli

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  • 8/17/2019 Piotr Krawczyk - Article

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    Practice.

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    F

    Fig

     

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    the back

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    Figure 6simulationdiameter).

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    ponse modeep scouine VIV r re only

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    Fig

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     65% OD

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    Tabl

    Scenari

    Response→ 

    Span Le(L/D

    46

    51

    55

    59

    Span Le

    (L/D46

    51

    55

    59

    The resultlength L/Dratio of 59This is modiameter).

    scour trenlocated inould no

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    Span Evcceptabil

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    Several stincluding

    Ma

     

    1: The e

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     Model

    gth ↓ )

    gth ↓ 

    )

    s present= 59, as lis long e

    re than thThe pipe

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    olutionity of pipewhich arech is ade.g.: glaci

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    ationary ss the critin and th

    sessmentpredictio

    udies havansen et

    naging Fre

     

    fect of scpan overt seabed

    NV-RP-F105

    horizo

    6.0 yr

    0.6 yr

    0.1 yr

    0.0 yr

    7,175 yr

    57.3 yr

    6.9 yr

    2.4 yr

    ed in Tabnger scoough to d scour tr can ther 

    self-remeep trench,stitute anfore ceas

    line freedevelopeuate for t

    er scars,

    h are ge

    ans on aality of the prevailimust ther s into its f 

    e been cal (1991),

    Spans on

    Page 9

    our trencSpan in a mtrench, shelt

    DNV-RP-F105

    Fatigue ental directio

    6.1 yr

    0.6 yr

    0.1 yr

    0.0 yr

    Fatigue e

    vertical100,000+ yr 

    4,990 yr

    347 yr

    93 yr

    le 1 arer spans ar evelop vench depthfore be e

    iate theshelterinobstacle t

    e and nat

    pans is g assuminhe spansboulders,

    erally les

    ynamic s free spag enviro

    efore accuture deve

    rried outKlomp et

    ynamic Se

     

    on spanoderate scoering 50%

    BBL

    stimate for t (in-line VIV

    2,699 y

    872 yr 

    305 yr 

    98 yr

    stimate for t

    irection (cr 100,000+

    89,919 y

    1,830 y

    124 yr 

    truncatede not likeltical sag(typicallypected t

    pan. As t circa 80o the seaural back

    enerally a stationar caused bor rocky

    dynamic

    abed, ho is stronglmental cunt for: (lopment.

    in the paal (1995),

    abed

    Febr 

     fatigue prD

    Spantrench,

    DNV-F10

    e free span+ Direct Wa

      6.1

    0.6

    0.1

    0.0

    e free span

    ss-flow VIV)yr 100,00

    r 9,818

      654

    174

    at non-di to occur.f circa 0.betweentouch th

    e pipelin  of the-water floilling of th

    ssessedspan con

      large, peoutcrops),

      (i.e.: les

    ever, thelinked to

    nditions.) the hist

    t on freeChen & B

    uary 28, 201

    ediction in a deep ssheltering 6

    P- 

    B

    ↓ ve Action)

    r 5,4

    r 1,7

    r 57

    r 18

    ↓ 

    + yr 100,

     yr 100,

    r 100,

    r 13,

    ensional A span wi pipe dia.4 and 0.  bottom

    would nipe diam. The sc

    e trench

    sing guidfiguration.rsistent s  or in ca

      suscepti

    situation ithe persis

     A realistiory of the

    span evolijker (2001

    3

    our% OD

    BL

    8 yr

    00 yr

    8 yr

    8 yr

    00+ yr 

    00+ yr 

    00+ yr 

    62 yr

    spanh L/Deter.pipef the

    w beter, ituringould

    elinesSuchabedse of

    le to

    verytence

    andspan

    ution,) and

  • 8/17/2019 Piotr Krawczyk - Article

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    Drago et

    span evolprocess.lowering aThis washe evoluti

    actually pr 

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    processesmanagem

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    Fi

    pan celeri

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    (

    =

     

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    ty is calcul

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    odelledation wasct validati  to the a

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     [5] and [

    s an integenerallyn of the

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    esults of ae. This tolf-lowerin

    ealisticallyserved in

    an over   some pr  8.

    ture of th

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    n ongoingl is being  pipelineaccount

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    study to ddevelope  and is f for pipe

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    uary 28, 201

    se studie

    ne self-loof pipelinas carrieasureme reliable t

    evelop a t on the brther upgsoil inter L pipeline

    , the fiele overall

    odel

    ref. [8] an

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    , free

    eringself-d out.ts onool to

    ol forsis ofradedctionspan

    dataodel

    d [9]:

  • 8/17/2019 Piotr Krawczyk - Article

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     p

    q t  st 

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    =

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    sn = span

    st   = span

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  • 8/17/2019 Piotr Krawczyk - Article

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    6.

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    Conclus

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    7.

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    dynamic b

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    Referen

    [1] A Revi

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    [4] A StratFyrileivOffsho

     [5] Interac

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    [6] NumeriUnsteaProceeOffsho 

    [7] Drago,

    FatiguSixteeLisbon, 

    [8] HansedeveloMecha 

    [9] Klomp,(1995),1995

    Ma

     

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    uary 28, 201

    improvem

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    ipeline.suscepti

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    er 217

    ity of a T, H. Nes;

    s, K. Moth Intern

    Chen, R.gineering

    for Stead, G. Stce on O

    sis of Pi

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