De Vos, Leen

Frigaard, Peter

English

    Aalborg UniversitetWave Run-Up Offshore Windturbine FoundationsDe Vos, Leen; Frigaard, PeterPublication date:2005Document VersionEarly version, also known as pre-printLink to publication from Aalborg UniversityCitation for published version (APA):De Vos, L., & Frigaard, P. (2005). Wave Run-Up Offshore Windturbine Foundations.General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright ownersand it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.            ? Users may download and print one copy of any publication from the public portal for the purpose of private study or research.            ? You may not further distribute the material or use it for any profit-making activity or commercial gain            ? 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AALBORG UNIVERSITY Wave Forces on Offshore Windturbine Foundations on Borkum Riff Part C: Summary DEPARTMENT OF CIVIL ENGINEERING AALBORG UNIVERSITY SOHNGAARDSHOLMSVEJ 57 DK-9000 AALBORG DENMARK TELEPHONE +45 96 35 80 80 TELEFAX +45 98 14 25 SS Hydraul ics and Coastal Engineering No. 5 ISSN 1603-9874 December 2004 Wave Forces on Offshore Windturbine Foundations on Borku m Riff Part C: Summary By Brian Juul Larsen, Thomas Lykke Andersen & Peter Frigaard Aalborg University Wave Forces on Offshore Windturbine Foundations - Part C Contents Page Introduction 4 Tests 5 Results 6 References 9 Appendix 1 10 3 Wave Forces on Offshore Windturbine Foundations- Part C Introduction The present report is a summary of the reports by Juul Larsen and Frigaard (2004) and Lykke Andersen and Frigaard (November 2004). It also contains some additional force measurements on a cone shaped structure and some new force measurements on the concrete tripod. For further information on the conducted test programme contact Brian Juul Larsen (phone: +45 96 35 72 31, email: i5bjl@civil.aau.dk), Thomas Lykke Andesen (phone: +45 96 35 84 86, email: i5tla@civil.aau.dk) or Peter Frigaard (phone: 96 35 84 79, email: peter.frigaard@civil.aau.dk). All measures given in this report is in prototype values unless otherwise is stated. 4 Wave Forces on Offshore Windturbine Foundations - Part C Tests The overall test setup in the new tests are similar to the setup used in Juul Larsen and Frigaard (2004) and Lykke Andersen and Frigaard (November 2004). The water depth is 25 meters in all tests. At a water depth of 25 meters the models have the following eigenfrequencies: Cone 0.53 Hz Concrete tri 0. 3 9 Hz Table 1. Eigenfrequencies with a water depth of25 m. The JONSW AP wave spectrum has been used with a peak enhancement factor of 3.3. The concrete tripod is placed with two legs in the direction facing the waves and one directly backward. A description of the models can be found on page 47 and 48 in the report by Juul Larsen, De V os and Frigaard (November 2004). As in Lykke Andersen and Frigaard (November 2004) the data analysis has been performed by use of Wavelab using the same methods and techniques. 5 Wave Forces on Offshore Windturbine Foundations - Part C Results The largest positive and negative forces and moments measured during the tests are listed in table 2. Structure H!/3 Tp Fmax Fmin Mmax Mm in Test [m] [s] [kN] [kN] [kNm] [kNm] 1 Monopile 0.53 4.7 454 -393 9417 -6165 2 Monopile 1.65 6.6 1015 -871 25380 -11543 4 Monopile 3.70 8.0 2253 -2249 43860 -33447 5 Monopile 5.01 9.5 2432 -2451 46903 -29925 6 Monopile 5.74 10.3 2967 -2886 55926 -33607 7 Monopile 7.11 11.4 3056 -2914 69476 -31915 8 Monopile 7.84 12.9 3557 -3446 109122 -50266 9 Monopile 8.70 14.9 3843 -3760 96017 -48500 10 Monopile 1.51 5.7 1021 -893 17771 -11857 11 Monopile 3.73 8.2 2367 -1955 52246 -24892 12 Monopile 5.86 10.2 2782 -2636 58558 -32127 13 Monopile 7.84 11.8 3867 -3734 91038 -51478 14 Monopile 1.42 5.5 1155 -952 25882 -16324 15 Monopile 3.41 7.6 2131 -1932 50724 -27842 16 Monopile 5.63 9.8 2738 -2771 56548 -32524 17 Monopile 7.56 10.9 3359 -3277 90532 -41656 18 Monopile 1.79 6.4 1035 -980 20590 -20096 27 Monopile 2.99 9.8 1680 -1756 41196 -23324 28 Steel 1.62 6.6 1533 -1403 27149 -22197 29 Steel 3.70 9.5 2637 -2542 50299 -27717 30 Steel 5.69 12.1 3174 -3340 60807 -33837 31 Steel 7.62 13.5 3901 -4918 91466 -58595 32 Steel 1.49 6.1 1043 -1002 15922 -13016 33 Steel 3.51 8.5 2827 -2210 65896 -24248 34 Steel 5.71 10.3 3202 -3479 64040 -35499 35 Steel 7.84 12.1 3846 -4704 81824 -45403 TLA1 Monopile 7.93 12.9 3721 -2753 61960 -43720 TLA3 Concrete 7.80 12.5 6753 -5517 82780 -53060 TB01 Cone 3.56 9.5 4345 -4415 56810 -47610 TB02 Cone 4.23 9.5 5328 -4506 73090 -50610 TB03 Cone 6.86 12.1 8436 -6616 117000 -68820 TB04 Cone 7.51 13.9 8665 -6653 113100 -68280 TB05 Cone 8.71 13.9 8745 -6808 123400 -76210 TB06 Concrete 3.67 9.5 3413 -3241 47880 -37590 TB07 Concrete 4.06 9.3 3511 -3322 51090 -37050 TB08 Concrete 6.50 12.5 5044 -4901 67870 -48720 TB09 Concrete 7.27 12.9 6416 -4920 90370 -50120 TB10 Concrete 8.53 14.5 7196 -5084 90560 -52720 .. Table 2. Largest positive and negative forces and moments measured during the tests. 6 ti::~ ..,() /V ya >~t-'*' Wave Forces on Offshore Windturbine Foundations - Part C As a reasonable representative for the maximum and minimum forces of the tests the 1/250 values are compared in figure 1. 10000 0 Concrete tripod X 9000 X Steel tripod -1000 :}xx X Monopile X 8000 X Cone -2000 X~ X X X ll" X 7000 X -3000 X X )( ~ X 6000 -4000 X z X ~ ~ X X ~ ·~ X 5000 -5000 X X g X g X ~ <:! u.-4000 u.-~000 " X X X ' X X 3000 X 11 ~< X -7000 l6< X X~ X 2000 X~ -8000 X Concrete tripod X Steel tripod 1000 "f:x -9000 Monopile X X Cone 0 0 2 3 4 5 6 7 8 9 -10000 0 2 3 4 5 6 8 9 H,[m] H, (m] X 10' X 10' 15 0 X Concrete tripod X Steettripod ~ X X X Monopile X X Cone x x ~ X ~ X X X X X ~X X XX )( X X X 10 -5 X X X 'E X 'E X z X B. X ~ ! X X -~ 'x X g 1:; X X X ~ ~ X ;[ X 5 X )( X r(' -10 ~ X X Concrete tripod X Steel tripod ><.X i( X Monopile X Cone 0 -15 0 2 3 4 5 6 7 8 9 0 2 3 4 5 6 8 9 H5(m] H, [m] Figure 1. Comparison of measured 1/250 forces and moments. 7 (!{/::2 "o ~V v• -J•'t~ Wave Forces on Offshore Windturbine Foundations - Part C A summary of the works by Aalborg University on the Borkum Riffgrund project gives the following result plots: 10000 0 Concrete tripod X 9000 X Steel tripod -1000 )f'X X Monopile X X X X X 8000 X Cone -2000 ~,~ X xx X 7000 -3000 X X X X ~ X X 6000 -4000 " , ~ ~ X x X 5000 X -5000 X X X ~ ·~ u. X u. X 4000 *'~< -6000 X X X X X 3000 X -7000 X X X X xX X ~ X 2000 -8000 X Concrete tripod " Steel tripod 1000 'S.scx -9000 X Monopile X X Cone 0 -10000 0 2 3 4 5 6 7 8 9 0 2 3 4 5 6 7 8 9 H5[m] H5[m] X 104 X 104 15 0 X Concrete tripod X Steel tripod !'x X Monopile X X xx X Cone X ' X X X X ~ X X X X X x X' x X 10 -5 X ' X ' "' X X X 'E 'I< 'E X X z a ~ X ~ X 0 X X E ::;: '( ::;: X )< 5 X ~ X -10 X X x~x X Concrete tripod X Steel tripod "'< X Mono pile X Cone 0 -15 0 2 3 4 5 6 7 8 9 0 2 3 4 5 6 7 8 9 H5[m] H5[m] Figure 2. Comparison of largest measured forces and moments. 8 Wave Forces on Offshore Windturbine Foundations - Part C 25 X X X -20 §. X "E ·o !l. ""' 0 .. 15 X ~ 10 5 l I " Mono pile X Monopile Boussinesq calcultaions 0 0 2 4 6 8 10 12 H,[m] Figure 3. Comparison of measured attack point of largest forces with some Boussinesq calculations. References Juul Larsen, B. and Frigaard, P. (2004): Wave Forces on Offshore Windturbine Foundations on Borkurn Riff. Department of Civil Engineering, Aalborg University, Hydraulic and Coastal Engineering No. 5, ISSN 1603-9874 Lykke Andersen, T. and Frigaard, P. (November 2004): Wave Forces on Offshore Windturbine Foundations on Borkum Riff- Part B: Verification Tests. Department of Civil Engineering, Aalborg University, Hydraulic and Coastal Engineering No. 5, ISSN 1603-9874 Juul Larsen, B., De V os, L. and Frigaard, P. (November 2004): Scour around Offshore Windturbine Foundations on Borkum Riffgrund. Department of Civil Engineering, Aalborg University, Hydraulic and Coastal Engineering No. 9, ISSN 1603-9874 9 Wave Forces on Offshore Windturbine Foundations- Part C Appendix 1 - Result Plots Test TBOl • With a cone structure • H 1,3 = 3.56 m, Tp = 9.5 s • Maximum force: 4345 kN • Minimum force : -4415 kN • Maximum moment: 56810 kNm • Minimum moment: -47610 kNm ~ ~ "-.... NE X 107 6.--------~-----~--· X X xX -4 X X X xx )(X X X X X .· ~5~-------~--------~5 F"'ce(NJ x 108 X 108 5,-----~---~----~----, 1 0 -1 -2 -3 -4 · 5 10.2 10° 10' 102 Ex. Prob. (%] Incident wave spectrum at structure 25 20 ;: 15 ] ~ 10 u ~ <J) 0 0 0.05 0.25 0.3 0 .35 0 .4 Frequency (Hz] 10 X 107 6~--~----~----~====c===~ --~ e1-.·1o7 (m] --~ F·10(N] --- M (Nm] -2 -4 ~L---~--~---~--~--~ 1000 1020 1040 1060 1080 1100 Time (s] 50,-----------40 30 I 20 ~ "" 10 ~ ;! ~ 0.. .:i 0 -10 ·20 Force (N] X 101 X 107 s.-----c~ -, -----~----~----. -2 -4 ~OL~------~10-.,-------1~ ~-----1~0,------~102 Ex. Prob. (%] Incident wave height distribution at structure 102---~---.....::--~---~---, 10' 10° 10"' L---~---~--~--''--'-'<---" 0 4 Wave Forces on Offshore Windturbine Foundations - Part C Test TB02 • With a cone structure • H 113 = 4.23 m, Tp = 9.5 s • Maximum force: 5328 kN • Minimum force: -4506 kN • Maximum moment: 73090 kNm • Minimum moment: -50610 kNm X 107 8~--~----~----~----~--~----. ~ 4 8 & 2 -4 • " X .eL---~--._--~--~--~--~ ~ -4 -2 0 6 Force (N] x to• X • ·2 -4 X X ~~------~------~------~------~ 1~ 1~1 1~ 1~ 1~ Ex. Prob. [%] Incident wave spectrum at structure 40.--.----r--,---.--~--~-----, 35 tO j ~ 0.05 O.t O.t5 0.2 0.25 0.3 0.35 0.4 Frequency [Hz] 11 --Eta1•10' [m] --PtO[N] --M(Nm] ~ ~ tOOO t 020 t040 t060 t080 ttOO Time(s] 50 40 30 I 20 c 0 Q. tO i! .. ~ 0 -tO -20 ~ -4 ·2 0 Force [N] x 108 8 X 107 -2 -4 ~L_ ___ _. ____ ~----~-------~ 10"2 10"1 10° 101 102 Ex. Prob. [%] tO'~-~-'"-~~e-nt_w_a_verh_e~_h_l~di_str_ib_u_lio~n-at_s_tr~u~_u_r• ______ , to' to·' "--~-~--~----._--"0':-__ _. _ _,..,_.____. 0 0.5 t .5 2 2.5 3.5 (HIH/ Wave Forces on Offshore Windturbine Foundations - Part C Test TB03 • With a cone structure 1.5 X 10_, --Eta;107 (m) - -P10(NJ • H113 = 6.86 m, Tp = 12.1 s --M(NmJ 0.5 • Maximum force: 8436 kN 1\~Nfft 0 • Minimum force: -6616 kN ,jJ .0.5 • Maximum moment: 117000 kNm -1 1000 1020 1040 1060 1060 1100 • Minimum moment: -68820 kNm Tome(s) X 107 12 X 50 X 10 40 'E 30 ~ 6 j 4 I 20 :g X ~ 2 0. 51 ~ X .. 0 "' I <-2 ::; -4 -6 -8 -6 10 Force (NJ X 106 x107 10 X 106 12 X 107 10 X x .... 6 ~ 2 'E 4 ~ ~ "-;: " E0 2 ::; -2 -2 -4 -4 -6 xn -6 -6 10"2 10"1 100 10' 10' -6 10.2 10.1 10° 101 101 Ex. Prob. (%) Ex. Prob. (%1 InCident wave spectrum at structure 150 10' Incident wave height distribution at structure N~ 1()0 101 -~ l: .0 " e '0 Q_ ~ i 50 "' J 0 ~--- 10'1 0 0.05 01 0 .15 0.2 0.25 0 .3 0.35 0.4 0 0.5 1.5 2.5 3.5 4 Frequency (Hz} (HIH/ 12 Wave Forces on Offshore Windturbine Foundations - Part C Test TB04 • With a cone structure • H L'3 = 7.51 m, Tp = 13.9 s • Maximum force: 8665 kN • Minimum force: -6653 kN • Maximum moment: 113100 kNm • Minimum moment: -68280 kNm 10 'E ~ 6 E ~ 4 * 2 .. 0 1 -2 -4 -~L---~--~--~--~--~--~--~--~~10 6 ;[ 2 8 ~ 0 -2 -4 Force (N) x 10e -8~------~--------~------~--------~ 10"2 10.1 10° 101 102 Ex. Prob. (%] Incident wave spectrum at structure 150 r-------~--~--~--~----~------. 160 40 ) ~ 20 0 0 0.05 0.1 0 .15 0.2 0 .25 0.3 0 .35 0.4 Frequency (Hz) 13 X 108 1 .5~--~--~----.-;=====,-, ---- Eta;1o7 (m( ---- F"10 (N) - - M(Nm] .0.5 -1 1000 1020 1040 1060 1080 1100 Time(s) 50 40 I ~ xx' a. j -10 -20 -1 Fa<ce (N) X 107 12 )( 107 10 8 . .,._. 'E 4 ~ ~ 2 ::t 0 -2 -4 ~ -8 10"2 10·' 10° 101 102 Ex. Prob. (%] 102 Incident wave height distribution at structure 101 ~ D e a. .li 10° X 10.1 0 0.5 1.5 2.5 3.5 (HIH/ Wave Forces on Offshore Windturbine Foundations - Part C Test TBOS • With a cone structure • H113 = 8.71 m, Tp = 13.9 s • Maximum force: 8745 kN • Minimum force: -6808 kN • Maximum moment: 123400 kNm • Minimum moment: -76210 kNm x 108 1 .5,--~-~-~-~--r---r---r--~-., ·2 X 106 0 2 Force (N) 10 r----~-------~----------., !: 2 8 ~ 0 ·2 ' X X X X X ~~---~----~---~----~ 1~ 1~1 1~ 101 1~ Ex. Prob. (%] Incident wave spectfum at structure 250 200 ;;; NE ;: 150 ·~ .., ~ 100 ) !l. ~ "' 50 0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 Frequency (Hz) 14 X 10e: 1 .5,--~-----~r=====:::;l -- Eta1*107 [m) --F"10(NJ --M(Nm] ·11o'="oo=---...,.1 0::':2 -::o---:1":'04-:o-...,.--1:-::06'::-o::---...,.1080~---:1.J100 ~ 20 ·~ c. 10 g ~ 0 ·10 ·20 ·1 T1me (s] Force (N) X 108 1 .5r-:c._.--~---~----~-~-.., e ~ 0.5 ! ~ ~.5 -1 10-2 10° 10' 102 Ex. Prob. (%] 10' Incident wave height distribution at structure 10' ·x y 10.1 0 0.5 1.5 2.5 3.5 4 (HIH,)' Wave Forces on Offshore Windturbine Foundations - Part C Test TB06 5 x to' • With a concrete tripod structure --Eta;"107 (m) - -F"10 (N) • H113 = 3.67 m, Tp = 9.5 s --M(Nm) • Maximum force: 3413 kN • Minimum force: -3241 kN ·2 • Maximum moment: 47880 kNm · 3 -4 1000 1020 1040 1060 1080 1100 • Minimum moment: -37590 kNm Tlme(s) 5 X 101 50 4 '!< X 40 'E 3 XX z 30 'E 2 I ~ 20 ~ .. 0.. :ll 0 ~ 10 "iii c = ~ -1 < 0 ::; ·2 ·10 .J · 20 ·4 -4 -4 Force (NJ X 106 Force [N) X 101 X 105 X 107 4 5 • x x ~ 'E ~1 8 0 c 0 ~ 0 "-·1 ::; ·1 ·2 ·2 ·3 .J X X XX < -4 10 ... 10"' 10° 10' 102 -4 10·2 10.1 10° 10' 102 Ex. Prob. [%) Ex. Prob. [%) Incident wave spectrum at structure 102 InCident wave height distribution at structure 35 30 ';j' 25 101 N.s f 20 ~ , , "' " £ 70 15 ,:j ~ 10° br 10 ~ J 0 10"1 0 0.05 0.1 0.15 0.2 0.25 0.3 0 .35 0.4 0 0.5 1.5 2.5 3.5 Frequency [Hz) IHIH/ 15 Wave Forces on Offshore Windturbine Foundations - Part C Test TB07 • With a concrete tripod structure • H 1,3 = 4.06 m, Tp = 9.3 s • Maximum force: 3511 kN • Minimum force: -3322 kN • Maximum moment: 51090 kNm • Minimum moment: -37050 kNm E ;;. 3 E i 2 ~ 1 1i 0 i ·1 ::; -2 -3 -1 -2 Force [NJ X X X ,, XX -4L- -_ _. _ _ __ ~---~----~ 10"2 10'1 10° 101 102 Ex. Prob. (%] Incident wave spectrum at structure 35 30 ';j' 25 N.§. ~ 20 " , ~ 15 j 10 0 / ~ 0 0.05 0.1 0.15 0 .2 0.25 0.3 0.35 0.4 Frequency [Hz) I ;: '15 "-i! .!! < ~ D e "-16 X 101 sr---~----~----~====c===~ --Eta1"107 [m[ --P10[N) --M(Nm) :~ 0 ' -1 -2 -3 -4 1000 1020 1040 1060 1080 1100 Time [s) 50 40 30 20 10 Force [NJ X 105 X X liC )( '">< -1 -2 -J -4L-----~-----~----~----~ 10-2 10"1 10° 101 101 Ex. Prob. {%) Incident wave height distribution at structure 10' ~ "'-~<  ~ 10·1 0 0.5 1.5 2.5 3.5 4 (HIH/ Wave Forces on Offshore Windturbine Foundations - Part C Test TB08 • With a concrete tripod structure • H1,3 = 6.50 m, Tp = 12.5 s • Maximum force: 5044 kN • Minimum force: -4901 kN • Maximum moment: 67870 kNm • Minimum moment: -48720 kNm X )()( -~~--~~----~-2-----70-----7-----4~--~ Force(NJ ~~------~------~------~------~ 10-2 10"' 10° 101 102 Ex. Prob. (%] InCident wave spectrum at structure 120 r-------~--~--~----~--~-------, 100 20 } 0~~·~~~--<--------..J 0 0.05 0.1 0 .15 0.2 0.25 0.3 0.35 0.4 Frequency (Hz) 17 .eL----~----~---~~--~---' 1000 1020 1040 1060 1080 1100 ·20 ~ Time (s] Force (N) Incident wave height distribution at structure 102~------~---r--~----~--~------. 10' 10'' '----~--~--~--~--~---~--"-------' 0 0.5 1.5 2 2.5 3.5 (HIH/ Wave Forces on Offshore Windturbine Foundations - Part C TestTB09 • With a concrete tripod structure X 101 tO~----~----~----~r===~====~ -- Eta1•to7 {m] --F'tO{N] • H 113 = 7.27 m, TP = 12.9 s 6 -- M (Nm] • Maximum force: 6416 kN • Minimum force: -4920 kN • Maximum moment: 90370 kNm -4 -6 tOOO t020 t040 t060 t060 ttOO • Minimum moment: -50120 kNm Time (s] 50 40 30 I 20 "E ·c; "- tO j ·20 -6 -4 Force (N] X 10° X 10' 6r---------------~----------------~ tO X 107 6 .< y ~ 2 ~ 0 u. 0 ·2 ·2 -4 -4 X X -6 to·' 100 -eL-------~------~--------~------~ 1~ ,~, 1~ 101 1~ Ex. Prob. {%] Ex. Prob. {%] t20 Incident wave spectrum at structure lncJdent wave height distribution at structure tOO ... N.E. 60 f 60 to ' ~ D e "-~ tl ~ c. "' 40 \!le 20 X 0 0 10"1 0 0.5 t .5 2.5 3.5 0.2 0.25 0.3 0.35 0 .4 Frequency {Hz] (HIH/ 18 Wave Forces on Offshore Windturbine Foundations- Part C Test TBlO • With a concrete tripod structure • R t.·3 = 8.53 m, TP = 14.5 s • Maximum force: 7196 kN • Minimum force: -5084 kN • Maximum moment: 90560 kNm • Minimum moment: -52720 kNm Force (N) X 101 6 X X X.JI. -2 -4 -6~------~--------~------~--------~ 10-2 10., 10° 101 10:f Ex. Prob. j%) Incident wave spectrum at structure 180 r---,---r-------~--~--~-------, 160 140 N~ 120 f 100 80 ! 60 40 20 0 J 0 0.05 0.1 '""'---0 .15 0.2 0.25 0.3 0 .35 0 .4 Frequency (Hz) 19 X 107 10r-----~----~----~r===~==~~ -- Eta,"107 (m] --F"10 (N] - - M(Nm) -6 1000 1020 1040 100) 1080 1100 Time(s] 50 40 30 I "E "i5 20 0.. tO tl ~ 0 -10 -20 Forte (N] 10 X 107 6 E 4 ~ "E 2 ~ -2 .l)L-------~--------~------~--------~ 1~2 1~1 1~ 101 1~ Ex. Prob. (%) 10'' ~--:"::---~--~-::---~--:'":--~----:":- ~ 0 0.5 1.5 2 2.5 3.5 (H/H/ 

Wave Run-Up Offshore Windturbine Foundations

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Wave Run-Up Offshore Windturbine Foundations

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