The Future For Monopile & Jacket Pile Connections – Developer &I nvestor Perspectives 27 th October 2014 , PES/ Pagel I TW, Amsterdam Dr. Chris Golightly GO-ELS Ltd. Geotechnical & Engineering Geology Consultant Summary Contents • History of Monopile [ MP] Connections • DNV J101 Code and Shear Keys • Adoption of High Strength Grouts • Monopile Vs Tripod/ Jacket Loading • Billington I CE 2014 ( Refs 1 & 2) • RWE GYM Study 2011 • Conical Connections • Trelleborg Spring Bearings ( Ref. 11) • Sw aging & Slip Joints • I ntegral and External Mating • Quick Coupling; I ntegral MP & TP • Fatigue Life; OWI - LAB BELWI ND ( Refs. 3 & 4) • Conclusions, References, Contact Details Dr. C. R. Golightly GO-ELS Ltd. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 History of Monopile Connections The 1st UK Round 1 Blyth and Scroby Sands MP projects used bolted pre-fitted welded flange connections, a technique subsequently rejected in favour of the perceived cheaper and quicker more efficient grouting technique. Towards the end of 2009 many grouted connection joints, between large diameter monopiles [ MP] and connecting tubular steel transition pieces [ TP] at the base of overlying support towers, were found to be failing. For the majority of the 70% of UK offshore MPs which experienced grout cracking, settlements and failures. This was primarily due to the widespread absence of shear keys (or weld beads) on straight MP and transition piece [ TP] surfaces. Bending moments as a result of complex wind and wave loading is an important design consideration. Axial connection capacity was found to be very significantly lower than previously assumed due to MP scale effect, a lack of manufacturing and installation tolerances and abrasive wear due to the sliding of contact surfaces when subjected to large moments. Typical failure modes include disbonding, cracking, wear and compressive grout crushing failure. These failures have necessitated assessment and repairs which have not all been fully reported publically. There have been a number of claims and arbitration cases. Dr. C. R. Golightly GO-ELS Ltd. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 R. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 .History of Monopile Connections Dr. Golightly GO-ELS Ltd. C. Research is ongoing on scale & fatigue effects but the situation is becoming clearer. The use of “Plain Pipe” non shear keyed connections is now discontinued. The DNV J101 (2007) offshore wind turbine design code left it open to designers whether to use shear keys/ weld beads or not. Refs 5. I ndustry best practice and code guidelines are under review & DNV guidelines were revised in 2011 (new Code to be issued in 2014. This might be regarded by some as “engineering for failure”. quicker option. The use of annulus grouting allowed easier adjustment of the pile out-of-verticality using jacking to level the turbine tower prior to grouting. not recommended and was essentially a systemic design error as a result of code phrasing omissions. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . There are still some anomalies in behaviour. 6 & 7). R. Dr. allowing radial stresses to be regained. Golightly GO-ELS Ltd.DNV J101 Code and Shear Keys The two projects where grouted connections have not (yet?) failed included shear keys. C. which is common practice for oil and gas platforms for pile to sleeve connections using the API RP2A Code. This is due to the designers having Oil & Gas industry experience and staff I t appears that many designers did not include shear keys because it was perceived as a cheaper. Some MP projects still adopt designs without shear keys. including a 1 to 3 degree conical section which is presumed to be able to “catch” the TP as the grouted connection ultimately settles and drops. The MP grout failures may have been related to manufacturing. R. as a more efficient alternative to bolted flanges.Adoption of High Strength Grouts Tried and tested appropriate underwater grouts were originally used to cement piles into bedrock. following work by Anders & Lohaus (2007) and Soerensen et al (2011). There have been question marks over the long term fatigue strength of HPC grouts. I n a geological context. Typically. C. according to standard rock engineering strength descriptions. This technique was then adopted over 12 years ago for offshore wind turbines. with the grouted annulus thicknesses therefore varying vertically. There are suggestions in the work done now that a lower strength less brittle grout may be more appropriate for use in some designs. which assisted in levelling towers to vertical. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . I t is not difficult to envisage twin large diameter steel tubes sandwiching an annulus of such “rock” cracking & crushing. brittle high and ultra high strength grouts used have UC strengths > 100 MPa up to 200 MPa. Little to nothing is published on this. There is a need to "bottom-out" the potential water ingress and cyclic fatigue problems. amongst other applications. They exhibit high ratios of compressive to tensile strength. Golightly GO-ELS Ltd. this is a “Very Strong” rock which could “only be chipped by heavy hammer blows”. installation and positioning tolerance uncertainties and out-of-roundness which in some cases have led to MPs and TPs both being slightly out of shape. leading to progressive failure at the top and base as piles are cyclically loaded by wind and waves over long periods. should grout be adopted. Dr. Patterns of cracking measured are reputedly linked to predominant environmental load directions. R. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . 10. High dead weight oil & gas platforms have used API RP2A designed grouted leg-pile connections for decades. C. However OWTs are low deadweight loaded.g. MP ability to transfer large moments is complex. Borkum West 2) These “belt-and-braces” designs suggest a lack of confidence in the robustness under long term cyclic fatigue conditions over a 20+ year design life. but has become better understood. Design theories still have limitations & shortfalls. Golightly GO-ELS Ltd. 16. The use of conical TP sections [ “controlled engineering for failure”] is uncertain in the long term. Dr.Monopile Vs Tripod/ Jacket Loading “Monopiles” with D/ t ratios often in excess of 100 are in reality “thin-walled steel caissons” rather than piles. highly cyclic. Dynamic load regimes experienced by the legs of tripods (Germany) and 4-leg jackets (mostly UK) are different to the predominant bending mode experienced by MPs. 17 & 18). but stresses are usually predominantly compressive. with tensile stress zones in the grout. I t is uncertain whether or not tripods/ jacket grouted connections will experience fatigue degradation in time. There has been extensive research especially at Leibnitz University Hannover (Refs. even with the provision of shear keys. with complex vertical & bending force coupling. (e. Some tripod and jacket designs include “stopper plates”. Option (2) is preferable. Tripods lowered onto template pre-driven pile groups [ Borkum West 2] or: 2. with a large annulus of lower strength grout used to allow for installation tolerances. Golightly GO-ELS Ltd. which requires more complicated sealing and a different grout stress pattern. as opposed to outside.5 m. Dr. work mostly in Germany under the auspices of the German BSH committee has shown that with a different "push-pull" loading regime to monopiles. since the tripod or jacket leg sits inside the pile. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . R. C.Monopile Vs Tripod/ Jacket Loading For tripod/ jacket piles of smaller diameter up to ~ 2. Two methods were used for German AV tripods: 1. correctly designed and installed/ constructed. where the jacket legs were stabbed inside a pre-installed seabed pile template. there is no theoretical reason why grout should not be used for those connections. This is similar to that used for the Ormonde I rish Sea project appears preferable. Piles vibrated then conventionally driven through the sleeves of pre-placed tripods [ Global Tech 1] ] . with shear keys. which would lead to a simplified seal specification. Dr. Five concept variants emerged from this process as potential solutions.Mor Study 2011 Julian Garnsey of RWE led a study published in 2011 assessing grouted connections for the GYM monopiles (Ref. Golightly GO-ELS Ltd. The project assessed eight generic concepts: 1) Grouted conical without shear keys.Y. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . but was not selected because the change would have impacted on the project schedule. 3) Bolted flange. 2) Grouted cylinder with shear keys. 7) Pinned Connection. 8). Concluded best solution is shear keys in the middle third and a longer connection plus necessary “back-up” elastomeric bearing support. C. 1) Grouted conical without shear keys and an axial bearing system 2) Grouted cylinder with shear keys and an axial bearing system 3) Bolted flange internal to the transition piece above high tide level 4) Conical grouted connection without shear keys and an axial bearing system 5) Conical grouted connection without shear keys. 5) Swaged Connection. R. 8) Clamped Connection The bolted flange proved the most promising for further detailed investigation. 6) I ntegrated MP and TP. 4) Bracket support. allowing lower strength grout. Necessary to confirm zero water ingress does not adversely affecting the grout matrix.RWE Gw ent. This more robust connection with reduced contact pressures at the ends and a less brittle grout would reduce cracking around the shear keys and connection ends. C.RWE Gw ent.Y. Golightly GO-ELS Ltd. R.Mor Study 2011 The methodology developed resulted in a numerical weighting for EI GHT criteria as follows. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . with the subsequent ranking shown: Dr. Dr. so a design procedure with conical shaped connections was developed. C. R. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . Golightly GO-ELS Ltd. Axial capacity was found to be more sensitive to diameter and surface/ positioning tolerances than allowed for in existing design standards. I n January 2011 a further JI P on the capacity of cylindrical shaped grouted connections with shear keys was initiated. 6 & 7). Analytical design equations were developed for the Ultimate and Fatigue Limit States. The recommended design methodology was supported by laboratory tests.Conical Connections A Joint I ndustry Project [ JI P] was carried out by DNV to investigate the structural capacity of these connections from autumn 2009 to January 2011 (Refs 5. The solution is used on installed wind farms where grout problems occur but also as a precaution. C. Robin Rigg [ 360] . the bearings are gradually loaded to assist the grout in supporting the weight of the TP and tower assembly.Trelleborg Spring Bearings Several projects adopted or are adopting retro-fitted/ new Trelleborg spring bearings (BELWI ND [ 330] . Long Term Measurement & Condition Monitoring is Essential Dr. At the start of construction. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . Greater Gabbard 120] . A further function of the bearing is preloading to carry the static vertical load from the start with the aim of preserving the strength of the grout. I f elastomeric bearings were not fitted during construction and slippage occurred later. the bearings can be fitted so that they are unloaded and just resting at the top of the MP. Rhyl Flats [ 158] and Gwent Y Mor [ 960] ). 11). R. they may be retrofitted by welding new brackets to the inside of the TP. I f slippage occurs at a later stage. For a normal monopile foundation six bearings are required (see Ref. Golightly GO-ELS Ltd. Sheringham Shoal [ 540] . Golightly GO-ELS Ltd. which secures structures by expanding piles radially into surrounding sleeve in substructure.g. R. Dr. Costly. pile swaging. with some considering integral MP & TP. C. Easily monitored and quicker. or slip joints as reliable long term solutions. All require control on verticality. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . careful driving. internal/ external mating. but more expensive. Beatrice project (DownVI nD) pile swaging (Hydra-Lok® system) for jackets.On for Amrumbank and Humber Gateway have reverted to bolted flanges.Sw aging and Slip Joints Many developers such as E. e. quick coupling lock rings. Golightly GO-ELS Ltd.I ntegral and External Mating Dr. R. C. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . I ntegral MP & TP http:/ / w w w .com/ assets/ misc_d ec/ vanoordpdf. Dr.pdf Van Oord @ Luchterduinen and Gemini: “Next year in July we will start with piling the first foundations. C. By doing this we prevent a grouted connection between the mono pile and transition piece. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . R. After piling the secondary steel will be attached to pre-mounted brackets. Golightly GO-ELS Ltd. Those are quite innovative as it is a combined monopile and transition piece.eu.Quick Coupling. We are piling on the flange on which the wind turbine tower will be mounted.384857351196. At the same time this concept is cheaper than a foundation in two parts”.pes. 5 Hz. Strength after 28 days curing in water at 20 o C.35 Hz.35 Hz than at either 5 Hz or 10 Hz. which represent two different load-bearing mechanisms and a very ductile failure” Soerensen et al ( Ref 19) • BASF 140 MPa high performance grout. Soerensen et al. and 10 Hz) had no influence on the fatigue strength. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . • Fatigue life reduction in water was not observed at the lowest stress level investigated (45% of the static compressive strength). cementitious binder material containing microsilica and other added minerals. C. Golightly GO-ELS Ltd. • Reduced fatigue capacity postulated due to water trapped during cyclic loading. Reduction in fatigue life in water was particularly severe at the lowest frequency 0. Dr. 13) “The fatigue strength of UHPC in high-cycle fatigue seems to be lower compared to normal strength concrete. • I n air.Fatigue Life ( Lohaus & Anders 2007. Effect more pronounced at low loading frequencies. but in water the grout exhibited drastically shorter fatigue life at stress levels in excess of 60% of the static compressive strength.35 Hz. • I n air grout fatigue life was comparable to that of ordinary concrete. R. Prepared at ultra-low water/ cement ratio using superplasticizing admixture. the frequency of the loading (0. Aggregate natural sand (0-4 mm). but in water the fatigue capacity was much lower at 0. exerting internal pore pressures high enough to cause progressive crack formation (“micro-wedging”?). Regarding UHPC in grouted Joints nearly bilinear load-deflection curves for specimens with shear keys in uniaxial compression are shown. with time available for water ingress and subsequent pressure build-up during each load cycle. 2011) Lohaus & Anders ( Ref. R. 19) Dr. Soerensen et al. C.Fatigue Life ( Lohaus & Anders. 13. Golightly GO-ELS Ltd. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . Ref. Ref. CAPEX and investment is still limited compared to other energy industries. I nitially the relatively new offshore industry has understandably used conservative monopile. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . scour protection and J-tubes. I ndustry needs to be more realistic about offshore turbine tilt criteria. C. Conservative risk averse attitudes in a relatively new industry should change as experience is gained. 3. For foundation costs to reduce [ halved acc. triple & 4-leg jackets. monopod suction caisson. European Offshore Wind I ndustry has developed several alternative foundation solutions. tilt and settlement. selected/ tailored to specific site conditions. pile tip buckling. stiff. 2. Golightly GO-ELS Ltd. innovative solutions needed. unplanned drilling/ re-driving. triple/ quad suction caissons. Main Foundation Risks: Grouted connections. piling noise mitigation. twisted jacket. internal & external corrosion. 1200 Tonne. concrete GBS. influencing business cases. US DoE] . over-conservative long. Big impact on structure costs. Development of tilt-tolerant DD turbines can reduce costs. Dr. piled tripod (Germany) & 4-leg jacket (UK) solutions. “Alpha Ventus” piled tripods.Main Conclusions: Foundations 1. guyed & A-frame monopiles. 60 m + length monopiles in ~ 40 m WD may be questionable & should be challenged. based upon sound engineering analysis. steel / concrete. 6. R. BARD tripiles. monopiles. 5. 4. truss towers.. The industry current push [ Project PI SA] to move to ~ 10 m dia. heavy pile design. Bolted flanges or other direct connections are possible. M easurement. London Array] . bolted flanges [ Amrumbank. 3.25 * D [ Schaumann] . New single piece MP-TP [ Achterduinen] 4. retro-fitted bearings [ Robin Rigg. R. I ndications from 2 major studies by Centrica/ RES [ Race Bank] and RWE [ Gwent-Y-Mor] indicate that cost differential between bolted flanges and grout is minimal. Sheringham Shoal] shear keyed with new elastomeric bearings [ BELWI ND] . Questionable whether or not non shear keyed conical [ 1 o-3o] sections and/ or will remain “fully robust” for fatigue design lifetimes of 20+ years? 6. Humber Gateway] . 3 & 4) Dr. Questions regarding long term fatigue behaviour under high loading with water ingress? 7. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 .Main Conclusions: Grouted Connections 1. This was a systemic design error over a long period. Discovery from late 2009 that > 70% of UK MPs failed. I f MP grouting is adopted use of shear keys & robust grout seals is essential plus overlap length of at least 1. M onitoring and M itigation for offshore structures is essential for long term design life O&M cost minimisation. 5. Full review of retro-fitted elastomeric bearings projects shows these should be robust and acceptable with condition monitoring and displacement measurement required for full design life. 2. Golightly GO-ELS Ltd. The BELWI ND project is state-of-the-art (Refs. settled and cracked. Developers are now (mid 2014) adopting: none shear keyed conical [ Anholt. C. 04/ 12/ 2013. K. Certification of Grouted Connections for Offshore Wind Turbines. Billington.pdf Dr. Pushed Beyond Their Limits”. DNVOS-J101.. Billington.org/ annual2014/ conference/ posters/ PO_266_EWEApresentation2014. “Failures of Large Diameter Grouted Connections in Monopile Supported Offshore Wind Farms and implications for I SO 19902”.uk/ topics/ energy/ Recorded-lectures 3..R. • OGP-BP Structural Reliability Conference 4 December 2012. “The Future of Monopile Grouted Connections in Offshore Wind Farms – A Client’ s Perspective”... C. (2011). “Foundation Monitoring Systems: Analysis of 2 Years of Monitoring at the North Sea”.ogp.asp www. EWEA 2014. “Foundation Monitoring Systems for Optimized O&M and Lifetime Assessment”.uk/ recentmeetings.org. Golightly. Van I ngelgem. “Grouted Connections – What Can Be Learned From Previous R&D and the Monopile Failures to Help the Offshore I ndustry Design Reliable Connections?”. Summary Report from the JI P on the Capacity of Grouted Connections in Offshore Wind Turbine Structures.. Verlinden. R. Jan Jordaens. C. http: / / wiki-cleantech. G. PO 0266.eu/ sites/ default/ files/ EWEAOffshore_2013_Poster_Christof_Devriendt. 7. Amsterdam November 2011. www. 8. Design of Offshore Wind Turbine Structures. De Wilde. C. Weijtjens.References ( 1) 1. 14. Civil Engineers. De Wilde.pdf 4.pdf 2. http: / / info. (2013). C. Proc. C.pdf 5.uk/ Journals/ 2014/ 06/ 03/ z/ h/ d/ GE-January-2014-Tilting-of-monopiles-Golightly. Norway: Det Norske Veritas. and Devriendt. Ref. (2014). De Sitter. I nst..ewea. Devriendt.nce. P. Proc. C. (2010). DNV. http: / / bruwind. Garnsey (2011). (2012). Ref. Verlinden. PO 0201. Y.ice.. (2013). C.org. Vanden Haute. Golightly GO-ELS Ltd.. Heavy and Stiff. S. D. De Sitter. pp. http: / / proceedings. DNV. (2014). – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . W. Ground Engineering. 20 – 23. EWEA 2013. London March 3 rd 2014.uk/ standards/ 1212London/ Presentations/ 02-5bBillington.com/ wind-energy/ the-future-of-monopile-grouted-connections-a-clients-perspective 9. EWEA 2011. DNV. November 2013.. Norway: Det Norske Veritas. D. S. K. Norway: DET NORSKE VERI TAS AS. G. Offshore Engineering Society Presentation.oes. and Millis... Proc. Long. Van I ngelgem. Y.co. www. January 2014.org. p. (2014). March 2014. “Tilting of Monopiles. 6. Millis. (2013). 10th German Wind Energy Conference DEWEK. (2014). Proc. I nstitut für Stahlbau. (2007). pp.1002/ stab.org/ journal/ volumes/ volume-91/ issues/ issue-1/ articles/ research-capacity-of-cylindrical-shaped-grouted-co 13. “ High-cycle Fatigue of “Ultra-High Performance Concrete” and “Grouted Joints” for Offshore Wind Energy Turbines”. Oerlemans. www. and Lervik. P.. A. Golightly GO-ELS Ltd. Vol.Analyses and Discussion of Earlier Design Approaches for Connections without Shear Keys: . 91(I ssue 1). Proc. S. (2012). I . Schaumann. Springer-Verlag. A. 17 th – 18th November 2010. (I SOPE). Lohaus. Twenty-fourth (2014) I nternational Ocean and Polar Engineering Conference. www. I ..pdf 17.org/ docs/ 2014papers. January 2013. and Lervik.baufachinformation. Lochte-Holtgreven. Dr. 15.. Lotsberg. 309 – 312. pp. 2007. General & I ntroductory Civil Engineering & Construction..isope2014. Busan. R.. S. Wilke.247 S.References ( 2) 10. 31 st October 2012. VI I I .201201598. R.. John Wiley & Sons. www. “Design of Grouted Connections for Monopile Offshore Structures. Bertnes. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . Bertnes. Band 29. Results from Two Joint I ndustry Projects”. 2014. A. Hannover.biz/ 2014/ 07/ 18/ monopile-gripper-frame-fitted-on-van-oords-jack-up/ 16. 2013.. Lochte-Holtgreven. 42 – 48. Schaumann. www. P. A.de/ buch/ Zum-Trag-und-Ermüdungsverhalten-biegebeanspruchter-Grouted-Joints-in-OffshoreWindenergieanlagen/ 241371 11. Serednicki. H. Lotsberg. A.lorc. Serednicki. June 15-20.. “Overcoming Problems With Crumbling Grout”. 47-54. Euromech Colloquium on Wind Energy. Lochte-Holtgreven. “Bending Tests on Grouted Joints for Monopile Support Structures”. “Capacity of Cylindrical Shaped Grouted Connections with Shear Keys in Offshore Structures”. Schriftenreihe des I nstituts für Stahlbau der Universität Hannover.. Univ. (2010). LORC (2012). 14. A. S. Proc. Korea. “Monopile Gripper Frame Fitted on Van Oord’ s Jack-Up”. Offshore WindBiz (2014). pp.dk/ oceanwise-magazine/ archive/ 2012-2/ overcoming-problems-with-crumbling-grout 12. “Zum Trag. H. “Grouted Joints in Monopiles . www. The Structural Engineer. (2013). R. C. DOI : 10. F. Bechtel..und Ermüdungsverhalten Biegebeanspruchter Grouted Joints in OffshoreWindenergieanlagen”.istructe. and Anders. Oerlemans.offshorewind. 18th July 2014. S. Amsterdam November 2011. PO 178. “ Nonlinear Structural Dynamics of Offshore Wind Energy Converters with Grouted Transition Piece”.windenergyupdate. http: / / social. C. www.windpowermonthly. London High Court of Justice. “ Monopile Worries Mount: Grouted Joint Doubts Linger”. Neutral Citation Number: [ 2014] EWHC 1088 (TCC). April 11 th 2011.pdf 20. Wind Energy Update (2012). 1 st November 2013. Technology and Construction Court.com/ article/ 1217165/ prepared-new-technology-defects 23. 22 nd June 2010. (2011). http: / / vbn. Ref. “Monopile Failures Put Grout in Doubt”. http: / / proceedings.References ( 3) 18. Windpower Monthly (2010.com/ offshore/ monopile-failures-put-grout-doubt 24.com/ offshore/ monopile-retrofits-and-designs-going-forward-room-grout 25. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . Golightly GO-ELS Ltd.php?id2= 566&id= 104% 20&ordre= 1 21.stahlbau. EWEA 2011.ewea. Proc.Yde.org/ ew/ cases/ EWHC/ TCC/ 2014/ 1088. (2010). Serednicki. www. and Lochte-Holtgreven. Schaumann. “Monopile Retrofits and Designs Going Forward: Room for Grout?”. http: / / social.com/ turbine-supply-chain/ monopile-worries-mount-grouted-joint-doubts-linger 26.. L. (2011). Between : MT Højgaard a/ s [ Claimant] and E.windenergyupdate. Judgement Before: Mr.html?&no_cache= 1&L= 1&tx_tkinstpersonen_pi1% 5BshowUid% 5D= 14&tx_tkinstpersonen_pi1% 5Bpublika tionen% 5D= 1 19. S.. “Fatigue Life of High Performance Grout for Wind Turbine Grouted Connection in Wet or Dry Environment”. J.V. Justice Edwards-Stuart. November 2013.windenergyupdate.html Dr. Windpower Monthly (2010).ON Climate and Renewables UK Robin Rigg East and West Ltd.com/ article/ 1011507/ offshore-monopile-failure---solution-may-sight 22.. Van der Temple.bailii. Amsterdam. “Be Prepared For New Technology Defects”. March 18 th 2011. [ Defendants] . April 10 th 2012.windpoweroffshore. Wilke. F. Soerensen. R. EWEA 2011. www. Solving The Grout Problem” Proc..E. Queen’ s Bench Division. “Slip Joint.de/ 170. P. www. Westhof. “Offshore Monopile failure – A Solution May be I n Sight”.aau. Wind Energy Update (2011). November 2011. Case No: HT-12-148.org/ offshore2011/ programme/ info2. E.dk/ files/ 58115513/ Fatigue_Life_of_High_Performance_Grout_for_Wind_Turbine_Grouted_Connection_in_We t_or_Dry_Environment. A. http: / / social.unihannover.. edu: https: / / independent. “ I gnore The Geology at Your Peril” – Prof. 1991. BSc.R.edu/ ChristopherGolightly “You Pay for a Site I nvestigation .com/ pub/ 5/ 4b5/ 469 Twitter: @CRGolightly Academia. C. FGS. PhD. + 32 10 41 95 25 Mobile: + 44 755 4612888 Email: chris. Dr. [email protected] skype: chrisgolightly Linked I n: linkedin. John Burland.Whether You do One or Not” – Cole et al. Golightly. C. Belgium Tel. MI CE.Contact Details Dr. I mperial College. R. Golightly GO-ELS Ltd. 1300 Limal. – The Future For Monopile & Jacket Pile Connections – Developer & I nvestor Perspectives 27th October 2014 . 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