Luận văn Phân tích và so sánh kết cấu jacket 3 và 4 chân cho turbine gió ngoài khơi dưới sự ảnh hưởng của xói mòn.Luận văn Phân tích và so sánh kết cấu jacket 3 và 4 chân cho turbine gió ngoài khơi dưới sự ảnh hưởng của xói mòn.Luận văn Phân tích và so sánh kết cấu jacket 3 và 4 chân cho turbine gió ngoài khơi dưới sự ảnh hưởng của xói mòn.Luận văn Phân tích và so sánh kết cấu jacket 3 và 4 chân cho turbine gió ngoài khơi dưới sự ảnh hưởng của xói mòn.Luận văn Phân tích và so sánh kết cấu jacket 3 và 4 chân cho turbine gió ngoài khơi dưới sự ảnh hưởng của xói mòn.
Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos UNIVERSIDAD DE CANTABRIA Analysis and Comparison of The Behavior Between 3-Legged and 4-Legged Jacket Structure for Offshore Wind-turbine Influenced by The Scouring Effect Author: CAO ANH VU Supervisor: FRANCISCO BALLESTER Co-supervisor: JOKIN RICO Universitary Degree: Master in Construction Research, Technology and Management in Europe – Máster en Investigación, Tecnología y Gestión de la Construcción en Europa Santander, September 2017 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE LỜI CẢM ƠN Qua luận văn này, dòng tác giả muốn bày tỏ lòng biết ơn sâu sắc đến người nhiệt tình giúp đỡ, dạy, tạo điều kiện tốt suốt buổi đầu khóa học đến ngày hồn thiện luận văn Tác giả muốn bày tỏ lòng biết ơn chân thành đến thầy Francisco Ballester Muñoz thầy Jokin Rico Arenal, giáo sư hướng dẫn giám đốc phòng nghiên cứu phát triển công nghệ xây dựng INGECID – Khoa Xây Dựng – Đại học Cantabria (Tây Ban Nha), người định hướng đưa góp ý kịp thời cho tác giả suốt bốn tháng thực luận văn Lời cảm ơn chân thành xin gửi đến thầy ban điều hành khóa học, thầy giáo Daniel Castro, thầy giáo Jorge Rodriguez thầy giáo Pablo Pascual động viên giúp đỡ tác giả suốt trình học tập Tây Ban Nha Đan Mạch Tác giả không quên công ơn đội ngũ hai mươi giảng viên đến từ quốc gia Đức, Pháp, Đan Mạch, Bồ Đào Nha, Ý Tây Ban Nha, người tạo nên môi trường học tập làm việc chuyên nghiệp suốt khoảng thời gian năm vừa qua Tác giả xin dành tình cảm chân thành gửi đến anh chị em lớp Cao học khóa 2016-2017 kỹ sư/kiến trúc sư/nghiên cứu sinh cơng tác phòng nghiên cứu INGECID, đặc biệt hai người đồng nghiệp Silvia Suarez Marcos Cerezo, người sát cánh, động viên, hướng dẫn, bảo tận tình cho tác giả q trình cơng tác trung tâm INGECID Cuối xin dành lời cảm ơn sâu sắc tới gia đình, bạn bè bạn gái tác giả quê hương Việt Nam, người dõi theo nguồn động viên mặt vật chất lẫn tinh thần cho tác giả suốt trình học tập xa nhà VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE ACKNOWLEDGEMENTS I owe my deepest gratitude to my supervisors Professor Francisco Ballester Muñoz – Director of Engineering department - University of Cantabria (Spain) and Professor Jokin Rico Arenal – Director of INGECID Company – for all of the useful comments, leading ideas through the process of my final thesis I wish to thank, Professor Daniel Castro, Professor Jorge Rodriguez and Professor Pablo Pascual, the Master’s director and coordinators, who gave me continuous encouragement throughout one year of study in Spain and Denmark I would like to thank all Professors and Lectures, who are giving lectures in twenty modules of the “Construction research, technology, and management in Europe” master course for creating a professional working environment during the period of this master course also for all their favors given to me I also share the credit of my work with all my colleagues in the Master class as well as in INGECID Company, especially Silvia Suarez and Marcos Cerezo, because of their supports and advice while I was doing my internship Last but not least, I must express my very profound gratitude to my parents and my girlfriend in Viet Nam for all their unconditional love they gave to me Without them, I would not be able to achieve or enjoy these successes VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE TÓM TẮT NỘI DUNG LUẬN VĂN Phân Tích Và So Sánh Ứng Xử Của Hệ Giàn Thép Chân Và Chân Cho Tháp Turbine Gió Ngồi Khơi Dưới Sự Ảnh Hưởng Của Xói Mòn Trải qua trình ba mươi năm phát triển, ngành công nghiệp lượng biết đến mũi nhọn công nghiệp tiên tiến giới Trong đó, cơng nghệ lượng xanh, cụ thể lượng gió ngồi khơi mang đến nguồn lượng sạch, dồi an toàn cho nhân loại Tuy nhiên, kỹ sư muốn đưa turbine gió xa khơi, họ phải đối mặt phải nhiều thử thách từ thiên nhiên Do đó, việc nghiên cứu đầy đủ cách kết cấu ứng xử trước điều kiện tự nhiên khắc nghiệt vấn đề cấp thiết Trong khn khổ luận án, hệ thống móng cọc thép dài 35m, đường kính 2.5m, chiều dày 5cm lựa chọn để truyền toàn tải trọng hệ thống jacket wind turbine cao 161.6m xuống lòng biển Luận văn tập trung nghiên cứu phân tích ứng xử hai loại jacket chân chân trạng thái cực hạn với tượng xói mòn biến đổi lòng biển suốt trình hoạt động hệ thống Sự chuyển vị ứng suất Von-Mises kết cấu đem so sánh, nhằm đưa nhìn khái quát cho loại jacket Kết nghiên cứu có ích cho việc lựa chọn sơ hệ jacket phương án phòng ngừa thích hợp cho tượng xói mòn biến động lòng biển tương lai ABSTRACT Analysis and Comparison of The Behavior Between 3-Legged and 4-Legged Jacket Structure for Offshore Wind-turbine Influenced by The Scouring Effect Throughout the period of thirty years, the energy industry is known as one of the most developing fields in the world Moreover, the wind energy industry in objective and the offshore wind power in subjective is one of the main eco-friendly sources of energy for humankind Due to the needs of applicability and economic efficiency, the larger size of offshore wind turbine structure needs to go to the deeper water However, the further we went to the ocean, the more complicated states of environment we got so that we need to fully analyze and comprehend the behavior of the support structures against the severe or extreme weather conditions During this study, steel pile foundation, which has a penetration length of 35m, the diameter of 2.5m and 5cm of wall thickness, is a primary choice to anchor the jacket structure and wind turbine with 161.6m total height to the sea floor This study analyzed the offshore jacket’s behavior within the Ultimate limit state (ULS), the scour and sand waves in general, supports for the 5MW offshore wind turbine These result will provide an overall view between different types of the structure against the scour and uneven sea bed level caused by sand waves The deformations and the Von-Mises stresses of the 3-legged and the 4-legged jacket were compared, in order to fulfill the gap of understanding these two types of support structures The study will be useful for considering a suitable jacket and optimal scouring prevention methods to be executed for the future project VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE TABLE OF CONTENTS CHAPTER INTRODUCTION 1.1 Overall Review of Offshore Wind Turbines 1.2 Motivation and Objective of the study 10 1.3 Tasks of the Thesis 10 1.4 Structure of the Document 11 1.5 The Regulation and Software used 11 CHAPTER THE BASIC OF OFFSHORE WIND TURBINE STRUCTURES 12 2.1 Introduction 12 2.2 Support Structure of Offshore Wind Turbine 12 2.2.1 Monopile 12 2.2.2 Gravity-Based Structure (GBS) 13 2.2.3 Tripod 14 2.2.4 Jacket Structure 14 2.2.5 Floating Structure 15 2.3 The Scouring Predictions and Prevention Methods for Jacket Structure 16 2.3.1 The scouring phenomenon 16 2.3.2 The Method of Predicting the Scouring Effect 17 2.3.3 The Consideration of Sand Wave 19 2.3.4 The Method of Preventing the Scouring Effect 20 2.4 Wind Conditions 24 2.4.1 Mean Wind Speed 25 2.4.2 Wind Speed Profiles 25 2.4.3 Distribution of Wind Pressure on the Structure 26 2.5 Waves 28 2.5.1 Basic Waves Characteristic 28 2.5.2 Wave Modeling 29 2.6 Currents 31 2.7 Combine Wave and Current by Morison’s Load Formulas 31 2.8 Sand Wave 32 2.9 Marine Growth 33 2.10 Ultimate Limit States (ULS) and Load Combinations 33 2.11 Soil-Structure Interaction 34 2.11.1 Soil reaction for piles under axial compression 34 2.11.2 Soil reaction for piles under lateral loads 35 CHAPTER GENERAL INFORMATION OF THE JACKET STRUCTURES 39 VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE 3.1 Introduction 39 3.2 Specific Environmental Conditions and Design Load Cases 39 3.2.1 Wind, Wave, and Current Conditions 39 3.2.2 Soil Conditions 42 3.2.3 Scouring Conditions 42 3.2.4 Sand Wave Model 43 3.2.5 The Meteorological – Oceanographic Parameter 44 3.2.6 ULS Load Combinations 44 3.2.7 The Wind-Wave Misalignment Models 44 3.3 Geometry of the specific 3-Legged Jacket and the 4-Legged Jacket Structure 46 3.3.1 The Chosen Wind Turbine 46 3.3.2 The Model of 3-Legged Jacket 47 3.3.3 The Model of 4-Legged Jacket 48 3.3.4 The Model of Steel Pile Foundation 49 3.3.5 The Initially Analysis of Von-Mises Stress 51 CHAPTER RESULT OF THE ANALYSIS AND THE DISCUSSION BETWEEN SCOURING AND SAND WAVE TO THE NATURAL FREQUENCY OF JACKET STRUCTURES 53 4.1 Introduction 53 4.2 The Result from the Natural Frequency Analysis 53 CHAPTER RESULT OF THE ANALYSIS AND DISCUSSION BETWEEN SCOURING AND SAND WAVE TO THE BEHAVIOUR AND THE STRESSES OF THE JACKET STRUCTURES 55 5.1 Introduction 55 5.2 The Relationship between Scouring Effect, Stresses and Displacement of Jackets 55 5.2.1 Comparing the Stresses of the Jackets under the the Scouring 55 5.2.2 Comparing the Displacement of the Jackets under the Scouring 57 5.3 The Sand Wave 58 CHAPTER CONCLUSIONS AND FUTURE WORKS 60 6.1 Conclusions 60 6.2 Future Works 60 References…………….…………….…………….…………….…………….…………….…………….…………….………61 APPENDIX A 63 APPENDIX B 67 VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE LIST OF FIGURES Figure 1-1: Cumulative and annual offshore wind installation (MW) - (WindEurope, 01/2017) Figure 1-2: Support structure for offshore wind turbine (WindEurope, 01/2017) Figure 1-3: Offshore wind substructure designs for varying water depths (Dvorak, 2017) 10 Figure 2-1: Monopile structure (Garrad Hassan and Partners Ltd) 12 Figure 2-2: Monopile installation (Lapke, 2015) 13 Figure 2-3: Gravity-based foundation (Garrad Hassan and Partners Ltd) 13 Figure 2-4: Tripod Structure (Garrad Hassan and Partners Ltd) 14 Figure 2-5: Pre-fabricate and transportation of tripod structures 14 Figure 2-6: Jacket support structure 15 Figure 2-7: The main construction stages 15 Figure 2-8: Floating support structure for offshore wind turbine 16 Figure 2-9: Scouring effect around a vertical pile 16 Figure 2-10: Scouring effect 17 Figure 2-11: Scour formation around jacket foundation G2: August 2011 to February 2012 (BOLLE, et al., 2012) 19 Figure 2-12: The phase, amplitude and wave length of natural sand waves vary in space (Berg & Damme, 2004) 20 Figure 2-13: The long lasting protection system (DHI team) 20 Figure 2-14: Typical scour protection design (PETERS & WERTH, 2012) 21 Figure 2-15: The Geotextile containers solution 21 Figure 2-16: The installation of scour protection system in Ireland (2011) 22 Figure 2-17: Filter Unit protects wind turbine foundation (KYOWA) 22 Figure 2-18: Fauna and flora around RFU system 22 Figure 2-19: Scour Control System (SSCS) 23 Figure 2-20: Concrete mattress installation 23 Figure 2-21: The scour prevention system by using recycled rubber tire 24 Figure 2-22: The installation of rubber derivative system 24 Figure 2-23: Influence of the wind turbine to wind speed and air pressure (Veritas & Laboratory, 2002) 26 Figure 2-24: Definition of water levels 28 Figure 2-25: Regular traveling wave properties 29 Figure 2-26: Ranges of validity for various wave theories (Chakrabarti, 1987) 29 Figure 2-27: Characteristics of offshore sand bed forms 33 Figure 2-28: The data indicate for marine growth profile 33 Figure 2-29: Partial safety factors for loads γf 34 Figure 2-30: Design load cases 34 Figure 2-31: The p-y curves applied at nodal point in beam-column representation of pile 36 Figure 2-32: Coefficient as functions of friction angle 37 Figure 2-33: Initial modulus of subgrade reaction k as function of friction angle 37 Figure 3-1: The equivalent wind force from the tower and blades 40 Figure 3-2: The wave and current force for 4-legged jackets exported from EXCEL 40 Figure 3-3: The wave and current moment for 4-legged jacket exported from EXCEL 40 Figure 3-4: Wave and current load table of 4-legged jacket exported from Midas Software 41 Figure 3-5: Wave and current load table of 3-legged jacket exported from Midas Software 41 Figure 3-6: The Soil Properties 42 Figure 3-7: Example of scouring models 42 Figure 3-8: The sand wave model type 43 VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE Figure 3-9: The sand wave model type 43 Figure 3-10: The sand wave model type 43 Figure 3-11: The direction of the wind, wave for 4-legged jacket structures 44 Figure 3-12: The direction of the wind, wave for 3-legged jacket structures 44 Figure 3-13: The Models of the Study taking into account the Wind-Wave Misalignment, Scouring and Sand Wave Effect 46 Figure 3-14: The Gross Properties Chosen for the NREL 5-MW Baseline Wind Turbine 47 Figure 3-15: The Basic Estimation for Jacket Level 47 Figure 3-16: The Transition and Tower Base of 3-Legged Jacket 48 Figure 3-17: The Lateral View of 3-Legged Jackets Offshore Wind Turbine Structure 48 Figure 3-18: The Top View of 3-Legged Jackets Offshore Wind Turbine Structure 48 Figure 3-19: The Lateral View of 4-Legged Jackets Offshore Wind Turbine Structure 49 Figure 3-20: The Top View of 4-Legged Jackets Offshore Wind Turbine Structure 49 Figure 3-21: The Modulus of Subgrade Reaction 51 Figure 3-22: The Comparison of subgrade modulus reaction between clay and sand 51 Figure 3-23: Comparison of maximum Von-Mises stresses between non-scour models of 3-legged and 4-legged jackets 52 Figure 4-1: The allowable range for structure natural frequencies supports 5MW wind turbine 53 Figure 4-2: The natural frequency of jackets under scouring effect 54 Figure 4-3: The effect of sand wave to the natural frequency 54 Figure 5-1 Maximum Von-Mises Stress of 3-Legged Jackets 55 Figure 5-2: Maximum Von-Mises Stress of 4-Legged Jackets 56 Figure 5-3: The Comparison of Maximum and Minimum Von-Mises Stress between 3-Legged and 4-Legged Jackets 56 Figure 5-4: Maximum Deformation of 3-Legged Jacket during the Scouring 57 Figure 5-5: Maximum Deformation of 4-Legged Jacket during the Scouring 57 Figure 5-6: Comparing the Maximum and Minimum Deformation between Types of Jacket under Scouring Effect 58 Figure 5-7: Von-Mises Stresses and Deformations of 3-Legged Jackets within the Sand Waves 58 Figure 5-8: Von-Mises Stresses and Deformations of 4-Legged Jackets within the Sand Waves 59 Figure 5-9: The Maximum of Von-Mises Stresses and Deformations between 3-Legged and 4-Legged Jackets………………………………………………………………………………………………………………….59 VU CAO ANH P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE CHAPTER INTRODUCTION 1.1 Overall Review of Offshore Wind Turbines Throughout the period of thirty years, the energy industry is known as one of the most developing fields in the world Moreover, one of the eco-friendly methods of generating energy is the offshore wind turbine Based on the annual report The European Offshore Wind Industry in January 2017 showed that the Europe’s additive installed offshore wind capacity at the end of 2016 claimed to 12631 MW with the number of wind turbine overcome 3589 wind turbines There is a total of 81 offshore wind farms in 10 different countries in Europe (WindEurope, 01/2017) Figure 1-1: Cumulative and annual offshore wind installation (MW) - (WindEurope, 01/2017) Also, the pie graph (Figure 1-2) besides showed that the majority of the support structure for offshore wind turbines are monopile structures with 80.8% - 3354 foundations It can be seen that the market of wind energy is increasing rapidly However, the deep water locations are not invested as much as other foundation types Thus, this thesis will study further for the jacket structures Before going further into the study, there is a need of overall review between each support structures in order to provide a wide scope of the offshore wind turbine industry In general, the principal function of supporting structure is to hold the wind turbine in balance during every state of circumstances Moreover, there are several types of foundation concepts as well as the ways to distinguish each structure VU CAO ANH Figure 1-2: Support structure for offshore wind turbine (WindEurope, 01/2017) P a g e | 85 MASTER IN COSTRUCTION RESEARCH, TECHNOLOGY AND MANAGEMENT IN EUROPE The Result Table for Subgrade Modulus Reaction For 1m-Scour Models Elevation Soil Depth (m) Thickness (m) B (m) φ Cu (kN/m2) γ (kN/m3) sc sγ 0.4