本文選題：近海風(fēng)機　切入點：傘式吸力錨基礎(chǔ)（USAF）　出處：《中國海洋大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：近海風(fēng)力發(fā)電是未來國家風(fēng)電能源戰(zhàn)略的核心，風(fēng)機基礎(chǔ)作為海洋構(gòu)筑物，長期面臨復(fù)雜海況和海底地質(zhì)活動的考驗，其在風(fēng)、浪、流等荷載聯(lián)合作用下的穩(wěn)定性分析成為風(fēng)電設(shè)計面臨的巨大挑戰(zhàn)�，F(xiàn)役的海上風(fēng)機基礎(chǔ)大都存在波浪對基礎(chǔ)周邊海床沖蝕嚴重，水平承載力在循環(huán)荷載下衰減快，安裝施工對海底環(huán)境擾動大等弊端，適于近海風(fēng)電場建設(shè)的新型風(fēng)機基礎(chǔ)型式迫切需要提出，風(fēng)機基礎(chǔ)結(jié)構(gòu)選型和設(shè)計成為影響大容量（MW級）、大規(guī)模風(fēng)電開發(fā)研究的熱點問題。本論文基于已有風(fēng)機基礎(chǔ)存在的弊端，設(shè)計提出了一種新型傘式吸力錨基礎(chǔ)（USAF），并通過理論分析、模型試驗、數(shù)值模擬等手段較系統(tǒng)的研究了USAF基礎(chǔ)的承載特性和動力響應(yīng)問題，運用海床土臨界液化孔壓比準則，構(gòu)建了USAF基礎(chǔ)的災(zāi)變控制監(jiān)測預(yù)警體系。具體研究工作如下： 1、以黃三角典型近海沉積環(huán)境與水動力特征為例，指出近海風(fēng)機基礎(chǔ)結(jié)構(gòu)選型和承載性能研究的重要性，進而提出了自主設(shè)計的傘式吸力錨基礎(chǔ)，并對USAF基礎(chǔ)的設(shè)計原理、結(jié)構(gòu)優(yōu)勢、沉貫機理、安裝方法等進行了詳細的說明。 2、運用極限分析原理對USAF基礎(chǔ)的水平承載特性展開分析，重點研究了各破壞區(qū)土體許可滑動狀態(tài)和許可速度場，通過對土體破壞機制和破壞區(qū)許可速度場的建立，推導(dǎo)了內(nèi)部能量耗散率和外力功功率表達式，繼而提出了USAF基礎(chǔ)的水平極限承載三維上限解法。通過算例將上限解與有限元模擬結(jié)果對比，證明了上限解法在求解USAF基礎(chǔ)水平極限荷載中的合理性。 3、通過室內(nèi)土箱試驗分析了USAF基礎(chǔ)在水平靜力加載、水平循環(huán)加載和豎向拉拔荷載下的錨-土相互作用規(guī)律。模擬了USAF在水平低頻荷載和一次風(fēng)暴潮作用后錨體的變位響應(yīng)，指出錨枝對動力荷載激勵下的錨體變形具有抑制作用。發(fā)現(xiàn)并闡述了USAF在上拔過程中的“分段現(xiàn)象”，提出了一種確定USAF基礎(chǔ)極限抗拔荷載的動力學(xué)搜索方法，并得到驗證。 4、使用ANSYS軟件分析了除風(fēng)荷載之外的波浪荷載、地震荷載和冰荷載等海洋動力載荷對海上風(fēng)機USAF基礎(chǔ)動力承載特性的影響。重點分析了主筒、筒裙、錨枝的不同模態(tài)振型和振動規(guī)律，討論了0～130Hz外荷載激勵作用下USAF結(jié)構(gòu)的諧響應(yīng)狀況，基于功率譜密度（PSD）法分析了波浪荷載作用下USAF結(jié)構(gòu)的振動響應(yīng)，研究了地震荷載和冰荷載兩類隨機荷載對USAF基礎(chǔ)結(jié)構(gòu)振動的影響。 5、依據(jù)Geo-Studio軟件在巖土非線性分析中的優(yōu)勢，采用擬靜力法對風(fēng)浪荷載下USAF周圍地基土變形及破壞模式進行了有限元模擬，，模擬發(fā)現(xiàn)土體內(nèi)部最大剪應(yīng)力發(fā)生在錨趾轉(zhuǎn)動區(qū)和錨枝下壓區(qū)，并結(jié)合土體內(nèi)部剪應(yīng)力應(yīng)變分布對主筒和筒裙轉(zhuǎn)動點的位置進行了分析。最后，將USAF基礎(chǔ)與常規(guī)吸力錨基礎(chǔ)進行同等水平荷載下的地基土變形比較，證明了新型USAF基礎(chǔ)的結(jié)構(gòu)承載優(yōu)勢。 6、從海床土微觀結(jié)構(gòu)入手，綜合考慮滲流場和應(yīng)力場的耦合作用，構(gòu)建了海床土液化破壞的重正化群模型，闡述了飽和海床土宏觀液化與微觀強度的定量關(guān)系，提出了海床土臨界液化孔壓比概念，繪制了不同土質(zhì)海床的臨界液化判別準則表，并對其影響因素進行了分析，準則對USAF基礎(chǔ)的災(zāi)變控制監(jiān)測預(yù)警具有重要意義。 7、介紹了USAF基礎(chǔ)智能監(jiān)測方法和預(yù)警系統(tǒng)的實現(xiàn)過程，通過孔壓傳感器與錨體的組合設(shè)計，使得海床土臨界液化孔壓比準則在判別風(fēng)機基礎(chǔ)穩(wěn)定性中得以應(yīng)用。監(jiān)測過程中主筒側(cè)壁和彈性盒內(nèi)布設(shè)的孔壓傳感器分別采集錨體周圍分層地基土的實時孔壓數(shù)據(jù)，在數(shù)據(jù)處理上，引入模糊判別因子對監(jiān)測孔壓值進行分析，一旦孔壓值超過臨界液化孔壓，系統(tǒng)就會發(fā)出報警信號，論文最后對監(jiān)測預(yù)警系統(tǒng)的工作原理和運作程序進行了說明。
[Abstract]:Offshore wind power is the core of the future national energy strategy of wind power, wind turbine foundation as the marine structures, facing complex sea conditions and seabed geological activity test, in the wind, wave, flow and stability analysis under the combined action of load has become a huge challenge facing the wind power design. The most active offshore wind turbine foundation there are waves on the basis of the surrounding seabed erosion is serious, fast decay under cyclic loading capacity, the installation of construction defects undersea environment disturbance, a new fan base type is suitable for the construction of offshore wind farms is an urgent need to put forward, the selection and design of wind turbine foundation become large capacity (MW), a hot issue in the research of mass the development of wind power. The drawbacks of existing wind turbine based on the design, proposed a new umbrella type suction foundation (USAF), and through theoretical analysis, model test, numerical simulation A systematic study of the bearing characteristics and dynamic response of USAF foundation is carried out. Based on the criterion of pore water pressure ratio of seabed soil, a monitoring and early warning system for USAF based disaster control is constructed.
1, in the Yellow River Delta typical coastal sedimentary environment and hydrodynamic characteristics as an example, points out the importance of offshore wind turbine foundation structure selection and bearing performance research, and then puts forward the umbrella type suction foundation is designed, and the design principle of USAF based structure, penetration mechanism and installation method in detail description.
2, analyze the application level of USAF based on the principle of limit analysis of bearing characteristics, focusing on the soil damage area license and license sliding state velocity field, through the establishment of soil failure mechanism and failure zone permit velocity field, the internal energy dissipation rate and external power are deduced, and then puts forward the three-dimensional bearing upper limit solution the level limit of USAF foundation. By contrast with the upper bound solution of finite element simulation results, proved the rationality of upper limit solution based on USAF level for limit load.
3, through indoor soil box experiments of USAF based on horizontal static loading, cyclic loading and the law of horizontal vertical pullout loads of anchor soil interaction. The simulation of USAF in low load and a storm surge after the anchor body displacement response, pointed out that the anchor branch on the dynamic load under the excitation of the anchor body the deformation has inhibitory effect. And the USAF in the pulling out process of "block phenomenon", proposed a USAF based dynamic determination of ultimate pullout load search method, and verified.
4, the use of ANSYS software to analyze the wave load in the wind load the seismic load and ice load and dynamic load bearing characteristics of marine influence on offshore wind turbine based on USAF power. Focus on the analysis of the main cylinder, Tongqun, different vibration modes and vibration law of anchor branches, discussed the status of response of USAF structure harmonic function 0 to 130Hz under external loads, based on power spectral density (PSD) method to analyze the vibration response of USAF structures under wave loading, studied the effect of seismic load and ice load of two stochastic load on USAF based structural vibration.
5, based on the advantage of Geo-Studio software in the nonlinear analysis of rock and soil, using the pseudo static method of foundation soil under wind and wave loads around USAF deformation and failure model of finite element simulation, simulation of soil maximum shear stress occurs in the anchor and anchor toe rotation area under branch pressure area, and combined with the soil shear stress the strain distribution of the main cylinder and the skirt of the rotation point position were analyzed. Finally, the USAF based and conventional suction anchor compare equal deformation of soil under horizontal load, proved that the structure of the new USAF foundation bearing advantages.
6, starting from the seabed soil microstructure, considering the coupling of seepage field and stress field, construction damage liquefaction of seabed soil renormalization model, describes the quantitative relationship between macro and micro liquefaction strength of saturated soil, the soil critical liquefaction pore pressure ratio concept, drawing on different soil the seabed critical liquefaction criterion, and analyzes its influencing factors, has an important significance criterion for USAF based disaster control monitoring and early warning.
7,浠嬬粛浜哢SAF鍩虹鏅鴻兘鐩戞祴鏂規(guī)硶鍜岄璀︾郴緇熺殑瀹炵幇榪囩▼,閫氳繃瀛斿帇浼犳劅鍣ㄤ笌閿氫綋鐨勭粍鍚堣璁

本文編號：1596601