發(fā)布時(shí)間：2018-04-18 06:30

  本文選題：近海風(fēng)電 + 粘性土　； 參考：《西南交通大學(xué)》2014年碩士論文

【摘要】：隨著傳統(tǒng)化石能源對(duì)環(huán)境的影響日趨嚴(yán)重,風(fēng)能作為新型可再生能源得到了廣泛關(guān)注。其中,近海豐富的風(fēng)能資源掀起了近海風(fēng)電的發(fā)展熱潮。單樁式基礎(chǔ)是海洋風(fēng)電最常采用的基礎(chǔ)形式之一,國內(nèi)外許多學(xué)者開展了其在海洋環(huán)境內(nèi)荷載作用下的安全性研究。由于近海風(fēng)機(jī)在全壽命期內(nèi)可能要承受地震荷載、風(fēng)浪荷載及機(jī)械振動(dòng)等多種荷載作用,因而結(jié)構(gòu)安全需要滿足：1)風(fēng)機(jī)整體結(jié)構(gòu)自振周期在運(yùn)營年限內(nèi)避開葉片轉(zhuǎn)動(dòng)周期,避免產(chǎn)生共振；2)在外荷載作用下橫向變形滿足設(shè)計(jì)要求。本文主要研究了單樁式基礎(chǔ)在地震荷載作用下和長(zhǎng)期循環(huán)荷載作用下的動(dòng)力特性�；谏虾|海大橋風(fēng)電場(chǎng)場(chǎng)地條件,選取了3種地震波并采用NERA軟件分析了場(chǎng)地響應(yīng)特性。采用El Naggar提出的計(jì)算方法,結(jié)合ABAQUS軟件建立了非線性Winkler地基模型,計(jì)算了單樁式基礎(chǔ)在地震作用下的橫向變形特性。結(jié)合已有的試驗(yàn)資料,提出了我國沿海典型粘土的軟化系數(shù)經(jīng)驗(yàn)公式并建立了數(shù)據(jù)庫。在此基礎(chǔ)上,提出了新的粘性土剛度-阻尼退化模型,該模型采用修正彈簧-阻尼器并聯(lián)元件實(shí)現(xiàn)�；谔岢龅耐嘶Ｐ徒⒂�(jì)算模型,分析了單樁式基礎(chǔ)在長(zhǎng)期循環(huán)荷載下的自振頻率和橫向變形特性,并將計(jì)算結(jié)果與國內(nèi)外學(xué)者提出的控制標(biāo)準(zhǔn)進(jìn)行了對(duì)比。與規(guī)范的擬靜力法相比,本文的計(jì)算方法可較好的考慮動(dòng)力荷載的特性,并能較好的考慮長(zhǎng)期荷載對(duì)結(jié)構(gòu)的累積作用,可為以后的實(shí)際工程運(yùn)用提供參考。
[Abstract]:With the increasing impact of traditional fossil energy on the environment, wind energy as a new renewable energy has been widely concerned.Among them, offshore abundant wind energy resources set off offshore wind power upsurge.Single pile foundation is one of the most commonly used foundation forms for offshore wind power. Many scholars at home and abroad have carried out research on its safety under the load in marine environment.Since offshore fans may have to bear various loads such as earthquake load, wind wave load and mechanical vibration during their lifetime, the structural safety needs to meet the requirement of 1: 1) the free vibration cycle of the whole structure of the fan should avoid the blade rotation cycle in its operating life.The transverse deformation under external load meets the design requirements.In this paper, the dynamic characteristics of single pile foundation under earthquake load and long term cyclic load are studied.Based on the site conditions of Shanghai Donghai Bridge wind farm, three kinds of seismic waves were selected and the site response characteristics were analyzed by NERA software.The nonlinear Winkler foundation model is established by using the calculation method proposed by El Naggar and the ABAQUS software. The transverse deformation characteristics of single pile foundation under earthquake action are calculated.Based on the available experimental data, an empirical formula for softening coefficient of typical coastal clay in China is put forward and a database is established.On this basis, a new stiffness-damping degradation model of cohesive soil is proposed, which is implemented by a modified spring-damper parallel element.Based on the proposed degradation model, the natural vibration frequency and transverse deformation characteristics of single pile foundation under long-term cyclic load are analyzed, and the calculation results are compared with the control standards proposed by domestic and foreign scholars.Compared with the quasi-static method of code, the calculation method in this paper can better consider the characteristics of dynamic load and the cumulative effect of long-term load on the structure, which can provide a reference for the practical application in the future.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU473.1
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本文編號(hào)：1767193