海上风机钢管桩基础耐腐蚀性研究

发布时间：2018-02-16 23:04

本文关键词： 海上风机腐蚀机理腐蚀数学模型数值分析防腐优化设计　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：风机基础是|海上风机机组的重要组成部分，其作为永久性建筑长|期伫立在苛刻的海洋腐蚀环境中，防腐蚀设|计关系到风机|结构基础|的安全使用。在风机基础设计使用年限内只进行结构可靠性分析，却不考虑因|腐蚀引起|结构承载能|力的变化是非常危险的。迄今为止，海上风机钢管桩基础防腐问题一直没有得到很好的解决。鉴于此，本文以教育部博士点基金项目（20125522110004）和重庆市自然科学基金重点项目（cstc2013jjB3002）为依托，以上海东海大桥海上风电场项目为工程背景，在前人研究的基础上，采用理论分析及数值模拟等手段，对海上风机钢管桩基础耐腐蚀性进行了研究。主要研究内容及成果如下：（1）以东海大桥海上风电场为工程背景，分析了海上风机基础主要环境荷载计算方法及荷载组合，并对3MW级海上风机钢管桩基础进行了正常运行工况及极限荷载工况下荷载计算。从桩-土相互作用机理出发，采用P-y曲线法模拟桩土接触的非线性行为，并利用地层资料进行了计算，得到了风机钢管桩地基土体的P-y曲线数据，为腐蚀影响下风机钢管桩强度及稳定性的折减分析提供荷载数据和边界数据。（2）通过对海洋环境下钢结构的腐蚀类型及腐蚀机理进行分析，得出海上风机钢管桩基础腐蚀裂纹扩展是阳极溶解和表面膜破裂共同作用的结果，为研究海上风机钢管桩腐蚀速率发展规律及腐蚀对桩基结构强度和稳定性的影响奠定理论基础。（3）通过对现有海工钢结构腐蚀数学模型的分析，确定了符合海上风机钢管桩基础的均匀腐蚀数学模型为考虑防腐系统与腐蚀环境共同作用的非线性腐蚀模型。在此基础上，通过对土体材料及风机钢管桩本构模型的分析，建立了腐蚀条件下海上风机钢管桩基础的三维有限元模型，并分别对风机钢管桩的均匀腐蚀和局部腐蚀进行有限元模拟计算，得到了不同腐蚀形态下风机钢管桩强度及稳定性的折减规律。（4）综合模拟腐蚀分析结果，，对照海上风机钢管桩的常规防腐设计思路和防腐措施，提出了针对海上风机钢管桩结构工程特性的防腐优化设计方案，并对东海大桥海上风电场3MW风机钢管桩进行了优化方案详细设计，为海上风机钢管桩基础防腐设计提供参考依据。
[Abstract]:Fan foundation is an important part of offshore fan unit. As a permanent building, fan foundation stands in harsh marine corrosion environment for a long time. The anticorrosion design is related to the safe use of the fan's structural foundation. The structural reliability analysis is only carried out during the design life of the fan's foundation. So far, the corrosion problem of offshore fan steel pipe pile foundation has not been solved very well. This paper is based on the doctoral Program Project of the Ministry of Education, 20125522110004) and the key project of Chongqing Natural Science Foundation, CSTC2013jjB3002). Based on the engineering background of Shanghai Donghai Bridge Offshore Wind Power Project, and on the basis of previous studies, The corrosion resistance of offshore fan steel pipe pile foundation is studied by means of theoretical analysis and numerical simulation. The main contents and results are as follows:. 1) taking the offshore wind farm of Donghai Bridge as the engineering background, the main environmental load calculation method and load combination of offshore fan foundation are analyzed. The load calculation of steel pipe pile foundation of 3 MW offshore fan under normal operation condition and ultimate load condition is carried out. According to the pile-soil interaction mechanism, P-y curve method is used to simulate the nonlinear behavior of pile-soil contact. The P-y curve data of blower steel pipe pile foundation soil are obtained by using stratigraphic data, which provides load data and boundary data for the strength and stability reduction analysis of fan steel pipe pile under the influence of corrosion. 2) through the analysis of corrosion type and corrosion mechanism of steel structure in marine environment, it is concluded that corrosion crack propagation of offshore fan steel pipe pile foundation is the result of the joint action of anodic dissolution and surface film rupture. It lays a theoretical foundation for studying the development law of corrosion rate of offshore fan steel pipe pile and the influence of corrosion on the strength and stability of pile foundation. 3) by analyzing the existing mathematical models of corrosion of marine steel structures, a mathematical model of uniform corrosion in accordance with the foundation of offshore fan steel pipe piles is established as a nonlinear corrosion model considering the joint action of corrosion protection system and corrosion environment. Based on the analysis of soil material and constitutive model of fan steel pipe pile, the 3D finite element model of offshore fan pipe pile foundation under corrosion condition is established, and the uniform corrosion and local corrosion of fan pipe pile are simulated by finite element method. The reduction law of strength and stability of blower steel pipe pile under different corrosion forms is obtained. 4) synthetically simulates the corrosion analysis result, contrasts the conventional anticorrosive design thought and the anticorrosive measure of the offshore fan steel pipe pile, puts forward the anticorrosion optimization design plan according to the offshore fan steel pipe pile structure engineering characteristic. The optimization scheme of 3MW fan steel pipe pile in Donghai Bridge offshore wind farm is designed in detail, which provides a reference for the anticorrosion design of offshore fan steel pipe pile foundation.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU476

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