【作者】 彭建新；

【导师】 邵旭东；

【作者基本信息】 湖南大学 ， 桥梁与隧道工程， 2009， 博士

【摘要】 桥梁等基础设施工程的基于寿命周期成本的全寿命设计理论和方法是近年来国内外工程界普遍关注的研究课题,在国内的研究尚处于起步研究阶段,工程应用更少。桥梁全寿命设计方法研究具有重要的学术意义和工程价值。在综述国内外相关文献的基础上,对桥梁全寿命优化设计方法的相关问题进行了深入研究。开展了如下研究工作:(1)基于现有的碳化深度预测模型,利用最新的气候变化数据,改进了受碳化腐蚀的预应力混凝土板梁的强度和开裂时变可靠度模型,计算了不同CO2浓度和不同腐蚀环境下预应力混凝土结构的失效概率和平均腐蚀损伤比例,比较了不同的耐久性措施和裂缝宽度准则对混凝土碳化损伤比例的影响。参数敏感性分析得到了进行时变可靠度分析的主要影响因素;(2)提出了基于概率的间接维护成本模型,使用基于改进的事件树模型,验证了间接维护成本模型的有效性;(3)提出了时变可靠指标和状态指标作为桥梁性能的定量评估指标,推导了桥梁维护策略-寿命周期成本-桥梁时变性能指标之间的相互关系,建立了多目标的组合维护优化模型,基于粒子群优化算法,得到了桥梁结构服役期内的最优维护策略;(4)提出了基于构造措施和设计细节的桥梁全寿命设计方法的体系框架和实施步骤,比较了全寿命优化设计方法和现有设计的联系和不同,结合试验桥的设计实践和基于全寿命成本桥梁车道数决策分析,验证了桥梁全寿命设计方法的合理性。更多还原

【Abstract】 In recent years, life-cycle cost-based bridge whole-life optimum design method for infrastructure engineering, such as bridge, building, etc, has become a hot research topic in engineering field in home and abroad. Its research in home is still in beginning stage. Moreover, its use in engineering practice is absolutely fewer. Consequently, the work on bridge whole-life design method in this paper has an important theoretical meaning and engineering values.Based on the state-of-the-practice and state-of-the-art of the literature reviews, the related problems for bridge whole-life design methodology have been systematically studied. Hence, the work was summarized as follow:(1) Based on the corrected carbonation depth prediction model, the present study described how climate change predicted increases in CO2 levels will affect carbonation-induced corrosion damage and safety loss to prestressed concrete structures using the latest CO2 emission scenarios. The time-dependent structural reliability analysis of prestressed concrete bridge deck will the predict probability of corrosion initiation, mean propotion of corrosion damage and probability of structural collapse over the next 100 years considering several IPCC atmospheric CO2 emission scenarios and various corrosive environments. The influence of durability design specification and crack width on the mean proportion of corrosion damage was analyzed. Parameter sensitivity analysis was used to obtain the important influencing factors for time-dependent structural reliability.(2) The present study presented probabilistic whole-life cost calculation models. The modified event-tree modelling was used to demonstrate the effectiveness of the developed indirect maintenance cost models.(3) The present paper proposed the reliability index and condition index as indicators of bridge performance and deduced the interaction of maintenance interventions– life-cycle cost– bridge time-dependent performance. Based on the Particle Swarm Optimization (PSO), the present study developed multi-objective combinative maintenance optimization hybrid model to optimize the optimal combined maintenance interventions that corresponds to the minimal life cycle cost and maximum of reliability index and condition index in service time.(4) The present study developed the systematic framework and flowchart for whole-life optimum design method based on structural configuration and design details, and compared the differences and relationships between the whole-life design and conventional design method. The design work on an example bridge and the whole-life cost based bridge lane decision were employed to demonstrate the reasonability of bridge whole-life optimum design method.更多还原