【作者】 武文杰；

【导师】 韩冰； 王元丰；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 桥梁在为社会提供出行便利的同时,在建设、运营维护直至拆除期间也增加了环境、社会、经济成本,导致其可持续性的下降。本文基于生命周期评价(Life Cycle Assessment, LCA)和生命周期成本(Life Cycle Cost, LCC)分析,考虑了其中的不确定性影响,采用定量评价的方法,综合桥梁对社会、经济和环境的影响来衡量桥梁全生命周期内的可持续性。进一步通过综合的方法结合环境影响和成本来进行可持续性评价,并使用多目标优化方法对桥梁运营维护策略做出了优化,以探索桥梁可持续性评价和生命周期管理的新途径。重点在以下方面开展了工作：(1)明确桥梁LCA的边界和内容的基础上,使用生态指标法建立桥梁LCA最终点破坏模型,并给出了计算公式。进而分析了清单数据不确定性产生的原因,以及误差在评价模型中的传递过程,并给出了LCA不确定性的计算方法。计算了案例桥梁的环境影响值,并分析了生命周期各个阶段、不同环境影响的特点以及形成的原因,通过统计方法计算出案例桥梁的LCA不确定性,得出了环境影响的概率分布。(2)分析了桥梁全生命周期成本(LCC)的构成,并给出了相应的计算公式。讨论了桥梁工程各项成本的不确定性来源及统计方法,得出各项成本的概率分布,建立了基于时间价值和不确定性的桥梁全生命周期成本计算模型,并建立了桥梁预防性维护成本和实质性维护成本的演化模型。(3)通过清单分析和矩阵运算,用社会支付意愿法核算出桥梁环境影响的货币价值,将桥梁环境影响和成本分析交集部分统一计算,得到统一量度值的桥梁可持续性评价结果；同时基于模糊数学理论建立了多指标输入的评价模型,可以评价桥梁设计或维护方案的综合可持续性。(4)考虑桥梁工程运营期时间跨度大的特点,结合LCA、LCC和结构时变可靠度,采用蒙特卡罗模拟得出桥梁运营阶段不同的维护策略在生命周期内造成的成本和环境影响变化,用帕累托最优的方法对桥梁预防性维护和实质性维护的策略进行了多目标优化,并对优化结果作出评价,进而讨论了其中的不确定性以及对桥梁可持续性的影响。(5)为了使评价工作紧密结合工程、易于操作,开发编制了桥梁可持续性量化评价系统软件,集成了所需的环境影响潜值、成本等数据库,利用统一的清单进行桥梁生命周期环境影响(LCA)和成本(LCC)的计算,可以实现对桥梁可持续性的单项或综合评价、方案比选、维护策略优化以及不确定性分析。更多还原

【Abstract】 In its life cycle, bridge can support transport, in the meanwhile, due to the activities of construction, maintenance and demolition, it can also bring some environmental and social impact, leading to a decreasing sustainability. In this paper, a quantitative evaluation method is adopted to measure the sustainability of bridge in its life cycle, from three aspects of society, environment and economy, mainly focusing on life cycle environmental impact and life cycle cost. By multi-objective optimization, the operation phase accounting for the longest life is optimized, exploring a new approach of sustainability assessment and process management on bridge engineering. The following work is mainly conducted:(1) Make clear of the system boundary and content of bridge life cycle assessment (LCA) and the calculation formula is given by Eco-indicator. In addition, the causes of uncertainty in the stage of life cycle inventory are analyzed, and the method of LCA based on uncertainty is presented. A case is studied to give the bridge’s environmental impact in different stages and the characteristics of different environmental impact are analyzed. Besides, the LCA uncertainty of the sample bridge is calculated by statistical method, and the probability distribution of the environmental impact is obtained.(2) Bridge life cycle cost (LCC) is divided into different sectors, and the calculation formula for each part is established. By discussing the uncertainty of LCC data sources and its statistical methods, the probability distribution of the cost is drawn. In addition, a bridge LCC model based on time cost and uncertainty is established, considering preventive maintenance cost and essential maintenance cost.(3) The bridge environmental impact is calculated in a monetary form by willingness to pay by using the integrated effect of matrix operation. Through a unified computing, the bridge environmental impact and cost are integrated, obtaining a measureable bridge sustainability assessment result. At the same time, based on the fuzzy mathematic theory, a model of single index output and multi-index inputs is established.(4) In consideration of the characteristic of bridge’s long operation period, combined LCA and LCC with time-dependent reliability, the paper investigates the effect of the maintenance strategies on LCA and LCC by Monte Carlo simulation. In addition, a multi-objective optimization of the strategies of preventive maintenance and essential maintenance is conducted based on Pareto Optimization. (5) The bridge sustainability quantitative assessment software is developed by integrating with the required environmental impact and cost database and using a unified inventory. This software can be used to assess the life cycle environmental impact and the life cycle cost of bridge separately, or assess its sustainability synthetically. Besides, it can also realize the functions of schemes comparison, maintenance strategies optimization and uncertainty analysis.更多还原