节点文献
桥梁维修全寿命经济分析与优化的理论框架研究
A Theoretic Frame on Life-Cycle Economic Analysis and Optimization in Bridge Maintenance Decision
【作者】 曹明兰;
【导师】 黄侨;
【作者基本信息】 哈尔滨工业大学 , 桥梁与隧道工程, 2007, 博士
【摘要】 由于交通量、车辆荷载的增加和结构本身的自然老化,在我国近20年来建造的大量公路桥梁中,缺损与老化桥梁数量不断增加,亟待维修改造的桥梁数量日益增多。然而,受国家财力所限,能够投入的资金远不能满足需要。因此,如何合理分配使用有限的资金,以确保公路畅通与桥梁安全,怎样进行桥梁维修决策的经济分析与优化,是摆在我国桥梁界面前的一个非常迫切的问题。一直以来,关于桥梁维修经济分析与优化,国内外进行了不懈的探索,取得了一些成果。但是由于这方面的研究涉及桥梁工程、技术经济学、计算机技术和优化技术等多领域的知识,加上桥梁结构系统本身的复杂性以及目前对桥梁全寿命使用期内的各种不确定性影响因素缺乏全面深入的掌握,致使桥梁维修经济分析与优化的理论研究方面尚处于基础性探索阶段。在此背景下,本文就桥梁管理维修经济分析与优化的理论与方法展开研究,并初步建立了桥梁维修全寿命经济分析与优化的基本理论框架。根据文献检索,这样的框架在国内外都是首次提出的,论文所建立的模型和所提出的计算公式与分析方法比目前国外在维修分析中采用的更为简单有效。本论文所建立的这种理论框架,是一种新的探索与尝试,它将促进该方面研究的进一步发展。该理论框架具体包括以下内容和创新性成果:1.针对混凝土桥梁结构,建立了多种线性或非线性的劣化模型,建立了这些模型简单统一的计算公式;结合我国实际,给出了基于桥梁可靠度或状况评估值的线性劣化模型的具体参数。桥梁的结构形式繁多,不同的结构存在不同的劣化模式。论文建立的这些劣化模型,为不同劣化模式匹配合理的劣化模型提供更大的选择余地,而准确的桥梁劣化预测模型是维修优化工作的基础。2.建立了多种桥梁维修效果模型及其简单统一的指标计算公式。各种桥梁维修措施产生的维修效果是不同的,因此,建立其维修效果模型,是分析维修效果和进行维修优化的基础。本论文由于采用了所建立的生效函数法,从而使得所建立的维修效果模型既简单合理又便于进行桥梁维修全寿命经济分析与优化。3.针对混凝土桥梁结构,建立了有预防维修时的桥梁劣化模型,通过建立不同维修模式与无预防维修时的不同劣化模式组合后的各种情形的指标计算公式,为桥梁维修全寿命经济分析与优化打下了基础。4.提出了桥梁维修优化的经济分析方法。通过提出合理收益法,进一步给出了用于桥梁维修方案比较评价与优化的一系列经济指标;根据经济学原理,建立了桥梁维修的动态维修成本计算公式。经济学中的投资决策问题已有成熟的评价指标与评价方法。桥梁维修优化有四个主要目标:维修成本、桥梁使用寿命、桥梁状况或可靠度,这些目标会互相制约,需对其统筹兼顾。本论文运用合理收益法将桥梁使用寿命、桥梁状况和可靠度以货币收益的形式体现出来,从而使决策者得以用一种新的更加合理的方法对桥梁维修方案进行全寿命经济分析与优化,并可以移植更多的经济学概念与方法到桥梁维修优化中。5.提出了桥梁维修的基本优化方法与组合优化方法。通过建立首次重大维修时间、预防维修次数和维修效果指标等的计算公式并给出其计算步骤,提出了预防维修的基本优化方法;提出了结合型和叠加型桥梁维修组合优化方法,建立了它们的指标计算公式,并结合例子计算了它们的维修效果参数,给出了两种组合优化方法的优化步骤;提出了重大维修与预防维修的组合优化方法,分别给出了它们的指标计算公式以及优化例子。通过同时考虑重大维修与预防维修,既有利于改变人们忽视预防维修的传统观念,又使论文所建立的桥梁维修全寿命经济分析与优化的理论框架更完整更实用。6.基于上述成果,研究开发了桥梁维修全寿命经济分析与优化程序BMOP(Bridge Maintenance Optimization Program),并结合实际维修措施给出了运用该程序进行桥梁维修全寿命经济分析与优化的算例,初步展现出所建理论框架的应用价值。
【Abstract】 Among great quantity of highway bridges built in China in recent 20 years,there are increasing damaging or aging bridges because of increasing of traffic and vehicle load as well as natural aging of bridge structure itself. However,the money that can be used to repair these bridges is far lower than the needed money since China is still a developing country and the money is limited. Therefore,how rationally to allocate and use the limited money in order to ensure running smoothly of highway and safety of bridges and how to carry out economic analysis and optimization in bridge maintenance decision are urgent problems with which Chinese bridge field must be faced. For economic analysis and optimization in bridge maintenance decision,there are lots of researches and achievements home and overseas for many years.However,theoretic study on economic analysis and optimization in bridge maintenance decision is still a primary and fundamental stage because of such research involving in multi-field knowledge such as bridge engineering,economics,computer technology and optimization technology,complex of bridge structure itself and lack of deep comprehension for various uncertainties during total lifetime of bridges. Based on such background,the theory and methods of life-cycle economic analysis and optimization in bridge maintenance decision are studied in this paper.The frame of a basic theory on life-cycle economic analysis and optimization in bridge maintenance decision is constructed. The frame is firstly presented in homeland and overseas according to literature indexing. The established models and the presented formulae and analysis methods in the paper are far more simple and efficient than those foreigners have been adopting in maintenance analysis. The theoretic frame built in the paper is a new exploring and attempt and will facilitate development in this aspect of study. It includes main contents and innovative achievements as follows:1. Various linear and non linear deterioration models for concrete bridge structuers are presented and simple and unified computing formulae of these models are given. Combined with Chinese standards,values of parameters of linear deterioration models of bridge reliability and estimated condition state are given. There are many categories of bridge structure and different bridge structures have different deterioration models. The deterioration models built in the paper provide more selection for different deterioration modes’matching rational deterioration models. Accurate prediction of bridge deterioration is a basis of bridge maintenance optimization.2. Multi-categories effect models of bridge maintenance are built and simple and unified index computing formulae of these models are given. Maintenance effect produced from various bridge maintenance actions varies with each other. Therefore,to establish various deterioration effect models is a foundation of maintenance effect analysis and optimization. The maintenance effect models established in the paper are simple and rational for the presented validity functions are used. By help of these models,it is easy to carry out life-cycle economic analysis and optimization in bridge maintenance decision.3. Bridge deterioration models with preventive maintenance are built for concrete bridge structuers. Establishment of indexes computing formulae of various combining cases between different maintenance modes and different deterioration modes without preventive maintenance provides a base for life-cycle economic analysis and multi-objective optimization in bridge maintenance decision.4. A method of economic analysis on bridge maintenance is presented. Some economic indexes used in comparison,assessment and optimization of bridge maintenance strategies are given by means of a presented rational profit method. Computing formulae of dynamic maintenance cost are built according to economics. For investment decision in economics,there are mature methods to assess different investment strategies. There are four main optimization goals in bridge maintenance. They are maintenance cost,bridge life,bridge condition state and bridge reliability. They restrain and influence one another and need to be planed as a whole. Through rational profit method,bridge life,bridge condition state and bridge reliability are converted into profit in the paper. This makes it possible to carry out life-cycle economic analysis and optimization for bridge maintenance strategies in a new and more rational method and to transplant more conceptions and methods from economics to bridge maintenance optimization.5. Basic and combining optimization methods of bridge maintenance are presented. Methods of basic optimization of preventive maintenance are presented through establishment of computing formulae of some parameters such as first essential maintenance time,preventive maintenance times and maintenance effect indexes and computing examples of these formulae. Lumping and overlapping combining optimization methods for bridge maintenance are presented. Indexes computing formulae and optimization steps of the two methods are given and their maintenance effect parameters are calculated through examples. Combining optimization methods between an essential maintenance and one or two preventive maintenance are presented. Indexes computing formulae and optimization examples of these methods are given , respectively. Synchronal consideration of essential and preventive maintenance helps those who neglect preventive maintenance traditionally to drop such a traditional idea. At the same time,this lets the built theoretic frame more complete and practical.6. Based on the above achievements,a program,called as BMOP,of life-cycle economic analysis and optimization in bridge maintenance decision is researched and developed. Combined with actual maintenance actions,examples of application of life-cycle economic analysis and optimization in bridge maintenance decision by using this program are given and this shows applicability and signification of the constructed theoretic frame.
【Key words】 bridge; maintenance; multi-objective optimization; life-cycle; economic analysis;