【作者】 林迟；

【导师】 欧进萍；

【作者基本信息】 哈尔滨工业大学 ， 防灾减灾工程及防护工程， 2010， 博士

【摘要】 结构全寿命设计的特点是在设计阶段就考虑结构建成后养护、检测、维修等后期投资,综合评估建造成本、用户成本和社会成本,力求使总体资源投资最小化。为最终实现可持续结构工程的目标,在结构设计中有必要引入全寿命设计方法。基于全寿命设计与结构“现状设计”方法的差别,其研究范围主要包括设计荷载的持续作用、结构抗力的衰变行为、性能评价的可靠指标、运营管理的系统模型和结构全寿命的经济效益等五个方面。由于环境作用等基础数据的缺乏,极大阻碍了全寿命设计研究工作的开展,同时结构抗力退化规律和性能评价指标的相关研究也不成熟。因此本论文围绕全寿命设计的关键科学问题,对结构所受的各类环境作用、结构性能退化的数值模拟方法和性能评价指标的适用性进行研究,主要工作和研究结果如下:1)疲劳风速是影响大跨桥梁和高层建筑的主要疲劳荷载,现有研究主要集中在极值风速的统计分析上,作为风致疲劳研究基础的疲劳平均风速研究较为匮乏。基于结构全寿命设计对环境作用信息的需求,利用辽宁、深圳和环渤海地区的多年连续测风资料,采用威布尔分布编制相关地区的疲劳风速谱,并对疲劳风速的概率分布特征和威布尔分布的适用性进行分析,在此基础上选取合适的分区指标对我国进行区域划分,同时绘制疲劳风速分区图,为科研人员进行结构全寿命设计研究提供风致疲劳作用及其参数。2)冻结温度是混凝土冻融破坏的重要影响因素,但在冻融作用的统计分析中却往往将其忽略。考虑到冻结温度对冻融破坏强度的影响,利用哈尔滨、北京、呼和浩特、伊宁和郑州等地区1951～2009年的温度数据对该地区冻融作用的概率分布特征进行分析,提出编制冻融作用谱的方法,并在此基础上选取相应的分区指标确立我国的冻融作用区域划分。3)利用哈尔滨、环渤海、深圳和广州等地区的温度数据,对日最高温度、最低温度和温度日较差等温度作用的概率分布特征进行分析,同时建立我国的温度作用分区;针对我国现有桥规未考虑南北气候差异对桥梁温度作用影响的不足,结合气象资料和有限元建模,对大型桥梁空心构件日照升温和寒流降温梯度温度的参数取值进行分析研究,提出其预测公式。4)纤维模型不能直接考虑钢筋粘结滑移的影响,基于Opensees程序和纤维模型,利用零长度单元与Bond_sp01材料模型,对钢筋混凝土结构底柱结点的钢筋粘结滑移现象进行模拟;并通过ANSYS进行精细化建模,研究Bond_sp01材料参数受锈蚀引起的钢筋粘结性能退化的影响;在此基础上计入钢筋粘结性能退化影响,对底柱结点在锈蚀作用下的性能退化规律进行分析,提出可考虑粘结性能退化的纤维模型分析方法。5)“现状设计”方法的性能指标如可靠度指标等,并不能直接反映结构抵抗性能退化的能力,不能满足全寿命设计的要求,为此论文提出以结构/构件寿命作为指标,引入“寿命指标”概念并对其进行定义。通过实验室和实际环境中材料性能退化规律的对应关系,利用所编制的环境作用谱结合实验室获得的材料性能退化规律,对疲劳风作用和冻融作用下结构/构件的服役寿命进行预测,为应用寿命指标提供参考依据。6)从结构层面出发,根据汶川地震中都江堰市2000余栋多龄期建筑的震害调查结果,综合考虑结构类型、设计规范体系和材料性能退化等因素对结构抗震能力退化的影响,对不同龄期建筑的抗震能力进行对比分析,分析可为获得结构整体的性能退化规律提供参考依据。更多还原

【Abstract】 The feature of structural life-cycle design is that it can consider the post-investment resulting from the maintenance, detection, repair, etc. of the constructed structure in the design stage, and minimize the total resource investment through evaluating building cost, customer cost and social cost comprehensively. To achieve the ultimate goal of sustainable structural engineering, it is necessary to introduce the life-cycle method in the structural design. Comparing with the existing design method, the structural life-cycle design mainly includes five research fields, such as the continuing action of design loads, the decay behavior of structural resistance, the reliable index of performance evaluation, the system model of operation and management and the economic benefits of life-cycle design.Since the lack of basic data about the environmental actions, the development of the structural life-cycle theory is severely hindered and meanwhile the relevant researches about the degradation laws of structural resistance and Performance Evaluation are immature, which also limit the application of life-cycle design. Thus around the key scientific issues of structural life-cycle design, we have investigated the attenuation principles of the structure/component function due to the action of various environmental loads and the applicability of the performance evaluation. The main work and research results are as follows:1) The fatigue wind speed is the main fatigue load of large bridge and high-rise building. The current researches primarily focus on the statistic of extreme wind speed, and the fatigue wind speed, which is the base of wind-induced fatigue research, is ignored. To get environmental action spectrums for life-cycle structure design, the continuous wind speed data were employed to compile the fatigue-wind-speed spectrum, which were provided by Changhai wind farm of Liaoning, Luohu weather station etc. of Shenzhen and the stations in Bohai sea. Weibull distribution was adopted herein, and its applicability and the characteristics of the joint distribution of wind Speed and wind Direction are analyzed as well. Based on these results, region division of fatigue wind speed was established to provide wind-induced fatigue action and its parameters for research of life-cycle design.2) Freezing temperature plays an important role in the freezing-thaw damage of the concrete, but is always neglected in counting and analyzing Freeze-thaw action. Considering the effect of the freezing temperature on the freeze-thaw damage, we have investigated the probability distribution of freeze-thaw action of Harbin, Beijing, Hohhot, Yining and Zhengzhou using the temperature data from 1951 to 2009, and a way to compile the freeze-thaw action spectrums was proposed herein. Thus we established freeze-thaw action zones in China through selecting appropriate indicators.3) Utilizing the temperature data of Harbin, Bohai sea, Shenzhen and Guangzhou, we have analyzed the probability distribution of daily extreme temperature (namely, daily maximum and minimum temperature) and diurnal temperature range, and then established temperature action zones in China. In view of the existing regulations did not consider the influence of the climatic differences between south China and north China on the temperature action of the bridges, we have investigated the parameter selection of temperature gradient of sunshine and cold wave on hollow components of large bridge by analyzing meteorological data and generating finite element model, and proposed the prediction formulas.4) Fiber model can not be used to investigate the bond slip of steel directly. Based on the Opensees and fiber model, the bond slip of joint steel in footing was simulated accompany with the zero length element and Bond_sp01 material. By precise modeling with ANSYS, the change law of the parameters of Bond_sp01 under corrosion was studied, and the deterioration of steel bond performance can be considered when analyzing performance degradation of the joint in footing. Thus we proposed a way to consider the descending effects of bonding capacity in fiber-based analysis.5) The function indexes (eg. reliable index) of the current design method, cannot directly reflect the deterioration of structural performance. Therefore we chose the service life of structure/component as index, and the concept of life index was introduced. The service life of structural component under fatigue wind load and freeze-thaw action was predicted, in which the relationship of material performance obtained from laboratory and nature environment, the information of environmental action spectrums and the material performance degradation from experimental results are all involved.6) From the structure level, we have compared the earthquake resistant capability of multi-aged buildings in Dujiangyan City through investigating the seismic damage information of more than 2000 buildings during Wenchuan earthquake in this area. It is helpful in testing and verifying the numerical simulation results through comprehensively considering the effect of various factors such as structure type, design code and aging process on the seismic capacity of buildings. The analysis results can provide reference for investigating the rule of structural behavior deterioration.更多还原