【作者】 姚晓飞；

【导师】 徐岳； 王春生；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2009， 博士

【摘要】 论文以国内外混凝土桥梁承载能力和技术状况评定资料收集分析为基础，以可持续发展为指导思想，以其他行业可靠性评定标准为借鉴，依托西部交通建设科技项目“混凝土梁式桥梁损伤评估与安全可靠性评价技术研究”(200531822316)，对占我国公路桥梁绝大多数的混凝土梁式桥就损伤评估及可靠性评定进行了系统的研究。1、以《公路桥涵养护规范》(JTG H11-2004)中关于四、五类桥梁的病害为对象，在广泛调研和资料收集分析的基础上开展损伤定义与分类工作。依据损伤出现频率与重要性等级，提出典型损伤混凝土梁式桥按体系损伤、构件损伤和材料损伤三个层次进行评定的原则。2、基于构件和材料层次损伤评估研究成果，对比分析损伤机理和适用条件，提出了《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG D62-2004)抗弯承载力修正计算公式、抗剪承载力修正计算公式以及综合考虑抗剪强度影响因素的抗剪承载力评定公式。3、针对混凝土梁式桥主要横向连接形式，分别按铰结、翼缘刚接和横隔梁刚性连接损伤对T桥梁桥承载能力的影响进行了模型试验和有限元分析，研究了不同损伤工况对T梁桥荷载横向分配的影响及横向连接状态退化情况。通过试验结果分析，提出了混凝土梁式桥活载横向分布调整系数(状态)原则和计算公式。4、针对横向连接损伤对混凝土梁式桥荷载效应的影响，引入活载横向分布调整系数对已有荷载效应模型进行了修正。针对材料和构件损伤对混凝土梁式桥抗力的影响，基于材料和构件层次典型损伤的修正计算公式，在结构既有以及时变抗力评估的概率模型基础上，通过误差传递公式获得抗力统计参数，对抗力进行修正，构成了考虑混凝土梁式桥典型损伤的安全性分析方法。5、依据校准法原理，将《公路桥涵养护规范》(JTG H11-2004)中不同类别承载力下降率转化为修改分项系数，分别计算了轴心受压、轴心受拉、受弯、大偏心受压、受剪构件在各种情况下的可靠指标，根据破坏类型对校准结果进行分析，提出了基于可靠度的公路混凝土梁式桥安全性评定等级。6、基于不能继续承载的裂缝和位移的相关国内外规范和研究成果分析，通过类比提出了混凝土梁式桥不能继续承载的裂缝和位移评定等级界限。在体系损伤试验分析基础上，提出了铰接、翼缘刚接和横隔梁刚性连接构造评定等级。7、根据混凝土梁式桥结构特点和已有研究结果，建立了基于可靠度的考虑横向连接损伤的混凝土梁式桥安全性评定等级，采用层次分析法建立了单主梁和多主梁混凝土梁式桥评定模型和评定方法。然后进行了实桥应用及分析。8、基于相关规范适用性评定标准和方法总结分析，从最大裂缝宽度和挠度方面确定了混凝土梁式桥适用性评定等级，采用层次分析法建立了单主梁和多主梁混凝土梁式桥适用性评定模型以及评定方法。在安全性和适用性评定的基础上，采用层次分析法建立了混凝土梁式桥可靠性综合评定流程、评定等级。更多还原

【Abstract】 On the basis of analysis of bearing capacity and safety state grade evaluation of existing concrete beam bridges at home and abroad, this dissertation draws lessons from the reliability appraiser standards of related fields, and studies the damage evaluation and reliability assessment of existing concrete beam bridges which accounts for the overwhelming majority of highway bridges in China. In detail, the following aspects are investigated:1. Considering diseases about the fourth and fifth degree bridges defined by Code for Maintenance of Highway Bridges and Culvers (JTG H11-2004), damage definition and classification was undertaken on the basis of wide range survey and data analysis. According to the frequency and importance of bridge damages, the author presented the assessment principles for typical concrete beam bridges by the three levels of system injury, component and material damage.2. Based on the studies about damage assessment on the level of materials and components, the author made a comparative analysis on the damage mechanism and applicable conditions, and put forward the amended formulas for calculating the flexural and shears capacity, which were defined in the Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts (JTG D62-2004). The assessment formula for shear capacity was established as well, and in which various impact factors of shear strength was considered comprehensively.3. Directed against the main forms of transverse connection in concrete beam bridges, model test and finite element analysis were carried out to find the impact laws of damage on concrete T-beam bridges, in which the three ways of hinged joint, flange rigid connection and cross slab rigid connection were considered. Transverse distribution and degenerate state of transverse connection were studied under various damage conditions. Based on the analysis of test and simulation results, the rule of live load adjustment coefficient (state) of T-beam bridge was put forward, as well as the calculation formula.4. In view of the influence of the damaged transverse connections to load effect, the load effect model was amended by live load adjustment coefficient. Based on the probability assessment model of existed and time-dependent, the resistance was amended with the help of the statistical parameters of resistance get by error propagation formula, in which amendment formulas on the materials and component-level about typical damage was used and the influence of material and component damages on resistance was considered. Then, safety analysis method was constituted considered the typical damage of concrete beam bridge. 5. By amending the reduction rate of loading capacity used in Code for Maintenance of Highway Bridges and Culvers (JTG H11-2004), a new reliable index is presented in the same safety standard to reflect the relation between load and resistance. According to the basic principal of calibration method, the recommended gradation index was computed under various factors such as different load combinations, vehicle operating status and different failure modes. With these calculated numerical values, the calculated reliability indexes standard for the estimation of safety degree of in-service concrete girder bridge members was ultimately obtained.6. Based on the related standards and results on crack and displacement that cannot continue to loading at home and abroad, the evaluation grade of the concrete beam bridge is proposed by analogy. In the foundation of experiment results, the evaluation ranks of the hinge, the flange rigid connection and diaphragm rigid connection was presented.7. According to the structural characteristics and research results of concrete beam bridges, safe assessment grades was established based on reliability and transverse connection damage. And assessment model and method was founded by means of Analytic Hierarchy Process. And the assess system find its way to apply in a real bridge.8. Considering the summarization of applicability assessment standard of other codes, applicability assessment grade of concrete beam bridges was founded in the view of max-crack and flexibility. And assessment model and method was put forward by means of Analytic Hierarchy Process; and reliability synthetical assessment flow and grades was established too.更多还原