节点文献
在役钢筋混凝土桥梁的耐久性评估与剩余寿命预测
The Durability Assessment and Remaining Life Prediction of Reinforced Concrete Bridge in Service
【作者】 谢立安；
【导师】 张谢东；
【作者基本信息】 武汉理工大学 ， 公路桥梁与渡河工程， 2009， 硕士
【摘要】 在役钢筋混凝土桥梁的特点是结构抗力随时间不断衰减,其耐久性评估与剩余寿命预测是桥梁工程领域内广为关注的问题之一。本文在总结前人研究成果的基础上,主要开展了以下几个方面的研究:首先,根据混凝土碳化、混凝土强度的经时变化以及钢筋锈蚀等因素对在役钢筋混凝土桥梁结构抗力衰减的影响机理,在基于混凝土的截面宽度、有效高度和受压区高度在结构服役期间变化很小可以忽略的假定上,给出在役钢筋混凝土桥梁的结构抗力衰减模型。其次,利用平稳二项随机过程和荷载效应与荷载之间呈线性关系的理论知识推导出在役钢筋混凝土桥梁的恒载效应与车辆荷载效应在设计基准期内和目标评估期内的最大值分布函数以及车辆荷载效应随车辆荷载交通量增长的目标评估期内的最大值分布函数,同时给出在役钢筋混凝土桥梁时变可靠度分析时车辆荷载效应的最终计算结果。再次,给出在役钢筋混凝土桥梁时变可靠度分析的数学模型以及用中心点法计算在役钢筋混凝土桥梁时变可靠指标的计算公式。依据在役钢筋混凝土桥梁的结构重要程度和使用情况等因素给出目标评估期内结构的目标可靠度或目标可靠指标,并以承载力寿命准则为基础,运用结构时变可靠度理论对在役钢筋混凝土桥梁的技术使用寿命与技术剩余使用寿命进行预测,同时还给出技术使用寿命与技术剩余使用寿命的预测步骤。然后,结合桥梁全寿命周期内运营成本的灰色性和跳跃性特征,采用改进的不等时距的GM(1,1)模型和改进的不等时距的灾变预测模型来预测在役钢筋混凝土桥梁每年的运营成本,并以年平均成本最小为目标,鉴于开口向上的二次抛物线在其对称轴处取得最小值的特性,给出在役钢筋混凝土桥梁的经济使用寿命与经济剩余使用寿命的预测方法。最后,结合海南省三亚市三亚大桥新加宽桥,给出资料不详的在役钢筋混凝土桥梁的耐久性评估与剩余寿命预测的方法。
【Abstract】 Reinforced concrete bridge in service is characterized by its structure resistance decay over time, and the durability assessment and remaining life prediction of which is one of the widely concerned problems within the field of bridge engineering. Following studies have mainly been done after summarizing the results of previous research:First of all, grounded on the mechanism that concrete carbonation, concrete strength changing over time, the corrosion of steel bars and other factors have effects on structure resistance decay over time of reinforced concrete bridge in service, based on the assumption that the changes of concrete cross-section width, effective height and the height of compression zone in the structure service period are so small that can be ignored, the structural resistance decay model of reinforced concrete bridge in service is put forward.Secondly, founded on the theory knowledge of the stationary binomial random process and the linear relationship between load effect and load, the maximum distribution functions of dead load effect and vehicle load effect of reinforced concrete bridge in service within the design reference period and the objective assessment period are deduced, at the same time, the maximum distribution function of vehicle load effect with the vehicle traffic increase within the objective assessment period is also proved. The final result of the vehicle load effect used to analyze the time-dependent reliability of reinforced concrete bridge in service is also given.Thirdly, the mathematical model used to analyze the time-dependent reliability of reinforced concrete bridge in service is put forward, and the formulas used to calculate the time-dependent reliability index of reinforced concrete bridge in service by center method is also given. Grounded on the structure importance degree, service condition and other factors of the reinforced concrete bridge in service, the target reliability or target reliability index of the structure is put forward. Founded on the carrying capacity life criteria, the structure time-dependent reliability theory is utilized to predict the technical life and technical remaining life of reinforced concrete bridge in service. Simultaneously, the prediction steps of the technical life and technical remaining life is also given.Then, combined with the gray and jumping characteristics of the operating cost within the bridge whole life cycle, the annual operating cost of reinforced concrete bridge in service can be determined by the improved different time-distance GM(1,1) model with the improved different time-distance disaster prediction model. Given the characteristic that quadratic parabola which opens the mouth upwardly obtains the minimum value in its symmetry axis, the method predicing the economic life and economic remaining life of reinforced concrete bridge in service which aims at the minimum average annual cost is given.Finally, combined with the new widened bridge of Sanya Bridge located in Sanya City Hainan Province, the method of the durability assessment and remaining life prediction of reinforced concrete bridge in service with not detailed information is put forward.