Methodology of Reliability Analysis and Evaluation of Earthquake Resistant Performance of Deteriorating Concrete Bridges

(1)针对氯离子引起的混凝土劣化和碳化，提出了一种基于目测、电化学试验和劣化预测的混凝土劣化状态评定方法，并将其应用于实际劣化钢筋混凝土结构，验证了该方法的适用性。该方法考虑了钢筋混凝土梁的劣化状态(潜伏期、发展期、加速期、劣化期)和承载能力等性能指标对周围环境的影响，以及这两个指标随时间变化的性能。(2)考虑混凝土强度分布和冷缝缺陷，进行了一系列钢筋混凝土梁的抗剪强度试验，提出了考虑这些因素的抗剪强度估算公式。(3)对包括钢筋混凝土单墩的桥梁结构体系进行了地震反应分析，评估了桥墩、支座、支座等构件之间的损伤相关性。对混凝土结构的性能要求进行了分类，建立了劣化与性能劣化的关系模型。在此基础上，提出了混凝土结构性能验证的基本概念和寿命假设。(5)提出了桥梁结构体系在强震作用下多种损伤状态的评估方法。通过对碱-硅酸反应劣化的钢筋混凝土梁进行了一系列的抗剪强度试验，评价了在反复荷载作用下钢筋混凝土梁的抗剪强度退化。(7)采用离散单元法对影响钢筋混凝土独柱式桥墩破坏的多种因素进行了研究。

(1) On chloride induced deterioration and carbonation of concrete, a condition rating method based on visual inspection, electro-chemical experiments and prediction of deterioration, was developed and applied to an actual deteriorating RC structure and demonstrated its suitability. This method considers the state of deterioration (Latent period, Development period, Acceleration period, Deterioration period) and the performance such as load carrying capacity influence on surrounding, and, performance over time for these two items.(2) A series of shear strength testing of RC beams were conducted considering the distribution of concrete strength and the cold joint defect and a estimation equation of shear strength considering these factors was proposed.(3) The earthquake response analyses of bridge structural system including RC single piers were performed to evaluate the damage correlation among members such as piers, bearings, and, superstructures.(4) The performance requirements for concrete structures were classified and the relationship between deterioration and performance degradation was modeled. Then, a basic concept of performance verification and scenario for lifetime of concrete structures were proposed.(5) An evaluation method for multiple damage states of bridge structural system due to strong earthquake was proposed. The probability of multiple damage states of structural elements were evaluated by Marcov-chain.(6) A series of shear strength testing of RC beams with deterioration due to Alkali-Silica Reaction were carried out to evaluate degradation in shear strength under reversed cyclic loading.(7) A study on a number of factors such as ground motion components, structural defects, etc., influencing the failure of RC single column bridge piers was carried out by the Discrete Element Method (DEM).