独塔混凝土斜拉桥性能退化后拉索体系安全概率特性研究

Research on Safety Probability Characteristics of Cable System after Performance Degradation of Single-pylon Concrete Cable-stayed Bridges

摘要:

随着服役时间增长，独塔混凝土斜拉桥面临性能退化问题，准确评估其结构可靠性对保障桥梁安全运营至关重要。为此，从确定性和概率性综合角度出发，针对独塔混凝土斜拉桥性能退化后的可靠性展开了深入分析。首先，运用确定性方法建立退化桥梁的力学分析模型，精确计算结构在既定荷载工况下的承载能力、内力分布等关键指标，以获取结构性能的基本状态；其次，考虑材料性能退化和不同位置处等不确定性因素，采用概率方法量化斜拉索安全系数，构建全面、科学的可靠性评估体系。研究成果能够准确反映性能退化后独塔混凝土斜拉桥的真实可靠性水平，为独塔混凝土斜拉桥的风险评估、维修加固决策提供可靠依据，对延长桥梁使用寿命、保障交通基础设施安全具有重要的理论意义与实践价值。

Abstract:

With the increase of service time, single-pylon concrete cable-stayed bridges face the problem of performance degradation. Accurately evaluating their structural reliability is crucial to ensure the safe operation of the bridge. Therefore, the in-depth analysis is conducted on the reliability of single-pylon concrete cable-stayed bridges after performance degradation from the perspectives of both certainty and probability. Firstly, a deterministic method is used to establish a mechanical analysis model for degraded bridges, accurately calculating key indicators such as the bearing capacity and internal force distribution of the structure under established load conditions, and obtaining the basic state of structural performance. At the same time, considering uncertain factors such as material performance degradation and different locations, the probability methods are adopted to quantify the safety factor of stayed cables, and a comprehensive and scientific reliability assessment system is built. The research results can more accurately reflect the true reliability level of single-pylon concrete cable-stayed bridges after performance degradation, providing reliable basis for risk assessment, maintenance and reinforcement decision-making of single-pylon concrete cable-stayed bridges, which has important theoretical significance and practical value for extending the service life of bridges and ensuring the safety of transportation infrastructure.