基于时变可靠度理论的柔性系杆维护决策研究

Study on Maintenance Decision for Flexible Tie Rods Based on Time-Variant Reliability Theory

摘要:

针对我国在役系杆拱桥柔性系杆维护时机决策的量化难题，基于时变可靠度理论构建考虑混凝土抗力衰减的时变抗力模型，并提出改进的PNET（概率网络）法量化多构件失效相关性，解决传统JC法（一次二阶矩法）对体系可靠度的高估问题；同时进一步提出柔性系杆维护阈值判定方法，以量化维护决策时机，为同类桥梁的预防性养护提供了科学依据。

Abstract:

Aiming at the quantification problem of decision-making on the maintenance timing of flexible tie rods for in-service bowstring arch bridges in China, a time-variant resistance model considering the concrete resistance degradation is constructed according to the time-variant reliability theory. And an improved PNET (probabilistic network) method is proposed to quantify the failure correlation of multiple components, resolving the overestimation of system reliability by the traditional JC method (first-order second-moment method). Furthermore, a method for determining the maintenance threshold of flexible tie rods is further proposed to quantify the timing of maintenance decisions, which provides a scientific basis for the preventive maintenance of similar bridges.