预应力CFRP板加固混凝土梁桥的可靠度分析

Analysis on Reliability of RC Girder Bridge Strengthened with Pre-stressed CFRP Plates

基于Weibull分布类型推导了受尺寸和应力分布影响的CFRP板抗力概率模型,根据实桥加固方案建立了预应力碳纤维加固T梁的抗力概率模型,获得了抗力均值、标准差,并认为其抗力不拒绝对数正态分布。在此基础上,考虑公路II级荷载标准,计算了预应力碳纤维加固主梁的抗弯承载力可靠指标,从结构可靠度理论角度评估了加固效果,并进行了可靠度参数敏感性分析,分析了设计失效模式下主梁采用预应力碳纤维加固后的可靠度主要影响因素。研究成果是加固桥梁结构力学评价的有益补充,可为碳纤维加固桥梁的设计规程编制提供理论基础。

The probabilistic model of resistance for the carbon fiber reinforced plastic（ CFRP） plate influenced by size and stress distribution is derived based on the Weibull distribution types. The probabilistic model of resistance for T-beam reinforced by prestressed CFRP plate is established according to real bridge reinforcement scheme. The mean value and standard deviation of resistance are obtained. It is considered that the distribution of resistance does not refuse the lognormal distribution. The reliability indicators of flexural resistance for the main beam reinforced by prestressed CFRP plate are calculated according to the highway level Ⅱ load criterion. The reinforcement effect is evaluated from the perspective of structural reliability theory,and the sensitivity analysis of reliability parameters is carried out. The main influencing factors on reliability of the main beam reinforced by CFRP plate under the design failure mode are analyzed. The result is a supplement for assessing structural mechanics of reinforced bridges. It can be a theoretical basis for working out the design specification of bridges reinforced by CFRP plates.