锈蚀RC梁加固后时变可靠性分析

TIME-DEPENDENT RELIABILITY ANALYSIS OF REINFORCED CORRODED RC BEAMS

为分析锈蚀钢筋混凝土梁的耐久性,考虑钢筋与锚栓的锈蚀以及加固钢板的滞后效应影响,建立了锈蚀RC梁加固后的可靠性模型。基于服役40年的锈蚀损伤钢筋混凝土梁,采用Monte-Carlo法,讨论了分配荷载效应、汽车荷载等级、加固钢板厚度以及钢筋保护层厚度的对结构可靠性的影响。分析结果表明:汽车荷载等级对可靠性影响有较大的差异性;加固钢板厚度增大可以显著提高结构的可靠性指标,但钢板过厚结构易发生脆性破坏且钢板无法得到充分利用;保护层厚度对结构可靠性指标的提高并不明显。

To analyze the durability of corroded reinforced concrete beams, both the effect of the corrosion of steel and anchor bolts and the lag effect are considered. A reliability model of the corroded reinforced concrete beams is established. Based on the reinforced concrete beam for 40 years of service, the effects of distributed load effect, vehicle load level, steel plate reinforcement thickness and protective layer thickness are discussed by using Monte-Carlo method. The analysis results show that the influence of vehicle load level on reliability is quite different. The thickness of the steel plate can improve the reliability index significantly, but structures with excessive thickness of the steel plate is prone to brittle failure and the steel plate can not be fully utilized. The thickness of the protective layer can not significantly improve the reliability of the beam.