考虑气候变化的受碳化腐蚀先张预应力混凝土梁时变可靠性评估  

Time-dependent reliability of pretensioned prestressed concrete bridge girders subject to carbonation-induced corrosion considering climate change

作　　者：彭建新[1] 邵旭东[2] 张建仁[1] 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410004 [2]湖南大学桥梁工程研究所,湖南长沙410082

出　　处：《长沙理工大学学报（自然科学版）》2010年第2期33-42,共10页Journal of Changsha University of Science and Technology:Natural Science

基　　金：交通运输部西部交通建设科技资助项目(200631800019);湖南省交通厅科技资助项目(200614);长沙理工大学人才引进启动项目;长沙理工大学"桥隧学科"创新基金项目

摘　　要：基于改进的碳化深度预测模型,结合IPCC预测大气CO2浓度数据,研究了气候变化(CO2浓度)规律及其对预应力混凝土结构碳化损伤影响,发展了时变可靠度模型计算先张法预应力混凝土结构在多种CO2排放策略作用下、将来100年内的腐蚀开始概率和结构弯曲倒塌概率.研究结果表明,在A1FI排放策略下,腐蚀开始概率比其在最好CO2排放策略下高了460%;在A1FI排放策略下,结构失效概率比其在最好CO2排放策略下高了10%.在高腐蚀状态下,结构失效概率是低腐蚀状态下的2倍,且结构在高腐蚀状态下条件年度失效概率后期增长较快.在最高CO2排放策略下,结构条件年度失效概率比其在最好CO2排放策略下高了30%.当混凝土保护层设计厚度增至40 mm时,碳化腐蚀对混凝土结构的影响很小.Based on the corrected carbonation depth prediction model,the present study describes how climate change predicted increases in CO2 levels will affect carbonation-induced damage to pretensioned prestressed concrete bridge girders using information on climate change provided by the IPCC.The time-dependent structural reliability analysis will predict the probability of corrosion initiation and probability of failure of a typical pretensioned prestressed concrete bridge girder over the next 100 years considering several IPCC future atmospheric CO2 emission scenarios.For the worst case of emission scenario the probability of corrosion initiation is 460% higher than the best mitigation scenario.For the worst case of emission scenario the probability of failure is 10% higher than that observed in the best mitigation scenario.For the higher deterioration,the probability of failure is 100% higher than the lower deterioration and initially the annual probability of failure reduces with time but then increases at later ages due to the effects of deterioration.For the worst emission scenario the conditional annual probability of failure is 30% higher than that observed for the best mitigation.When the design cover is increased to 40 mm,the influence of carbonation is small.

关 键 词：桥梁工程 气候变化 碳化 腐蚀 时变可靠度 

分 类 号：U444[建筑科学—桥梁与隧道工程]