考虑多因素作用下的RC梁抗力时空退化模型

发布时间：2018-05-01 06:41

本文选题：锈蚀梁 + 抗力退化　；参考：《哈尔滨工业大学学报》2017年09期

【摘要】：为研究钢筋混凝土结构锈蚀后的力学性能和抗力退化规律,基于RC梁加速锈蚀试验结果,首先综合考虑均匀锈蚀和点蚀同时发生的影响,对钢筋截面面积的时变模型进行分析,其次探讨裂缝宽度与氯离子扩散系数及RC梁抗力的关系,随后考虑受拉主筋锈蚀不均衡的影响,对结构抗力计算模型进行讨论,最后基于材料性能和结构尺寸的空间变异性,建立RC梁抗力时空退化模型,并对桥梁服役100 a后的抗力进行预测.研究发现:当考虑各参数的空间变异性时,不考虑裂缝影响得到的抗力值比考虑裂缝影响得到的抗力值高了9.91%;考虑各参数空间变异性时的抗力值比不考虑时下降了14.68%;适当的选取波动系数和单元尺寸对考虑结构各参数的空间变异性十分重要;潮汐区和浪溅区环境下结构的剩余抗力分别为初始抗力的43.23%和36.45%,较海岸线大气区环境下的抗力值分别下降了6.73%和21.35%,因此在结构服役期间,应尽量做好防腐措施,减少氯离子侵蚀对结构耐久性的破坏.
[Abstract]:In order to study the mechanical properties and the law of resistance degradation after corrosion of reinforced concrete structures, based on the results of accelerated corrosion test of RC beams, the time-varying model of steel section area is analyzed by considering the effect of uniform corrosion and pitting, and the relationship between the crack width and the chloride diffusion coefficient and the resistance of the RC beam is discussed. After considering the influence of the uneven corrosion of the main reinforcement, the calculation model of the structural resistance is discussed. Finally, based on the spatial variability of material properties and structural dimensions, the time and space degradation model of the RC beam resistance is established and the resistance of the bridge after 100 a is predicted. The resistance value obtained by the response is 9.91% higher than that obtained by considering the effect of the crack. The resistance value of the parameters when considering the spatial variability of the parameters is 14.68% lower than that without consideration; the proper selection of the fluctuation coefficient and unit size is very important to consider the spatial variability of the structural parameters; the residual resistance of the structure under the tidal zone and the wave splash zone is divided. The resistance values of the initial resistance are 43.23% and 36.45%, and the resistance values of the coastline atmosphere are decreased by 6.73% and 21.35% respectively. Therefore, during the structural service, the anticorrosion measures should be done as far as possible to reduce the damage of the chloride ion erosion to the durability of the structure.

【作者单位】：桥梁工程安全控制省部共建教育部重点实验室(长沙理工大学);
【基金】：国家重点基础研究发展计划(2015CB057701) 国家自然科学基金面上项目(51178060,51378081) 湖南省教育厅优秀青年项目(15B015) 长沙理工大学交通基础设施安全风险管理行业重点实验室开放基金(16BCX08)
【分类号】：TU375.1

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