摘要
在复杂环境与荷载作用下,桥梁的抗力会随着时间的推移而退化,可靠性降低,导致桥梁提前破坏,这关系到桥梁耐久性、适用性和安全性问题。准确评估桥梁的安全状况,为桥梁管养部门在维护、维修和修复等方面及时提出合理建议措施,意义重大。文章首先建立了Gamma随机过程抗力退化模型与泊松(Poisson)随机过程荷载模型。在此基础上,基于抗力和荷载效应相互独立的基本假定,使用条件概率公式,严格得到了结构失效概率计算表达式,并提出了一种改进的时变可靠度Monte Carlo计算方法,最后用Matlab语言编制了相应计算程序。作为一个应用算例,利用文章所建立的双随机过程模型和可靠度计算方法,分析了某现钢筋混凝土T型梁桥服役20 a的抗力可靠度衰减规律。与传统的时变可靠度计算方法相比,本文方法不但可行、有效,而且效率高。另外,以腐蚀机制下的桥梁抗力退化模型为例,预测得到桥梁在后30 a时的失效概率以及可靠指标。
Under complex environment and load, the deterioration of bridges resistance overtime will reduce the reliability and finally an unexpected failure occur suddenly impacting the durability, adaptability and safety of bridges. Therefore, it is of great significance to evaluate accurately the safety state of bridge and put forward timely reasonable suggestions and measures in maintenance, repair and resilience for bridge management and maintenance department. A Gamma stochastic process model for resistance degradation and a Poisson stochastic process model for live load were firstly established. Based on the two models and basic assumption that resistance and load effect are independent of each other, an expression for calculating structural failure probability was thus derived by using conditional probability formula, and an improved method to compute time-dependent probability calculation with Monte Carlo sampling was proposed. Finally, the Matlab language was used to compile the corresponding numerical program. As a benchmark example, the proposed method was used to investigate the attenuation law of reliability in resistance of a 20 years reinforced concrete T-beam bridge. Compared to the conventional method for calculating time-dependent probability, the present method not only is feasible and effective, but also has higher efficiency. In addition, taking the bridge resistance degradation model under corrosion mechanism as an example, The failure probability and reliability index of the bridge in the next 30 years are predicted.
作者
陈梦成
张明阳
方苇
杨超
李骐
温清清
谈勇
彭爱红
游勇利
Chen Mengcheng;Zhang Mingyang;Fang Wei;Yang Chao;Li Qi;Wen Qingqing;Tan Yong;Peng Aihong;You Yongli(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China;State Key Laboratory of Performance Monitoring and Guarantee of Rail Transportation Infrastructure,East China Jiaotong University,Nanchang 330013,China;School of Architectural Engineering,Jiangxi Communications Vocational and Technical College,Nanchang 330013,China;Expreswory Managoment Office of Jiangxi Provincial Department of Transportation,Nanchang 330036,China;Jiangxi Communications Engineering Group Construction Co.,Ltd,Nanchang 330006,China;Jiangxi Highway Research and Design Institute,Nanchang 330002,China;Jiangxi Jiahe Engineering Consulting and Supervision Co.,Ltd,Nanchang 330009,China)
出处
《华东交通大学学报》
2022年第4期16-23,共8页
Journal of East China Jiaotong University
基金
国家自然基金项目(51878275)
江西省交通运输厅科技项目(2019Q0024)
江西省交通运输厅科技项目(2021H0009)
江西省教育厅科技项目(GJJ90299)。
关键词
桥梁工程
退化模型
荷载模型
随机过程
时变可靠度
bridge engineering
degradation model
load model
random process
time varying reliability
