车辆与风联合作用下大跨度桥梁的疲劳损伤时变可靠度评估

随着经济发展和交通量的增长，沿海和峡谷地区大跨度桥梁经受大风和随机车流的作用，导致大桥疲劳失效风险增高。而大跨度桥梁又是国家经济发展的交通命脉，为了评估大跨度桥梁的疲劳损伤，预测大桥剩余寿命，实现大跨度桥梁安全运营和科学管理，本项目拟开展车辆和风荷载联合作用下大跨度桥梁疲劳损伤时变可靠度评估研究。主要包括以下几个方面的工作：.（1）进一步拓展和完善风-车-桥系统气动特性测试的实验技术方法，准确识别车辆、桥梁气动力参数；.（2）开展车辆荷载的随机特性研究，实现双向多车道随机车流模拟；.（3）开展车辆的等效车轮荷载研究，建立一种综合的风-车-桥耦合振动分析模型；.（4）开展疲劳损伤模型研究，基于可靠度理论，建立大跨度桥梁疲劳损伤时变可靠度评估框架，研究大桥疲劳损伤累积过程，预测剩余寿命，编制适用程序。

With the economic development and traffic volume growth, long-span bridges in the coastal and canyon areas are subjected to high winds and stochastic traffic flow, resulting in high risk of fatigue failure of bridges. Long-span bridges are the transport lifelines of the country's economic development. In order to evaluate the fatigue damage of long-span bridges, predict the bridge remaining life and make sure safe operation and scientific management for current long-span bridges, this project plans to carry out time-dependent fatigue reliability assessment long-span bridges under the combined effects of vehicles and wind loads. The main work includes the following aspects:.(1) Further expand and improve the experimental techniques for testing of aerodynamic characteristics of wind-vehicle-bridge system, and accurately measure aerodynamic force coefficients of the vehicles and bridges..(2) Carry out the random characteristics of the traffic load and realize random traffic flow simulation of two-way multi-lane..(3) Carry out the equivalent vehicle wheel loads studies and establish an integrated wind-vehicle-bridge coupled vibration analysis model..(4) Carry out fatigue damage model, establish a time-dependent fatigue reliability assessment framework for long-span bridges based on reliability theory, study the bridge fatigue damage accumulation process to predict the remaining life, and write applicable software programs.