在用桥梁护栏安全性能改进方法研究

为探讨在用桥梁护栏安全性能改进方法,通过实际交通流的观测分析,确定了在用护栏安全性能的检验条件。利用力学分析和三维有限元模拟,确定了兼顾桥梁主体结构安全性和护栏防护性能的在用桥梁护栏安全性能评价方法。设计了具有双层护栏结构的在用桥梁护栏改造方案。结果表明:在用桥梁护栏的典型碰撞检验车辆应选择实际交通流中占有较大比重的车型或需要重点防护的车型,碰撞检验速度取实际交通流的85%位运行速度;在用桥梁护栏安全性能评价应包括防护性能评价和桥梁主体结构安全性评价两部分;内侧梁柱式护栏与外侧组合式护栏结合的改造方案可满足桥梁主体结构安全性要求,防护能力为SS级;在保证防护能力的前提下,可通过景观优化设计使改造后的护栏与环境景观相协调。

Study on Safety Performance Improvement Methods of In-service Highway Bridge Barriers

To explore the improvement methods for safety performance of in-service bridge barriers,testing criteria for safety performance of in-service barriers were determined through observation and analysis of real traffic volume.The evaluation methods for safety performance of in-service bridge barriers considering both safety of major structure of bridge and crash performance of barriers were developed using mechanical analysis and 3D finite element simulation.The reconstruction plan of in-service bridge barriers possessing double barrier structure was designed.The results show that(1)the vehicle type accounting for a great proportion in real traffc volume or the vehicle type requiting major protection should be selected as the typical vehicle for crash testing for in-service bridge barriers;and the 85 percentile of operating speed of real traffic volume should be assumed to be the impact velocity;(2)Safety performance evaluation of in-service bridge barriers should include both crash performance evaluation and safety evaluation of major structure of bridge;(3)the reconstruction plan which combining inner beam-column barrier with external assembled barrier can meet the safety demands of major structure of bridge and the crash level is SS;(4)The reconstructed barrier may harmony with landscape by optimum design on the premise that the crash level can be guaranteed.