运营桥梁防撞护栏承载能力验算评估存在的问题及新的计算方法初探

Check and Assessment Problems and New-Calculation-Method Research of Bearing Capacity of the Anti-Collision Guardrail for the Old Bridge

我国公路交通安全设施设计系列规范有关公路桥梁防撞护栏的防撞性能验算方式中,针对护栏本身的强度采用基于能量法的塑性变形屈服线理论,而对护栏与梁板悬臂的连接强度,则引入了能力保护构件的设计理论。将该计算理论评估运营桥梁性能,特别是修建年代较早的桥梁护栏体系的承载能力评价,适用性并不强,难以对结构体系的承载能力进行准确评估。在深入分析现行规范计算理论的基础上,针对旧桥评估分析中存在的问题,改进了相关评估思路,提出了“削弱截面法”的计算评估方法,使其对旧桥防撞护栏的承载能力评估更加准确。

In the series of specifications for the design of highway traffic safety facilities in terms of performance check of anti-collision guardrail in China,the plastic deformation yield line theory based on the energy method is adopted for the strength of the guardrail itself,and the design theory of capacity protection component is introduced for the connection strength between the guardrail and the cantilever of beam plate.When this theory is used to evaluate the performance of bridge in operation,especially for the bearing capacity evaluation of guardrail system of old bridges.,it is difficult to evaluate the bearing capacity of the structure system accurately because the applicability of the calculation theory is not strong.Based on the in-depth analysis of the current code calculation theory,aiming at the problems existing in the evaluation and analysis of old bridges,this paper improves the relevant evaluation ideas,and puts forward the calculation and evaluation method of"weakening section method",so as to make the evaluation of the bearing capacity of anti-collision guardrails of old bridges more accurate.