高速公路跨铁路桥梁护栏安全性能提升研究

Study on Improving Safety Performance of the Cross-rail Highway Bridge Guardrail

为提升某跨铁路高速公路桥梁护栏的安全防护功能,运用调查分析、有限元计算与实车足尺碰撞试验综合技术手段,了解跨铁路高速公路桥梁护栏应具有高防护等级与减小车辆碰撞护栏时侧倾量的特殊防护需求,而原有护栏经过分析不满足该防护需求。针对这种情况提出了升级改造方案,并对方案的安全可靠性进行了验证。结果表明:护栏经1.5t小客车100km/h、18t大型客车80km/h、33t整体大货车60km/h以20°夹角碰撞检测,乘员碰撞后加速度最大为70.6m/s^(2),乘员碰撞速度最大为8.4m/s,大型客车与整体大货车碰撞护栏后最大动态外倾当量值分别为0.38m和0.41m,护栏达到了SS级高防护等级和车辆碰撞后低侧倾量的功能要求;护栏基座预埋螺栓经计算机仿真校核,其受力满足强度要求;结合现场设置条件及规范要求进行设计的护栏端部过渡结构,经计算机仿真分析验证,其具有安全可靠性。研究成果提高了跨铁路桥梁路段运营安全水平。

In order to improve the safety protection function of the guardrail on a cross-rail highway bridge,the comprehensive technical means of investigation,finite element calculation,and full-scale impact test with the real vehicle are used to understand that the bridge barrier should have high protection level and the special protection demand of low roll after the vehicle collision,but the original guardrail of this cross-rail bridge does not meet the protection needs after analysis.In view of this situation,the upgrading scheme is proposed,and the security and reliability of the scheme are verified.The results show that the crash tests are carried out using 1.5 tcar,18 tbus and 33 trigid truck with the impact angle 20°respectively with the impact velocity of 100 km/h,80 km/h and 60 km/h;the maximum occupant ride down acceleration and the maximum occupant impact velocity are 70.6 m/s^(2) and 8.4 m/s separately;the normalized maximum dynamic vehicle incline-out distance of 18 tbus and 33 trigid truck is 0.38 mand0.41 mrespectively;the guardrail reaches the functional requirements of SS protection level and low roll amount after vehicles collision;the embedded bolt of the guardrail base meets the strength requirement checked by computer simulation;the transition structure of the guardrail end is safe and reliable,which is designed according to the site setting conditions and specification requirements.The research achievements improve the safety level of the cross-rail highway bridge.