SS级装配式混凝土护栏钢筋错位拼插连接设计及碰撞性能研究

Research on Design and Crash Performance of SS-Class Prefabricated Concrete Guardrails with Staggered Steel Bar Lap-splice Connections

摘要:

为提升桥梁装配式混凝土护栏的施工效率与连接可靠性，以桂林市外环高速公路工程为背景，提出一种采用U型钢筋错位拼插竖向连接与纵向剪力铰组合的护栏连接方案。介绍了钢筋错位拼插连接和纵向剪力铰的设计原理并进行了承载力验算。基于LS-DYNA建立了护栏-车辆耦合有限元模型，开展了大型客车、大型货车和小型客车的碰撞仿真分析。结果表明，护栏端部和中部的横向承载力均达到《公路护栏安全性能评价标准》（JTG B05-01—2013）规定的最高桥梁护栏设计防护等级规定，3种不同车型碰撞下的护栏横向动态变形、车辆外倾当量值和乘员加速度同样满足相关要求。与现有护栏连接方案相比，所提方案的综合单价较现浇方案节约了12.8%，并在安装容差、施工速度和综合造价方面具有明显优势。

Abstract:

To enhance the construction efficiency and connection reliability of prefabricated concrete guardrails for bridges, based on the Guilin Outer Ring Expressway Project, a guardrail connection scheme is proposed, which combines a staggered U-shaped steel bar lap-spliced vertical connection with a longitudinal shear hinge. The design principles of the staggered steel bar lap-spliced connection and the longitudinal shear hinge are introduced, and their load-bearing capacities are verified. A guardrail-vehicle coupled finite element model is established using LS-DYNA, and crash simulations are performed for a large bus, a large truck and a small passenger car. The results indicate that the transverse load-bearing capacities at both the end and middle sections of the guardrail meet the highest design protection level for bridge guardrails specified in the Highway Guardrail Safety Performance Evaluation Standards (JTG B05-01 - 2013). Furthermore, the transverse dynamic deflection of the guardrail, the vehicle rollover equivalent value, and the occupant acceleration under collisions with the three vehicle types also satisfy the corresponding requirements. Compared with existing guardrail connection methods, the comprehensive unit price of the proposed scheme is 12.8% lower than that of the cast-in-place scheme, which has obvious advantages in installation tolerance, construction speed and comprehensive cost.