高速公路隧道入口护栏侧倾控制研究

Study on Roll Control of Guardrail at Entrance of Expressway Tunnel

为了保证车辆在隧道入口处的行车安全,针对隧道入口处车辆碰撞护栏产生侧倾而撞击隧道壁的问题,通过现有有限元仿真结果与实车足尺碰撞试验结果在驶出角度、车辆变形以及行驶轨迹等方面进行对比,校核了不同车型的有限元仿真的计算参数。采用理论分析、有限元仿真技术等方法,分析了护栏坡面、护栏高度、护栏刚度及强度指标对车辆侧倾的影响关系。结果表明:直壁式坡面的防侧倾能力优于F型坡面和单坡面;护栏高度越高,防侧倾的效果越好,随着护栏高度的增加,侧倾角度减小的幅度逐渐降低,即1.5 m的护栏可兼顾经济性和功能性,为护栏结构最优的高度值;护栏的刚度与其防侧倾功能之间并不存在线性关系,即并非护栏刚度越大越好,但较小的护栏刚度会影响整体结构的强度,造成零件的破坏;通过仿真分析,大刚度立柱和高吸能横梁结构对于控制侧倾效果尤为显著。结合隧道入口实际条件,确定了满足隧道入口车辆侧倾指标阈值为45 cm,并得到一种SB级防侧倾型隧道入口护栏结构。通过有限元仿真分析验证,满足隧道入口护栏侧倾控制小于45 cm的要求,提高了隧道入口护栏的侧倾防护能力,可有效提升高速公路隧道入口处的交通安全运营水平。

In order to ensure the driving safety of vehicles at tunnel entrance, to cope with the problem that the vehicles at tunnel entrance collide with the guardrail at the entrance of the tunnel and rolls and hits the tunnel wall, through the comparison between the existing finite element simulation result and the full-scale collision test result of real vehicles in terms of driving angle, vehicle deformation and driving track, the calculation parameters of finite element simulation of different vehicle types are checked. The influences of guardrail slope, guardrail height, guardrail stiffness and strength on vehicle roll are analyzed by means of theoretical analysis and finite element simulation technology. The result shows that(1) The anti roll ability of straight wall slope is better than that of F-shaped slope and single slope.(2) The higher the guardrail height, the better the anti roll effect. With the increase of guardrail height, the decrease of roll angle gradually decreases, i.e., 1.5 m guardrail can give consideration to both economy and functionality, which is the optimal height value of guardrail structure.(3) There is no linear relationship between the stiffness and anti roll function of guardrail, i.e., it is not that the greater the stiffness of the guardrail, the better, but small guardrail stiffness will affect the strength of the overall structure and cause damage to the parts. The simulation analysis shows that the large rigidity column and high energy absorption beam structure have particularly significant effect on controlling roll. Combining with the actual condition of the tunnel entrance, it is determined that the threshold value of the vehicle roll indicator at tunnel entrance is 45 cm, and a SB grade anti roll guardrail structure for tunnel entrance is obtained. Through the finite element simulation analysis and verification, it meets the requirements that the roll control of the tunnel entrance guardrail less than 45 cm, which improved the roll protection ability of the tunnel entrance guardrail, and can effectively improve the traffic safety operation level at the entrance of the expressway tunnel.