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公路上正常行驶的车辆一旦操纵失控,安装在路侧的护栏就显得极为重要,可避免车辆直接冲出道路发生致命危险.波形梁护栏是最常见的一种被动防护装置,可有效抵御车辆施加的碰撞荷载.依据常规的设计思路,这种护栏可以利用波形梁板、防阻块和立柱的变形来吸收汽车碰撞所产生的能量.但与实际情况不同的是,在这一过程中忽略了地基土体对碰撞过程可能产生的影响.本文通过分别建立不考虑和考虑地基约束作用的碰撞计算模型来研究土体的贡献.在模拟过程中,分别观测货车的运行轨迹、护栏的变形和土体的变形.此外,也分析了不同部件对碰撞能量的吸收比率.与立柱接触区毗邻的土体因受冲击荷载影响,可能发生剪切失效.整个护栏系统中超过10%的系统能量实际上是由土体吸收的,常用的简化固定基模型跟实际情况有一定的出入.
Once the normal driving on a highway is out of control, the guardrail installed on the roadside becomes extremely important to avoid the fatal danger of the vehicle going straight out of the road.Wave beam guardrail is the most common kind of passive guard that can effectively resist the vehicle applied Of the collision load.According to the conventional design ideas, this fence can take advantage of the deformation of the wave beam plate, anti-block and column to absorb the energy generated by car collision.But with the actual situation is ignored in this process The impact of foundation soil on the collision process.This paper studies the contribution of soil by establishing the collision calculation model without considering and considering the constraint of the foundation respectively.During the simulation process, observe the running track of the truck, the deformation of the guardrail and soil In addition, the absorption ratio of different components to the collision energy is also analyzed.The soil adjacent to the column contact area may be subject to shearing failure due to the impact load.Moreover, more than 10% of the system energy in the whole guardrail system actually Is absorbed by the soil, commonly used to simplify the fixed-base model with the actual situation have some discrepancies.