Improved Design Limit for Antiram Bollard Systems Subjected to Truck Impact

Antiram bollard systems (ABS) can effectively prevent vehicle bombs from approaching protected areas and thus reduce the damage from blasts and debris. This paper presents an assessment of the current design limits for determining whether the designed ABS can prevent truck penetration successfully according to SD-STD-02.01, Revision A. Four available crash tests and 69 numerical experiments were assembled for the evaluation. Assessment results showed that the current design limits for either residual angle of inclination of bollard ${\alpha }_r$ or residual height of bollard $H_r$ present poor performances. Numerical investigations showed the failed ABS were penetrated by trucks in two failure modes, and Failure Modes I and II can be determined by ${\alpha }_r$ and $H_r$, respectively. On this basis, an improved design limit is proposed in terms of both ${\alpha }_r$ and $H_r$. In addition, an analytical model for predicting ${\alpha }_r$ and $H_r$ is developed. Two plastic-hinge patterns of ABS were considered in this model. Comparisons between the predictions and experimental results from crash tests and numerical simulations indicate that the improved design limit combined with the developed analytical model predicts the performances of all the ABS accurately and can be used for the structural design of ABS.