K4级可自动升降式防撞柱系统性能的数值分析

摘要

To study the performance of the K4-rating auto-lifting anti-ram bollard system ( AABS) , the vehicle impact process is simulated by using the numerical method.The impact simulation is car-ried out by using a modified truck model, and the simulation results are compared with the real vehi-cle test results to verify the validity of the proposed model.Based on the numerical model, the effects of the boundary conditions on the performance of the AABS are investigated.By using 32 or-thogonal numerical experiments, the significance order of the parameters is obtained.The results show that when the compression modulus is small, the maximum rotate angle of the steel anti-ram bollard decreases with the increase of the compression modulus.But when the compression modulus is greater than 10 MPa, the maximum rotate angle increases with the increase of the compression modulus.Among all the parameters, the gap between the substructure and the outer sleeve is the most important factor affecting the performance of the AABS.In practical engineering, the compres-sion modulus of the surrounding soil is suggested to be 8.5 to 12.0 MPa and the gap between the substructure and the outer sleeve is advised to be as small as possible.%为研究K4级可自动升降式防撞柱系统的性能，采用数值方法对该系统进行了车辆撞击全过程模拟．采用修正后车辆模型进行撞击模拟，并将模拟结果与实车试验数据进行对比，以验证模型的有效性．基于此模型研究了不同边界条件对防撞柱系统性能的影响，并通过32组正交数值试验，得到防撞柱各影响参数的显著性排序．研究结果表明，当土体压缩模量较小时，钢管防撞柱最大转角随土体压缩模量的增大而减小；当土体压缩模量大于10 MPa时，最大转角随土体压缩模量的增大而增大．在所有影响因素中，外套筒与底部构造的间隙对防撞柱系统性能的影响最大．建议在实际工程中将基础周围土体的压缩模量控制为8.5～12．0 MPa，并尽可能减小防撞柱底部构造与外套筒的间隙．