预应力混凝土箱梁爆炸损伤评估及公式拟合

Explosion Damage Assessment and Formula Fitting of Prestressed Concrete Box Girder

摘要:

对预应力混凝土箱梁进行爆炸损伤评估研究。首先，对矩形梁进行爆炸数值分析，结合现场试验结果验证了爆炸数值模型的准确性、可靠性。其次，基于箱梁剩余承载力，建立了箱梁爆后损伤评估准则。通过对预应力混凝土箱梁在不同爆炸工况下的爆后剩余承载力计算，建立箱梁各损伤程度下P?I（超压?冲量）曲线。研究发现，混凝土强度对箱梁超压和冲量临界值影响较大，钢筋屈服强度对超压和冲量临界值影响较小。随着结构损伤等级的增大，各参数对箱梁P?I曲线的影响幅度各不相同。最后，对不同混凝土强度箱梁中各损伤等级P?I曲线进行公式拟合，并对拟合参数β进行分析。

关键词:预应力混凝土箱梁;爆炸损伤;评估准则;参数化分析;公式拟合

Abstract:

In this paper， the explosion damage assessment of prestressed concrete box girder is studied. First， the numerical analysis model of rectangular beam explosion is conducted， and the accuracy and reliability of the explosion numerical model is verified by the field test results. Then， based on the residual bearing capacity of the structure， the damage assessment criterion of box girder at explosion load is established. By analyzing the residual bearing capacity of box girders at explosion load， the P-I （pressure–impulse） curves of various damage degrees of box girders are determined. The results show that the concrete strength has a greater influence on the critical value of overpressure and impulse， while the yield strength of reinforcement has less influence. With the increase of damage grade， the influence amplitude of each parameter on P-I curve of box girder is different. Finally， the formula fitting of P-I curves of all damage grades of box girder with different concrete strength is performed， and the fitting parameter β is analyzed.

Key words:prestressed concrete box girder;explosion injury;evaluative criteria;parametric analysis;formula fitting