爆炸荷载下高性能混凝土防护钢筋混凝土矩形墩动态力学响应研究  

Research on Dynamic Mechanical Response of Rectangular Reinforced Concrete Pier with High-Performance Concrete Protection under Explosion

作　　者：朱润田 李源[1] 韩逸涛 蔺渠通 ZHU Runtian;LI Yuan;HAN Yitao;LIN Qutong(School of Highway,Chang′an University,Xi′an 710064,China;Zhuhai Communication Group,Zhuhai 519000,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]珠海交通集团有限公司,广东珠海519000

出　　处：《桥梁建设》2023年第6期111-118,共8页Bridge Construction

基　　金：陕西省自然科学基础研究计划资助项目(2022JQ-415)。

摘　　要：为揭示高性能混凝土(High-Performance Concrete,HPC)防护钢筋混凝土矩形墩在爆炸冲击荷载作用下的动态力学响应及损伤机理,以某跨大堤连续刚构桥钢筋混凝土矩形墩为研究对象进行有限元分析。基于K&C和C&S材料动态本构模型,采用ANSYS/LS-DYNA建立HPC防护前、后的钢筋混凝土矩形墩数值分析模型,对比分析爆炸荷载作用下HPC防护前、后钢筋混凝土矩形墩的动态力学响应,研究防护层厚度(20、30、40 cm)、TNT当量(275、300、325、350 kg)、TNT爆炸距离(10、9、8.5 m)对桥墩抗爆性能的影响。结果表明:HPC防护层能够提升钢筋混凝土矩形墩抗爆性能;采用40 cm厚防护层时,桥墩未出现大面积损伤;TNT当量是影响桥墩损伤特征的重要因素,TNT当量增至350 kg时,桥墩变形、箍筋及主筋应力均显著增加;同等防护条件下,桥墩损伤区域随TNT爆炸距离的减小而显著增加。进行桥墩抗爆防护设计时,应以TNT当量和TNT爆炸距离等条件为基础,设置合理的设防目标。The dynamic mechanical responses and damage mechanism of high-performance concrete(HPC)protected rectangular reinforced concrete piers under explosive loads are investigated.An existing embankment-crossing continuous rigid-frame bridge having such type of piers was used for a case study.Based on the K&C and C&S dynamic material constitutive models,finite element models of the rectangular reinforced concrete pier before and after the addition of HPC protection layer were built up in ANSYS/LS-DYNA to analyze the dynamic mechanical responses of the pier to explosive loads.And the influences of HPC protection layer(with thicknesses of 20,30,and 40 cm,respectively),TNT equivalent(of values of 275,300,325 and 350 kg,respectively),and explosion distance(of 10.9 m and 8.5 m,respectively)on the explosion resistance of the pier were compared.The results demonstrate that adding HPC protection layer can improve the explosion resistance of the rectangular reinforced concrete pier.With a 40 cm-thick HPC protection layer,the pier did not reveal large areas of damage.TNT equivalent is closely associated with the structural damage characteristics of the pier,when the TNT equivalent reaches 350 kg,the deformation of the pier as well as the stresses in the stirrups and main reinforcement are significantly intensified.Under the same level of protection,the pier damage area is inversely related to TNT explosion distance.In the explosion protection design of a pier,the TNT equivalent and TNT explosion distance must be considered so as to set a rational protection target.

关 键 词：刚构桥 钢筋混凝土矩形墩 HPC防护层厚度 TNT当量 TNT爆炸距离 爆炸荷载 动力响应 有限元法 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U443.22[交通运输工程—道路与铁道工程]