爆炸冲击荷载下装配式钢筋混凝土工字梁桥损伤机理研究  

Research on Damage Mechanism of Segmental Reinforced Concrete I-Girder Bridge Under Explosive Loads

作　　者：李源[1] 蔺渠通 殷怡萍 王尧翔 董勤龙 LI Yuan;LIN Qutong;YIN Yiping;WANG Yaoxiang;DONG Qinlong(School of Highway,Chang′an University,Xi′an 710064,China)

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《桥梁建设》2025年第1期72-79,共8页Bridge Construction

基　　金：陕西省自然科学基础研究计划资助项目(2024JC-YBMS-321)。

摘　　要：为提升装配式工字梁桥的抗爆防护性能,制作3片跨径150 cm的钢筋混凝土工字试验梁,进行接触爆炸试验,得到试验梁在50、100、200 g爆炸当量下的损伤表征,并与数值模型分析结果对比验证。以中山西环高速公路桥为背景,建立装配式工字梁桥数值分析模型,根据美国联邦紧急措施署(FEMA)标准,分析等效227 kg和454 kg爆炸当量下的装配式工字梁桥受爆力学性能和动力响应。结果表明:工字试验梁在50、100、200 g爆炸当量的接触爆炸试验中表现出局部冲剪破坏模式,顶板破坏特征为由腹板向自由边45°方向的混凝土脱落,并出现纵向裂缝,腹板破坏为显著的冲剪破坏,其冲剪高度随爆炸当量的增加而增大;在爆炸荷载下,装配式工字梁桥结构损伤特征表现为局部冲剪破坏、整体弯曲变形和高频振动;454 kg爆炸当量下,工字梁桥主梁动能峰值显著高于227 kg爆炸当量,到达峰值时间更早,且残余变形明显,导致承载能力下降;装配式工字梁桥设计时应优先增强结构的局部抗冲剪性能,同时加强横向联系及主梁截面高度。To improve the blast protection performance of segmental I-girder bridges,three reinforced concrete I-girder specimens with a span length of 150 cm each were prepared for the contact explosion tests.The damage characteristics of specimens under explosive equivalents of 50,100,and 200 g were obtained and compared with numerical analysis results.Taking the Zhongshan West Ring Expressway Bridge as a reference,a numerical analysis model of the segmental I-girder bridge was established.According to the standards of the American Federal Emergency Management Agency(FEMA),the mechanical performance and dynamic responses of the segmental I-girder bridge under equivalent explosive loads of 227 kg and 454 kg were analyzed.The results show that in the contact explosion tests with explosive equivalents of 50,100,and 200 g,the I-girder specimens exhibited localized shear failure.The top plate failure was characterized by the detachment of concrete from the web in a 45°direction towards the free edge,with the occurrence of longitudinal cracks.The web failure was marked by significant shear failure,with the height of shear failure increasing with the explosive equivalent.Under explosive loading,the structural damage characteristics of the segmental I-girder bridge were manifested as localized shear failure,overall bending deformation,and high-frequency vibrations.Under the 454 kg explosive equivalent,the kinetic energy peak of the superstructure of the I-girder bridge was significantly higher than that under the 227 kg explosive equivalent,reaching the peak earlier,with noticeable residual deformation,and leading to a decrease in load-bearing capacity.The design of segmental I-girder bridges should prioritize enhancing the local shear resistance of the structure,while strengthening transverse connections and increasing the height of the cross-section of the main girder.

关 键 词：装配式梁桥 钢筋混凝土工字梁 爆炸当量 冲剪破坏 动力响应 模型试验 爆炸试验 数值分析 

分 类 号：U448.218[建筑科学—桥梁与隧道工程] U448.212[交通运输工程—道路与铁道工程]