预应力混凝土箱梁爆炸荷载模型试验及有限元分析  

Experimental and finite element analysis of the explosion load model for prestressed concrete box girders

作　　者：孙启鑫 刘超[2] SUN Qixin;LIU Chao(School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]浙江理工大学建筑工程学院,杭州310018 [2]同济大学土木工程学院,上海200092

出　　处：《振动与冲击》2024年第14期37-46,共10页Journal of Vibration and Shock

摘　　要：目前针对箱梁爆炸荷载以及冲击波传播规律的研究较少,以目前混凝土桥中应用较为广泛的预应力混凝土箱梁桥为依托工程,以1∶5缩尺比例设计箱梁爆炸荷载试验。试验表明,箱梁顶板超压沿箱梁纵向呈非线性下降梯度分布特点,超压沿箱梁横向近似于梯形荷载分布,随着比例距离的减小,结构超压增大。其次,基于箱梁爆炸荷载试验,建立箱梁三维爆炸数值分析模型,通过将数值分析结果和试验数据进行对比,验证数值模拟的准确性。基于数值分析,揭示爆炸冲击波与箱梁的相互作用机理,明确箱梁冲击波的传播规律。对不同爆炸工况箱梁各部位超压分布规律研究显示:当爆心位于箱梁顶板上方时,顶板迎爆面超压较大;当爆心位于翼缘板下方时,在翼缘和腹板处产生较大超压,其余部位超压较小。而当爆心位于箱梁底板下方时,翼缘、腹板和底板均受到较大的冲击波超压,结构全截面受爆炸影响较大。最后,基于试验和数值分析结果,对不同工况下箱梁顶板、腹板和底板的超压峰值进行方程拟合,建立不同爆炸工况下箱梁关键部位荷载模型。At present,there are few researches on the blast pressure load and shock wave propagation in box girders.Based on the engineering background of a prestressed concrete box girder bridge which is widely used in concrete bridge design at present,the explosion load test of the prestressed box girder was carried out with a scale of 1∶5.The experimental results show that the overpressure on the top plate of the box girder exhibits a non-linear descending gradient distribution along the longitudinal direction of the box girder,and the overpressure is distributed along the transverse direction of the box girder as an approximate trapezoidal load.As the proportional distance decreases,the overpressure increases gradually.Based on the explosion load test of the box girder,a three-dimensional numerical analysis model of box girder explosion was established.The accuracy of the numerical simulation was verified by comparing the numerical analysis results with the experimental data.Based on the numerical results,the interaction mechanism between the blast wave and box girder was revealed,and the propagation law of shock wave was clarified.Further researches on the distribution of overpressure on different parts of the box girder under different explosion conditions show that when the detonation core is located above the top of the box girder,the overpressure on the top surface of the box girder is larger;when the detonation core is located below the flange plate,the overpressure on the flange and web of the box girder is larger,and the overpressure on other parts is smaller.The blast center is located under the bottom plate of the box girder,and the flange,web and bottom plate of the box girder are subjected to large shock wave overpressure,and the full section of the structure is greatly affected by the explosion.Finally,based on the experimental and numerical analysis results,the equations of the peak overpressure on the top plate,web plate and bottom plate of the box girder under different working conditions were fitted,a

关 键 词：预应力混凝土箱梁 爆炸试验 数值模拟 机理分析 荷载模型 

分 类 号：U442.59[建筑科学—桥梁与隧道工程]