快速移动重载作用下浮桥的波动堆积和移动速度振荡研究  

A study on the wave accumulation and velocity vibration of floating bridges subjected to fast and heavy moving loads

作　　者：江召兵[1] 沈庆[1] 陈徐均[1] 吴广怀[1] 

机构地区：[1]解放军理工大学,江苏南京210007

出　　处：《土木工程学报》2009年第4期93-99,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50779072;10772197)

摘　　要：与一般钢桥或混凝土桥相比,浮桥的抗弯刚度和受弯变形位移波的传播速度都小得多。在快速移动重载作用下,荷载移动速度有可能接近甚至超过浮桥位移波的传播速度,这样就会造成移动荷载前方浮桥位移波的堆积效应。通过求解浮桥运动方程,并利用数值模拟发现:当荷载的移动速度较大时,浮桥的运动呈现明显的波动现象,且有波动的堆积效应和荷载爬坡现象出现。在相应的模型试验中验证了理论和数值模拟中发现的位移波堆积效应。数值模拟和模型试验的结果都表明:荷载越重、速度越大,位移波的堆积越明显。受位移波堆积的影响,快速荷载会发生速度振荡的现象。在快速重载作用下,位移波堆积效应和速度振荡现象也可能出现在民用超长分布式柔性支撑桥(悬索桥、斜拉桥)中,解决这种新的波动问题有较大的学术价值和较广阔的工程应用前景。The stiffness and the propagation velocity of displacement wave for a long floating bridge are much less than those for regular steel or concrete bridges. The effect of the displacement wave accumulation will occur in front of the moving load on a floating bridge subjected to fast and heavy moving load, when the velocity of the load is fastar than that of the propagation of displacement wave. The dynamic equation of the floating bridge is solved by employing the vibration mode superposition method. The wave phenomenon will occur during floating bridge motion and the wave accumulation effect will come up when the velocity of the load is much faster. The wave accumulation effect appeared in the corresponding model test, which validates the theory and the numerical simulation of the dynamics of floating bridges. Both the numerical and the model tests indicated that the wave accumulation effect is more obvious when the load is heavier and the velocity of the load is faster. The load with high velocity will results in velocity vibration because of wave accumulation. The displacement wave accumulation effect and the vibration of loading velocity will occur for civil distribution type flexible super-long bridges （such as suspension bridges and cable-stayed bridges） subjected to fast and heavy loads.

关 键 词：浮桥 快速重载 波动堆积效应 速度振荡 

分 类 号：O313.7[理学—一般力学与力学基础]