桥梁撞击问题研究的新方法

为了更准确地研究桥梁撞击问题,介绍了当前常用的计算最大撞击力的经验公式,指出它们的局限性。从动量和能量双重角度来分析和研究桥梁撞击问题,提出了一种研究桥梁撞击问题的新方法。认为桥梁在受到撞击后做阻尼简谐振动,提出了如等效振幅、等效弹性系数等概念。用高采样率高精度的RTK-GPS技术采集撞击瞬间及撞击后短时间段内的桥梁振动数据,利用动量守恒和能量守恒定理,得出桥梁所能承受的最大撞击,并通过现场试验对新方法的有效性进行了验证。试验结果表明,提出的方法具有一定的实用性,并得出了一些有益的结论。

A New Research Method for Bridge Impact

In order to investigate bridge impact more accurately,a new research method for bridge impact was proposed.Several empirical formulas for maximal impact force calculation commonly used in current period were introduced,and their limitations were pointed out.It was suggested that to investigate bridge impact from both aspects:momentum and energy.The impacted bridge was considered to do simple harmonic oscillation with damping after impact.Some new concepts,such as equivalent amplitude,equivalent coefficient of elasticity,etc.were put forward.RTK-GPS which with high sample rate and precision was used to collect the oscillation data of bridges during and after the impact instant.According to both principles of conversation of momentum and energy,strict mechanical formulas were deduced,and the maximal impact the bridge can endure was elicited.In order to testify the effectiveness of the new method,an in situ experiment was conducted.Experiment result indicates that the proposed method has some certain practicability,and some useful conclusions were drawn.