两自由度体系地震碰撞影响因素及防撞研究

The Research of Influencing Factors of Pounding for Double DOFs Subjected to Earthquake and Measure of Preventing Pounding

地震作用下连续梁桥结构会遭受很大的破坏,碰撞的发生极大地改变了桥梁的动力响应,对桥梁结构整体或局部都产生极大危害。本文基于连续梁桥两个自由度体系的简化力学模型,建立了体系的运动方程,通过方程的标准化处理,确定影响桥梁碰撞响应的主要因素,如质量比,桥梁相邻联周期比(刚度比),地震动特征周期比和体系延性系数比。采用四阶Runge-Kutta法,通过MATLAB来实现整个求解过程。研究了各个因素对两自由度体系碰撞响应的影响,得出其碰撞影响区域。最后,选取粘滞阻尼器对该体系进行了防撞研究,防撞效果明显。

Bridge structure may suffer great damage subjected to earthquake,which will hav e significant influence on the seismic responses of bridges and cause great dama ge to the overall and part of bridge.The simplified mechanical model of the con tinuous bridge and the structure equation of motion are addressed.By the calibr ation of motion equation,the main factors that influenc bridge pounding respons e are determined used,i.e.,the ratio of mass λ,the ratio of period betwe en adjacent bridges K1/K2（ration of stiffness K1/K2）,the ratio of characteristic period of earthquake ground motions K1/K2 and ductility factor of structrues μ.Then the classical fou rth-order Runge-Kutta method for solving first-order differential equation is w ell suited for computational solution.The system of equation is implemented in MATLAB.In double degree of freedom system,the influencing factors are investi gated and how each factor influence the dynamic response of the structure can be summarized.Finally,a measure to prevent the pounding or decrease the seismic pounding responses is addressed,the dynamic response of bridge structure can be efficiently decreased by utilizing suitable viscous damper through research.