动水压下减震连续梁桥随机优化及减震性能研究

地震作用下,跨海桥梁桥墩和周围水体的动力相互作用将对桥梁结构的动力响应产生较大影响。建立了考虑动水压力的2自由度连续梁桥简化分析模型,推导了其组合刚度和附加质量;提出了以墩顶位移方差最小为目标的黏滞阻尼器参数随机优化的Lyapunov方法。在此基础上,通过对设置黏滞阻尼器的某跨海连续梁桥简化模型进行了阻尼器参数优化,研究了动水压力和地震耦合作用下连续梁桥的减震性能。研究结果表明:动水压力增大了桥梁的地震反应,对桥梁的动力响应特性有较大影响。采用黏滞阻尼器可有效减小跨海连续梁桥的地震反应,改善桥梁结构抗震安全性能。

Stochastic optimization and aseismic performance of continuous girder bridge with viscous dampers under hydrodynamic pressure

Under earthquake,dynamic interaction between bridge pier and surrounding water can have a great impact on dynamic response of a bridge structure.Here,a simplified analysis model for a 2-DOF continuous beam bridge considering hydrodynamic pressure was established,and its combined stiffness and added mass were derived.A Lyapunov method for stochastic optimization of parameters of viscous dampers with the minimum displacement variance at pier top taken as the objective was proposed.Then,damper parameters of a simplified model of a sea-crossing continuous girder bridge with viscous dampers were optimized to study the aseismic performance of the continuous girder bridge under the interaction of hydrodynamic pressure and earthquake.The results showed that the seismic response of the bridge is increased by hydrodynamic pressure,the latter has a greater impact on the bridge’s dynamic response characteristics;using viscous dampers can effectively reduce seismic response of a sea-crossing continuous girder bridge to improve its aseismic safe performance.