考虑流固耦合效应的弧形钢闸门地震动力响应研究

Seismic dynamic responses of spillway radial steel gates considering fluid-solid coupling effects

在地震高发的中国西南地区,地震激励对弧形钢闸门的安全持续稳定运行影响较大,有必要对弧形闸门在地震作用下的动力响应及安全性进行研究。以某工程表孔弧形钢闸门为例,通过建立考虑水体和结构耦合作用的三维数值模型,研究了弧形钢闸门地震动力响应,然后利用重力坝-库水流固耦合模型验证了计算方法的准确性和有效性,最后对弧形钢闸门进行动力时程响应分析,计算了弧门地震动水压力,并与规范方法进行对比。结果表明:本文提出的考虑流固耦合效应的动力响应分析方法适用于闸门地震动力响应计算;流固耦合效应对弧形钢闸门地震动力响应影响较大,考虑流固耦合效应的闸门动力响应计算结果比规范明显增大,两者最大比值达到2倍以上。闸门结构动位移响应峰值在闸门面板顶部中心,动应力响应峰值发生在下主横梁跨中;流固耦合的动力计算表明该闸门结构刚度满足规范要求,强度不能满足,上、下主横梁处为结构动力响应薄弱环节;对高水头采用规范法计算的地震动水压力偏大,对低水头动水压力计算结果偏小。考虑流固耦合的闸门结构动力响应分析研究能反映其真实力学特征,对于地震高发区弧形钢闸门的结构设计和安全评价具有参考意义。

In the southwest area of China where earthquakes are frequent,the seismic excitation has a great impact on the safe,continuous and stable operation of radial steel gates.It is necessary to study the dynamic response of radial steel gates to the earthquakes and the effect of earthquakes on the safety of the gates.Here,a three-dimensional numerical model considering the coupling effect of water body and structure was constructed,and the seismic dynamic response of the gate was studied.According to the calculation results of the gravity dam-reservoir fluid-solid coupling model,this method was proved to be accurate and effective.Furthermore,the dynamic time history response of the gate was analyzed,and the hydrodynamic pressure of the gate was calculated and then compared with the standard method in the specification.The results show that the dynamic response analysis method proposed in this paper is suitable for the calculation of the seismic dynamic response of radial steel gates,the fluid-solid coupling effect has a great influence on the seismic response of radial steel gates.Considering the fluid-structure coupling effect,the calculation result of the dynamic response of the gate is significantly larger than that of the standard method in the specification,and the maximum value of the ratio is more than two times larger.The dynamic displacement response peak of the gate structure is at the center of the gate top panel,and the dynamic stress response peak occurs in the middle of the lower main beam.The dynamic calculation of fluid-solid coupling shows that the rigidity of the gate structure meets the specification requirements,but the strength does not.The structural dynamic response of the upper and lower main beams are weak,the seismic water pressure calculated by the standard high-head method is rather large,whereas the calculation result of the low-head hydrodynamic pressure of the surface hole is too small.The dynamic response analysis of the gate structure considering the fluid-solid coupling can reflect the true mechanical characteristics of the gate,and has guiding value for the structural design and safety evaluation of radial gates in the earthquake-prone areas.