强震作用下循环水泵房结构地震动力破坏机理分析

Study on Earthquake Damage Mechanism of Pump House Structure under Strong Earthquake

无限域地基精准的数值模拟是解决结构动力学问题的重要方法之一。为研究地震动力持时过程中泵房结构在边界效应下的动力破坏机理及损伤发展规律,以某循环水泵房为例,应用黏弹性边界、动力无限元边界分别进行抗震时域分析,引入混凝土塑性损伤本构,验证无限元边界效应对波动能量的吸收效果。结果表明,位移响应规律中,无限元边界对波的远域能量逸散效果与黏弹性边界分析结果二者接近,并且无限元边界施加形式更为简单,建模效率高;强震响应下蜗壳环向、肘形流道弯管段底部及扩散段两侧容易出现损伤破坏现象,以上这些部位在泵房结构抗震设计中应加以着重考虑。

Accurate numerical simulation of infinite ground is one of the important methods to solve structural dynamics problems.In order to study the dynamic failure mechanism and damage development law of pump house structure under boundary effect in the process of earthquake dynamic duration,taking a circulating water pump house as an example,the viscous-spring(V-S)boundary and dynamic infinite element(IEM)boundary are applied to conduct seismic time-domain analysis,and by introducing concrete plastic damage(CDP)constitutive model,the absorption effect of infinite element boundary effect on wave energy is verified.The results show that,(a)the far-field energy dissipation effect of IEM boundary is close to that of V-S boundary analysis in displacement response law,and the IEM boundary is more simple and the modeling efficiency is high;and(b)under strong earthquake response,the damage and failure phenomena are easy to occur at the bottom of the volute and elbow-shaped duct and the two sides of the diffusion section of the elbow channel,and the above parts should be emphatically taken into account in the anti-seismic design of pump house structure.