大型换流站阀厅结构地震响应弹塑性分析

Elasto-plastic analysis of seismic responses of valve-hall structure with suspended valves of large-scale converter station

利用有限元方法对带悬挂阀的阀厅结构进行地震响应弹塑性分析,研究不同场地土条件、不同地震动作用对阀厅结构以及悬吊设备地震响应的影响。研究结果表明:阀厅结构在纵向和三向地震作用下存在较明显的扭转效应;三向地震输入时,吊杆产生的拉力约为单向输入的2倍;悬吊设备竖向地震响应大于水平地震响应,大震下悬吊设备竖向加速度约为水平向的4倍,建议阀厅结构地震响应分析时,应考虑三向地震输入对悬吊设备地震响应的增大效应。阀厅结构和悬吊设备的地震响应随着人工波场地土特征周期的增大而增大,且随着地震烈度的增大地震响应的增幅逐渐增大。场地土特征周期分别为0.3 s0、.75 s时,小震作用下钢柱顶部纵向位移峰值差值为51.8%,大震时两者差值增长至119.2%。

Elasto-plastic analysis of seismic responses of valve hall structures are carried out using finite element software,and the effects of soil site conditions and seismic ground motion on the seismic responses of the valve hall structures and suspended equipment are studied.Results show that significant torsional responses of the structure can be found under longitudinal and 3D earthquake actions.Under 3D earthquake actions,the seismic responses of the suspended valves are much stronger than those under 1D earthquake actions.The tensile force of the suspenders is about twice of that under 1D actions.The seismic responses of the suspended valves under vertical earthquake actions are much stronger than those under horizontal earthquake actions.Under strong earthquake actions,the vertical acceleration of the suspended valves is about 4 times that under horizontal earthquake actions.It is recommended that the effects of 3D earthquake actions on the structure should be considered in seismic response analysis of the valve hall structure.The seismic responses of the structure and the suspended equipment can be more significant with the increase of the site soil characteristic period and earthquake intensity.Compared the longitudinal displacements of the steel columns for the site soil characteristic periods being 0.3s and 0.75s,the difference is 51.8% under minor earthquake actions and 119.2% under strong earthquake actions.