中文摘要：

通过建立龙头石水电站厂房三维有限元动力分析模型，研究了厂房固有振动特性并进行了共振复核，同时研究了机墩在各种动荷载作用下的振幅和应力。利用动力法计算厂房在水力激励荷载作用下的振动反应，并根据国内外有关振动规程，对振动加以评价。研究结果表明，厂房上部框架结构自振频率与机组转频相差不大，可能发生共振，根据计算结果提出了修改设计的建议。厂房整体结构刚度较大，振动反应基本在允许范围内，可以满足设计要求；共振区振动反应较为突出，应重点关注。振动应力较小，不应成为控制参量。

英文摘要：

The natural vibration frequency and the possibility of resonance of the powerhouse in Longtoushi Hydropower Station were analyzed by using 3-D FEM. The vibration amplitude and stress of pier structure under dynamic load were calculated. The harmonic and transient analysis methods were proposed to study the dynamic response of the powerhouse structure under the hydraulic excitation force in the spiral case and draft tube. The numerical results were evaluated according to the related rules and regulations both in China and abroad. The result shows that the vibration response of the power house structure is in the limitation of the rules and regulations. But the frame structure on the upper part of the powerhouse has a similar frequency with the rotating frequency of the generator set, the possibility of resonance is high. A proposal for mitigation is suggested.