Abstract: Based on the approximate vibration functions,which meet with the boundary conditions and symmetry of deflection vibration of arch,the simplified equations for calculating the lowest symmetrical vibration natunal frequency are derived by enengy method.When f/l≥0.2,the frequency results from the simplified method are nearly the same as from finite element method.

Key words: arch, symmetrical deflection vibration, vibration function and frequency

摘要： 忽略拱的轴向变形,选取满足边界条件和对称性的近似振型函数,运用能量法导出单孔圆弧拱对称挠曲振动基频的实用计算公式.与有限元结果比较,矢跨比f/l≥0.2时吻合较好.

关键词: 圆弧拱, 对称挠曲, 振型与基频