For large curvature arch, the neutral axis does not pass through the centroidal line of the cross-section, so the moment of inertia is not consistent with the second moment of area.

• 大曲率拱中,截面形心轴与中性轴不重合,其截面抗弯惯性矩与不考虑曲率影响的截面面积二阶矩有一定的差别;当截面尺寸相对拱弧长来说较大时,此时拱为深拱,剪切变形的影响不能忽略。