中文摘要：

根据弹性中心法，得到由拱脚沉陷引起的两端固支圆拱的附加内力，并通过能量法建立了基于拱脚沉陷的平衡方程和平衡稳定性方程，分析了拱脚沉陷对拱的屈曲性能的影响．研究表明：1）拱脚沉陷将导致拱极限屈曲荷载显著减小；2）不同的深坦度下，拱脚沉陷对拱极限屈曲荷载的影响不同，拱越坦，其影响越明显；3）拱的长细比越小，拱脚沉陷对极限屈曲荷载的影响越明显；4）拱脚沉陷将改变拱屈曲方式的拱型几何参数分界值，拱的对称极值点屈曲的范围将随着拱脚沉陷的增加而扩大．

英文摘要：

Taking circular arch with fixed supports as the research object, the additional internal force due to skewback settlement is calculated by elastic center method. Then, the formula of total potential energy based on skewback settlement is established. According to the energy criterion of structural stability, the balance equation and the equilibrium stability equation are obtained. Next, the effects of skewback settle- ment on buckling performance of circular arch can be worked out by mean of the simultaneous solution of balance equation and equilibrium stability equation. Some conclusions are drawn as follows. 1） skewback settlement will lead to the decrease of buckling load of arch. 2） The effects of skewback settlement on buckling load are changed by opening angle of arch. 3） The effects of skewback settlement on buckling load are more evident with the decrease of slenderness ratio of arch. 4） The dividing values of geometric parameters of arch are altered by skewback settlement.