石拱桥拱脚开裂过程中的内力分析

Internal Force Analysis of Stone Arch Bridge in Course of Crackin g at Arch Foot

采用空间梁单元对实际的石拱桥拱脚开裂现象进行了有限元模拟分析.随着开裂深度的变化,主拱圈中的内力进行重新分配,得出了不同开裂深度时主拱圈中的内力分布规律,对实际的各种受力状态和开裂过程中的内力进行了较精确的数值描述.当拱脚裂纹扩展时,拱脚截面上的弯矩明显减小,轴力明显增大,而其它截面上的弯矩增大,轴力也增大.截面上的内力值与开裂深度成非线性关系.

The internal force of stone arch bridge in the course of cracking at arch foot was computed using the spatial finite beam element method. With the variation of depth of the crack, the internal forces in the main arch circle are redistributed. The internal forces in the m ain arch circle are described accurately by numerical value. With the increase o f depth of the crack, the moment is decreased and the axial force is increased at arch foot section, but the moments are increased and the axial forces are increa sed too at the other sections. The relations of internal forces and depth of cra ck at arch foot is nonlinear. 