下承式刚性系杆拱桥拱座结点受力特点分析

摘要

拱座开裂是拱桥经常出现的病害之一.以某下承式钢管混凝土刚性系杆拱桥为工程背景,探讨了刚性系杆钢管混凝土拱桥拱座微小转动对于此类拱桥拱座处内力的影响,由分析可知:拱座的微小自由转动会造成拱脚、系杆端头弯矩大的改变,即拱座结点受力对微小自由转动敏感.在现实的桥梁中施工初始安装、运营期间的重车过桥,尤其是过桥头伸缩缝时的冲击作用等均有可能带来拱座设计中未能考虑到的微小的自由转动.拱座受力对此微小转动的敏感性,很可能是下承式钢管混凝土刚性系杆拱桥拱座开裂的重要因素之一.%Arch abutments cracking is a common disease of the arch bridge. With a concrete filled steel tube such arch bridge as the engineering background, the influence of small rotation of arch abutments of concrete filled steel tube such arch bridge in internal force of arch abutment is analyzed, with the analysis, small free rotation of the arch abutments will greatly influent the bending moment of arch spring section and the head section of tie bar, also is forces of arch abutment are sensitive of tiny rotation of arch abutments. In actual, initial installation in construction , Heavy vehicle across, especially the impact on the bridge when the vehicle through expansion joint on the head of the bridge will probably bring small free rotation of the arch abutments which unexpected in design programs. So, sensitive of tiny rotation of arch abutments in forces of arch abutments are probably the causes of cracking of arch abutments of concrete filled steel tube such arch bridge.