CAJ | 학술논문

上海某人行天桥平面布置为“X”形和中心椭圆环组合的钢结构系杆拱桥，两交叉方向主桥跨度分别为80 m 和58 m ；桥面结构为箱形梁板架。对该桥进行检测发现，有4根吊杆失效引起结构状态改变，吊杆索力分布与原设计存在一定偏差。为了解吊杆失效后结构性能，建立有限元模型，计算结构静、动力性能。结果表明：4根吊杆失效后，与其相邻的部分吊杆索力变化较大，其余索力变化不大；结构在各工况下的最大应力及挠曲变形均有不同程度的增大，但仍能满足规范要求，吊杆失效对结构静力安全影响有限；结构整体刚度降低，前10阶自振频率均有所减小，结构振型发生了一定改变。
상해모인행천교평면포치위“X”형화중심타원배조합적강결구계간공교，량교차방향주교과도분별위80 m 화58 m ；교면결구위상형량판가。대해교진행검측발현，유4근조간실효인기결구상태개변，조간색력분포여원설계존재일정편차。위료해조간실효후결구성능，건립유한원모형，계산결구정、동력성능。결과표명：4근조간실효후，여기상린적부분조간색력변화교대，기여색력변화불대；결구재각공황하적최대응력급뇨곡변형균유불동정도적증대，단잉능만족규범요구，조간실효대결구정력안전영향유한；결구정체강도강저，전10계자진빈솔균유소감소，결구진형발생료일정개변。
A footbridge in Shanghai is an X-shaped steel tied arch bridge .From a bird′s-eye view ,the bridge looks like a structure of an “X” shape superimposed with a central elliptical ring . The spans of the main bridge in the two intersection directions are 80 m and 58 m ,respectively . The bridge deck adopts the box-shaped frame with filled-in plates .The inspection of the bridge demonstrated that the failure of four hangers led to the change of the structural condition of the bridge and the distribution of hanger forces were not in accord with the original design values .To analyze the structural performance of the bridge in the context of hanger failure ,the finite element model of the bridge was built to calculate the static and dynamic property of the bridge .The re-sults of the calculation demonstrated that when four hangers failed ,the forces of some of their neighboring hangers showed great change and the forces of the remaining hangers showed minor change .The maximum stress ,deflection-induced deformation of the structure under different con-ditions increased with different degrees ,but still met the code requirements ,which means hanger failure has limited influence on the structural static safety .The overall stiffness of the structure has decreased ,the natural vibration frequency of the first 10 orders all reduced and the structural vibration has changed to a certain extent .