旧桥结构内力及变形的非线性影响

采用材料非线性理论,从刚度退化的角度考虑了结构损伤的累积效应,分析了既有钢筋混祆凝土刚架拱桥结构内力及变形,并依托实体工程进行了结构损伤诊断的数值模拟和非线性分析计算.结果表明,考虑结构损伤的累积效应和材料的非线性性质,结构的内力重分布显著,开裂单元范围加大,适用性能和耐久性能降低,这与实桥检测结果吻合.因此,对钢筋混凝土旧桥进行静力评价或拟定加固方案时,应当考虑结构内力及变形的非线性影响.

Nonlinear effects of structure's inner forces and deformation of existing concrete bridge

Based on the nonlinear theory,the accumulation effects of grade stiffness degeneration are considered in structural deterioration.Both inner forces and deformation are analyzed theoretically for existing reinforced concrete arch bridge,the results is used further in the numerical simulation and nonlinear analysis computation of structural damage diagnosis.It is shown that: when the accumulation effects of grade stiffness degeneration and nonlinear characteristic of material are taken into account,the inner forces are redistributed dramatically within structure and the domains with fracture are becoming larger,and the applicability and duration of the structure are lost to some extent,which is consistent with the testing results.So the nonlinearity of inner forces and deformation must be taken into account for evaluating the static characteristics or making the reinforcement plan of the existing concrete bridge.8 tabs,8 refs.