RC桥梁健康状况及承载能力的动力评估试验

Health condition and load carrying capacity evaluation of RC beam based on dynamic testing

根据板梁模型从完整到破坏不同荷载等级作用下室内静、动力试验成果,并结合结构动力学理论,应用非线性回归方法,建立起RC板梁静动刚度比(β)与频率比(α)的回归关系式。提出了名义配筋率(μnom)的概念,并依据板梁在正常使用状态下挠度和裂缝的控制要求以及在承载能力极限状态下强度控制的要求,给出3种控制弯矩的计算公式,同时,把它们表述成名义配筋率的函数形式,用于RC梁健康状况的量化评定。

According to the experimental results which were obtained by dilapidated dynamic test on four model deck beam girder from intact to destroyed, combined with the kinetic theory on bridge structures,the experiential formula between the ratio of static stiffness to dynamic stiffness (β) and the ratio of frequency (α) were founded by nonlinear regression method. All those requirements can be represented as a function of nominal steel percentage (μnom) according to the formula of strength,deflection and crack width limit based on the service ability criterion in the Chinese Design Code.Thus the condition and load carrying capacity can be assessed.