后张预应力钢束有效预应力分布模式判别与模拟方法

Distribution mode determination and simulation method of effective prestress for post-prestressing tendon

在大、中跨径混凝土桥梁预应力状况检测及评价的实施过程中,为了获知预应力束筋当前预应力有效值及其分布状态,提出了有效预应力沿程分布的统一模拟方法。基于预应力损失理论,建立了具有普遍意义的拟摩阻损失函数简化解析算法。以单束可控测点处的应力测值为已知条件,结合钢束沿程有效预应力分布状况的隶属模式判别,完成了名义损失参数识别,实现了复杂几何型式钢束实际有效预应力沿程分布规律的统一模拟。模拟结果表明:有效预应力相对误差阈值为5%,满足工程精度要求,因此,统一模拟方法可行。

In order to know the effective value and longitudinal distribution state of effective prestress in inspection and evaluation process on the present condition of prestressing tendon for middle-span and long-span concrete bridges, an unified simulation method of the distribution was put forward. Based on prestress loss theory, a simplified analytic algorithm of virtual frictional loss function was set up in a universal way. By the means of the obtained stress datum of steel tendon at control point, the subordinated mode of effective prestress distribution along longitudinal direction was determined. As regards the effective prestress of steel tendon with complicated geometry pattern, its distribution regularity was simulated after the recognition of nominal coefficients for prestress loss. Simulation result shows that the relative error of effective prestress threshold is 5%, so the simulation method is feasible. 1 tab, 10 figs, 16 refs.