利用振动法测量预应力体外索的索力

Measurement of cable tension of external prestressed cable by using vibration method

为了能够利用振动法测量316国道洪塘大桥预应力体外索的索力,本文根据理想弦的振动方程以及梁的横向振动方程,建立起有灌浆预应力体外索索力的计算模型,该计算模型中含有两个权重系数λ1、λ2。利用该桥体外预应力索的模型实验数据,通过最小二乘法拟合出系数λ1、λ2并得到体外索索力的计算公式。误差分析表明该体外索索力计算公式误差小,可以用于洪塘大桥体外索索力计算以及该桥体外索长期健康监测。

In order to use the vibration method to measure the cable tension of the external prestressed cable of Hongtan Bridge on 316 national road, according to the simple taut string theory and the transverse vibration theory of beam, this paper establishes the calculation model of cable tension of the grouting external prestressed cable. This calculation model has two indeterminate coefficients λ1 andλ2 . Using the model testing data of Hongtan Bridge external prestressed cable, by the least square technique, the coefficientAlandA2 are found out. Error analysis indicates that the error of the formula to estimate cable tension of the grouting external prestressed is small. And this formula can be used to calculate the cable tension of Hongtan Bridge and its long - term health monitoring.