锚索预应力声测技术研究及工程应用

鉴于混凝土在低应力受载条件下声速与声幅随应力的变化不明显的特点，利用由小波处理获取的对应力敏感的加权波谱参数，作为锚索预应力测试的中间指标，通过锚索预张拉过程中混凝土锚墩所受荷载与加权波谱参数相关关系的标定曲线，由锚索预应力声波监测数据反算预应力荷载。工程应用结果表明，这种技术在当荷载变化超过50kN时，声波波谱参数变化较明显，可以反映预应力损失的变化过程，并与荷载传感器监测结果能较好地吻合。

ULTRASONIC TESTING ON THE LOAD MONITORING OF PRE-STRESSED CABLE AND ITS APPLICATION

In view of the insignificant change of ultrasonic velocity and amplitude of the concrete under low load, the ultrasonic weighted spectrum parameter obtained from wavelet treatment is taken as the intermediate index during load monitoring of pre-stressed cable. The rating curve of the weighted wave spectrum parameter and load on the concrete anchored pier during pretension of pre-stressed cable is standardized. Based on those standardized curves, the pre-stress of cable is calculated by the ultrasonic monitoring data of concrete anchored pier. The application result of this technology to a slope project shows that when load change exceeds 50 kN, the change of weighted wave spectrum parameter is obvious and this can reflect the change course of the loss of pre-stress. The ultrasonic testing results have a good agreement with load sensor results.