桥梁水中基础振动波法无损检测技术研究

Non-destructive Testing by Oscillation Wave for Bridge Foundation in Water

结合桥梁水中基础的构造特点,进行了振动波法检测技术研究。首先研发了水下旁听法,即在承台、系梁适当位置敲击,在水下结构物旁侧的水体中吊装检波器,通过拾取在结构中下传的弹性纵波和纵波在水中横向传播的时域振动信号,主要利用时域振动信号首波走时对结构的质量状态进行分析。其次,针对桩基等结构物,研发了单孔纵波法,即在结构顶面上通过力锤敲打激振产生弹性纵波,在结构物上直接钻孔或在其外侧设置孔道,通过拾取在结构中下传的弹性纵波和从结构物底面(包含缺陷断面)产生的反射波的时程,利用时域振动信号首波走时对结构的质量状态和长度进行分析。实体检测结果表明,这两种检测方法都能反映基础构件内部状况。

The oscillation wave testing technology for bridge foundation in water is discussed. At first,the method called parallel seismic test in water is put forward. In this way,shock at certain part of platform or beam over pile tops is finished,the detector in water near platform or beam side face would collect the longitudinal elastic wave and the time domain vibration signal propagating through the structure and water,and the structure state is analysed by travel time of first peak of the signal at different collecting place.Second,as for bridge foundation in water,another method called longitudinal wave method in single testing channel is developed. In such method,shock is finished at top of structure,and longitudinal elastic wave would be collected in testing channel drilled-in or out of the structure. The longitudinal elastic wave transformed downward in the structure and the reflected wave from the toe or defect section of the structure are collected. And the structure state or depth are analyzed by first peak in time domain vibration waves. The entity detection result shows that the inner state of foundation structure could be tested by both methods.