为提高地铁预应力桥梁孔道灌浆密实度检出率从而保障地铁运营安全，研究了针对预应力桥梁隐蔽病害的超声波检测技术。根据实际情况，分别设计了不同箍筋和配筋率的预应力混凝土试验梁作为检测试件，在试件中预设了不同材料类型及尺寸的人工缺陷进行对比。试验结果表明：超声波检测技术对地铁预应力桥梁孔道缺陷的检测效果较好，最小可以检测出尺寸为5 cm的不密实缺陷。在北京某地铁线路的预应力桥梁进行了现场试验，结果与模拟试验结果基本一致。

In order to improve the detection rate of the grouting density of the pre-stressed concrete beam and ensure the safety of the operation, the ultrasonic wave method techniques for hidden hazards is studied. According to the actual situation of the pre-stressed concrete beam of the subway, different stirrup and reinforcement ratio are designed in the test beam respectively, and artificial defects of different material types and sizes are preset in the test piece. The results show that the ultrasonic method has good effect on the flaw detection of the subway pre-stressed beams, and the minimum defect within the size of 5 cm can be detected. The field test results of pre-stressed beam in one line in Beijing are in agreement with the simulation test.