Method for determining grouting defect duct position of prestressed concrete bridge

The invention provides a method for determining the position of a grouting defect pore channel of a prestressed concrete bridge. The projection position of the center of the pore channel on a test surface is determined on the concrete surface of the prestressed concrete bridge according to a design drawing; arranging a vertical measuring point and a measuring line in a direction vertical to the trend direction of the predicted pore channel; testing the elastic wave velocity of concrete near the hole channel by using a nondestructive testing instrument, and testing and judging the grouting condition of the hole channel in the direction vertical to the hole channel by using the wave velocity; drawing a horizontal measuring line and a measuring point along the trend direction of the hole channel on the basis of determining the position of the grouting defect measuring point; a nondestructive testing instrument is used for testing along the horizontal measuring line, and the hole channel grouting quality is judge