Abstract:In ultrasonic test for pile, the variety of embedded pile is always a problem for further analysis. In this paper, a new method for amending the time interval in ultrasonic test of pile is studied. This method is easy to be understood. The key of this method is to assume that the varying trend of time interval represents the trend of pipe. With this method, we can calculate the real ultrasonic velocity of concrete and easily locate the weak part of the pile.