| The paper introduces the laws of acoustic propagation in solids,experimental measuring equipments and several deciding methods of sound wave inspection pile from the basic principle and phylogeny of testing cast-in-situ piles by using ultrasonic Transmission method,based on the cast-in-situ piles testing in the Pingtan Kaikyo Bridge project.It gets regression equation between pipe diameter and wave velocity and variational laws by analyzing wave velocity and amplitude in different tube pitch,according to the measured data in engineering.Then comparing with laboratory test results from Nanjing hydraulic academy of sciences,it shows the wave velocity test results should be revised in practical projects because of the different results but same curve trend.Secondly,it obtains regression equation and variational laws of amplitude with different distance measurement: the slope changes little in middle, but a little larger in both ends in the measuring distance when a little change amplitude, base on amplitude research. Then coefficient regression equation of amplitude is presented,which indicates the acoustic energy changes faster in shorter measuring distance and the middle acoustic energy change slower in longer measuring distance but faster when measuring distance is greater than critical value.In the last,the cast-in-place pile foundation of Pingtan straits bridge has field test by using ZBL-U520 nonmetal ultrasound detector.Through sound time,sound amplitude and sound velocity,it analyzes some typical pile foundation measured curve of Pingtan straits bridge (Complete pile,sandwich pile,low intensity,pile breaking pile),judges defect position and evaluates integrity of pile foundation in the same time.From the test results,the author get conclusion as follows:the ultrasonic transmission method can judges several defects of long pile and the it will be more reliable to test the quality of concretes by using ultrasonic transmission method.
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