Research On The Application Of Crosshole Sonic Logging In The Test Of Foundation Piles Quality

Crosshole sonic logging is a kind of foundation pile test method which is used to test to pile integrity acoording to eradiate and receive waves via pipes of ultrasonic buried beforehand and to analys the measured ultrasonic's frequency, amplitude and the other acoustic parameters which relative changed during the propagation in concrete. As a popular foundation non-destructive inspect technology, the Crosshole sonic logging has eminent performance such as high testing veracity, convenient field operation, and not effected by the characteristics of pile length and slenderness. The general other test methods is incapable assimilates to crosshole sonic logging.First, the dissertation from the fundamental and method of crosshole sonic logging summarizes this method's fundamental theory, instruments and inspect technology, generally reviews the relation betweene acoustic parameters and the concrete quality, establishes the corresponding relations between acoustic parameters and pile defect according to contrast the various acoustic parameters. Then, it gives a series discussions towards the test data's analyses and the result determinant, generally studies how to estimate the pile defection and the incline problem of pipe of ultrasonic. Research result indicates the pipes that can't keep parallel will bring a lot of changes and influence the judgement, therefore it is necessary to correct the problem of incline measured distance with curve-fitting procedures. In addition, the existing assessing method of pile quality which is deficient commonly adopt the single criterion or a simple assembled criterion,not colligates the three or more factors to be taken into account and. In order to correct this method's deficiency, the dissertation makes use of the fussy mathematics in the system of the quality of pile testing. Through the compositive assessing method of the fuzzy mathematics, the parameters (wave amplitude, wave velocity, and wave frequency) of the ultrasonic are construed, the result is gained. The fussy mathematics method makes up for the existing PSD-V-A method'sdrawback, certainly, enhances assessing result's reliability. Simultaneity embined to the practice engineering, we compares the fussy mathematics method to PSD-V-A method in order to prove that the method is effective.The dissertation used the fuzzy synthesis appraisement method which is applied in pile concrete quality inspection to synthesis assess lots of piles and obtains a successful testing effect. Compared with the existing PSD-V-A method, the result of two method are consistent. The two method have them own's excellence. The PSD-V-A method is brief and straight, but depends most on scrutator's experiences. The fuzzy synthesis appraisement method based on PSD-V-A method and fuzzy mathematics is effective but complex. The two can complement each other. Considering them respective characteristic, it is suggested that generally we uses the PSD-V-A method to analyse foundation piles' quality and uses fuzzy synthesis appraisement method to assess the complicated problem.