Application of Low Strain Method Combined with Coring in Pile Length Estimation
The low strain method can be used to estimate the integrity along the pile shaft and the length of pile.When the test results of pile length are in question,the coring method can be used to verify.When the pile lengths of the entire project are tested,a representative value of the wave velocity can be determined by combining the low strain method and the core drilling method.When the wave velocity of the pile is greater than the representative value of the wave velocity,the length of the pile can be determined.Combined with engineering examples,this paper introduces the combination of the low strain method and coring method to verify the pile length detection of all CFG piles on a composite foundation.The low strain method and coring method can demonstrate their own advantages in the process of the pile length estimation and complement each other;The actu-al strength grade and the elastic modulus of the pile concrete can be determined by the compressive strength test of the cored sample.The representative value of the wave velocity can be calculated according to the theoretical formula of the relationship between the wave velocity of concrete and the elastic modulus as well as mass density.The theoretical calculation results and the field test results can verify each other and achieve the good results.
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