Method for detecting integrity of high flat bed pile under existing building through overtone response function method

Abstract

The invention discloses a method for detecting integrity of a high flat bed pile under an existing building through an overtone response function method. The method for detecting the integrity of the high flat bed pile under the existing building through the overtone response function method comprises the following steps of (1) collecting data; (2) analyzing the collected data through the overtone response function method; (3) judging the length and the integrity of the high flat bed pile, wherein speed signals and strength signals of a certain position of the upper portion of a pile body are acquired by applying shock excitation on the top face of a flat bed over a tested foundation pile, and an overtone response function of the position is calculated by using the overtone response function method to analyze the integrity of the pipe body. When the shock excitation is applied to the top face of the flat bed of the foundation pile, for the certain position of the foundation pile, firstly, downward waves are generated, then the downward waves are reflected by the file bottom (flaws) to form upward waves, the change of the upward waves relative to the downward waves is only related to the pile and soil which are below the position, the overtone response function is obtained by dividing the Fourier transformation of the upward waves by the Fourier transformation of the downward waves, the integrity of the part, below the position, of the pile body is judged through the overtone response function, and the influences of the upper portion of the pile body can be avoided.

Description

technical field [0001] The invention relates to a technology for detecting the integrity of high cap piles under existing buildings, in particular to a method for detecting the integrity of high cap piles under existing buildings using a pan frequency response function method. Background technique [0002] High cap pile foundation is a common foundation form in bridges, docks and other projects. In recent years, natural disasters have occurred frequently in various countries around the world. After each large-scale disaster such as destructive earthquakes, landslides, and tsunamis, many bridges, The wharf will be damaged and damaged in different degrees, and these damages and damages will not only occur in the structure of the bridge and the upper part of the wharf, but also in the foundation part of the lower part. On the other hand, because some of the pile foundations of high-cap pile foundations such as bridges and wharf piles are exposed on the ground, they are easily d...

AI Technical Summary

Problems solved by technology

[0003] The routine detection methods of foundation pile quality include single pile static load test, low strain reflection wave method, acoustic wave transmission method, and drilling coring method. When using conventional detection methods, the pile top is usually required to be a free end. Pile, the conventional method is difficult to operate

In addition, for the side hole transmitted wave method for the detection of existing building foundation piles, holes need to be drilled near the pile side and each pile needs to detect dozens or even hundreds of measuring points, the detection efficiency is relatively low, and the cost Higher, not suitable for large-scale quality surveys, especially for docks and bridge piles on water, the actual operation is difficult, and for longer piles, the inclination of the borehole will lead to unreliable test results

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