Rapid analysis method for foundation pile integrity coefficient by introducing pile-soil interaction
A technology with complete coefficients and analysis methods, applied in electrical digital data processing, instruments, geometric CAD, etc., to solve problems such as errors, reduced accuracy of analysis results, dimensional wave fields, sensor frequency characteristics, and hammering and other factors
Active Publication Date: 2021-04-16
WUHAN INSTITUTE OF TECHNOLOGY
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Problems solved by technology
[0004] Method 2: In order to introduce the effect of pile-soil interaction on wave propagation, the particle vibration velocity response test curve is fitted and analyzed. However, the test curve is easily affected by factors such as the three-dimensional wave field at the pile top, the frequency characteristics of the sensor, and hammering. The test curve Some responses do not correspond to the reflected waves of the pile wave impedance. During the fitting analysis, analysts need to have high professional knowledge to filter and correct the test curves to reduce the influence of these factors on the test curves. Otherwise, The changes in the test curve related to these influencing factors will be mistakenly fitted as the reflected wave response of the pile body, resulting in a decrease in the accuracy of the analysis results, or even errors
[0005] In view of the fact that the analysis of the integrity coefficient of the foundation pile based on the peak value ratio of the reflected wave and the first wave of the test curve does not consider the influence of pile-soil interaction and the waveform fitting analysis method is easy to mistake the abnormal response curve caused by other factors as the effective reflected wave response fitting problem, this paper The purpose of the invention is to provide a quick analysis method that can introduce the influence of pile-soil interaction, through the attenuation correction of the particle vibration velocity of the reflected wave, and obtain the integrity coefficient of the foundation pile from the peak value ratio of the corrected reflected wave and the first wave, and improve the analysis accuracy of the integrity coefficient of the foundation pile
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Embodiment 1
[0114] Embodiment 1, step 1, a reduced-diameter model pile length L=8m, pile top cross-section diameter D=2R=0.4m, a necking is set apart from pile top 4m-4.5m range, and pile surrounding soil is backfill soil; The accelerometer is pasted on the center of the pile with plasticine In the vicinity, hit the center of the pile with a hand hammer, and record the vibration acceleration response of the particle by the pile dynamic tester. The sampling time interval Δt=2×10 -5 s, the particle vibration velocity response test curve is obtained by integrating the acceleration response curve, the particle vibration velocity response test curve is subjected to 2000Hz low-pass filtering, and the particle vibration velocity response test curve after processing is shown in figure 2 ;
[0115] Step 2. From the time difference between the first wave of the test curve and the peak-to-peak value of the reflected wave at the bottom of the pile and the length of the pile, the average wave veloc...
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The invention discloses a rapid analysis method for a foundation pile integrity coefficient by introducing pile-soil interaction, and relates to the field of foundation pile structure integrity testing. The method comprises the steps of step 1, obtaining a mass point vibration speed response curve of the pile top of a detected foundation pile; step 2, according to the corresponding time difference between the head wave in the mass point vibration speed response curve and the mass point vibration speed peak value of the first reflected wave of the pile body, determining the position between the reflecting surface and the pile top surface; step 3, analyzing a reflection surface foundation pile integrity coefficient without considering the pile-soil interaction influence through a ratio of a mass point vibration velocity peak value of a first reflection wave of a pile body to a mass point vibration velocity peak value of the head wave; and step 4, introducing the influence of pile-soil interaction on wave propagation according to the pile periphery soil property parameters, and correcting the reflection surface foundation pile integrity coefficient. According to the method, the problem that the pile-soil interaction influence is not considered in the reflecting surface foundation pile integrity coefficient analysis method based on the amplitude ratio can be solved.
Description
technical field [0001] The invention relates to the field of structural integrity testing of foundation piles, in particular to a quick analysis method for foundation pile integrity coefficients with the introduction of pile-soil interaction. Background technique [0002] Foundation piles are widely used in engineering foundations such as urban buildings, bridges, and docks. During the construction process of foundation piles, quality problems such as separation of aggregate and concrete, mud inclusion, shrinkage, cracks, and fractures often occur. And safety is very important. These quality problems will lead to relative changes in the section wave impedance of the pile body. The relative change in the section wave impedance of the pile body is often detected by the percussion echo method. Downward propagation, when the wave impedance of the pile body changes relatively, the wave will be reflected at the interface where the wave impedance changes. Use the acceleration sen...
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IPC IPC(8): G06F30/13G06F30/20G06F119/14
Inventor 柴华友
Owner WUHAN INSTITUTE OF TECHNOLOGY