Cangzhou Huayang Steel Co

*Price per meter of acoustic pipes for bridge pile foundations



b br Adopts the acoustic transmission method. It lowers the ultrasonic transmitting probe and the receiving probe into different steel pipes that are pre-embedded in the pile body and filled with water. The ultrasonic waves generated by the transmitting probe penetrate the concrete of the pile body through water coupling and reach the receiving probe in another steel pipe, receiving<
b br The probe transmits the received information to the instrument, and evaluates the quality of the pile concrete by comprehensively analyzing the characteristics of the received ultrasonic waves in the concrete: such as the characteristics of sound speed, amplitude, frequency and waveform parameters. Its basic basis is: when there are defects in concrete
b br, the ultrasonic sound speed, amplitude, frequency and waveform parameters are reflected. First of all, when there are defects inside the concrete, a discontinuous medium is formed on the ultrasonic wave transmitting and receiving path. The low-frequency ultrasonic wave will bypass the defects and propagate forward. Within the detection distance, its diffraction reaches the target. The required sound time is longer than the sound time required when ultrasonic waves propagate directly in defect-free concrete, reflecting the reduction in the sound speed of ultrasonic waves. Secondly, due to the presence of defects, when ultrasonic waves propagate in concrete, the sound energy attenuation increases, and the amplitude of the first wave of the received signal decreases. The third is that when there are defects in the concrete, the high-frequency components disappear faster than the low-frequency components, and the frequency of the received signal is always lower than that received by the defect-free concrete through the same range. Finally, due to the complex reflection and refraction of <
b br ultrasonic waves on the defect interface, the phase of sound wave propagation is different, and the superposition result causes the waveform of the received signal to be distorted. Based on this, the internal quality of the concrete can be judged. <
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b br Detection points<
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b br Pre-embedded detection tube: <
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) Pile diameter
Double pipe pile diameter should be buried
Three pipe pile diameter should be buried
Four pipes should be buried above. According to the specific conditions of Chifeng Bridge, piles Three pipes can be buried in the foundation. <
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) The acoustic detection tube should be steel pipe, plastic pipe or steel corrugated pipe, and its inner diameter should be
~
. The joints of the detection tubes should have a smooth transition, and the tube opening should be higher than the top of the pile. The height of the openings of each detection tube should be consistent. The lower end of the tube should be closed and the upper end should be capped. There should be no foreign matter in the tube and the tube body should not be There is damage. <
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) The detection tubes can be welded or bundled on the inside of the steel bars, and the detection tubes should be parallel to each other. <
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) The detection tube should be filled with clean water. <
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b br On-site inspection<
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) Before on-site inspection, measure the delay time from the acoustic monitor to the receiving system
. And calculate the sound time correction value. <
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) During measurement, the transmitting and receiving probes should be raised and lowered synchronously at the same altitude or with a fixed height difference. <
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) The measurement point distance is
, and when an abnormality is found, it is encrypted to <
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) Select the appropriate transmit voltage and amplifier gain , and remain unchanged during the test. <
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) Display and record the time course curve of the received signal in real time. <
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) Combine multiple acoustic detection tubes with two as one detection profile, and complete the detection of multiple profiles respectively. <
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) After the test of each group of detection tubes is completed, the test points should be randomly tested
%, and the relative standard deviation of the sound time should not be greater than the
% amplitude relative standard The difference should not be greater than
%. <
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b br Data compilation<
b br Implementation of "Technical Specifications for Inspection of Building Pile Foundations" (
) <
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b br Determination of pile integrity<
b br Judgment based on the following table<
b br Determination table of pile integrity by acoustic transmission method<
b br Category??
Characteristics<
b br Ⅰ??
There are no abnormalities in the acoustic parameters of each detection section, and there is no abnormality where the sound speed is lower than the lower limit value
b br Ⅱ??
A certain detection The acoustic parameters of individual measuring points in the profile are abnormal, and there is no abnormality of sound velocity lower than the lower limit<
b br Ⅲ??
A certain detection profile has two or more abnormal acoustic parameters of multiple measuring points in succession. The acoustic parameters of the above detection profiles at the same depth measurement points are abnormal. The local concrete sound velocity is abnormally lower than the lower limit value
b br Ⅳ??
Acoustic parameters of multiple measurement points appear continuously in a certain detection profile. Obvious anomalies: The acoustic parameters of two or more detection profiles at the same depth measurement point are obviously abnormal. The sound velocity of the pile concrete is generally lower than the lower limit value, or the first wave cannot be detected or the first wave received signal is severely distorted. <