What Are The Main Inspection Methods For Finned Tubes

(1) Double pipes shall be buried at the pile diameter of 0.6-0.8m; Three pipes shall be buried with pile diameter of 0.8-2.0m; Four pipes shall be buried for pile diameter above 2.0m, and three pipes can be buried for pile foundation according to the specific situation of Chifeng Bridge.
(2) The acoustic detection pipe should be steel pipe, plastic pipe or steel corrugated pipe, and its inner diameter should be 50~60mm. The connection of the detection pipe shall be smooth and the pipe orifice shall be more than 100mm higher than the pile top. The height of each detection pipe orifice shall be the same. The lower end of the pipe shall be closed and the upper end shall be covered. There shall be no foreign matter in the pipe and no damage to the pipe body.
(3) The detection tubes can be welded or bound on the inside of the reinforcement, and the detection tubes should be parallel to each other.
On-site inspection of finned tube
(1) Determine the delay time t from the acoustic monitor to the receiving system before on-site detection. And calculate the correction value of sound time.
(2) During measurement, the transmitting and receiving probes shall rise and fall synchronously at the same elevation or maintain a fixed elevation difference.
(3) The distance between measuring points is 40cm, and it will be densified to 20cm when abnormality is found
(4) Select the appropriate transmission voltage and amplifier gain, and keep them unchanged during the test.
(5) Display and record the time history curve of the received signal in real time.
(6) The multiple finned tubes are fully combined with two test sections, and the multiple sections are tested respectively.
(7) After the test of each group of test tubes, 10% of the test points shall be randomly repeated, and the relative standard deviation of sound time shall not be greater than 5%; The relative standard deviation of wave amplitude shall not be greater than 10%.