The acoustic pipe can be directly fixed on the inside of the steel cage: The fixing method can be welding or binding, and the pipes should generally remain parallel – if the test results require an assessment of the concrete strength at each measurement point, the non-parallelism should be controlled below 1‰. When placing the steel cage into the pile hole, prevent it from twisting.
Pipe sections are generally installed with steel reinforcement cages, and the joints between sections can be achieved using reverse threaded sleeve connections or pipe welding. If corrugated pipes are used, a larger diameter corrugated pipe sleeve can be utilized for connection, and the ends of the sleeve should be sealed with tape. Regardless of the jointing method, it must ensure that no slurry leakage occurs under high static water pressure. The inner wall of the joints should be smooth and free of protrusions like slag or burrs to prevent hindrance of the probe's movement. The bottom of the acoustic measurement pipe should also be sealed, and after installation, the top opening should be blocked with a wooden plug to prevent foreign objects from falling into the hole during concrete pouring, which could lead to blockage of the channel.