Experimental Study on Impact Echo Method for Detecting the Quality of Floating Pouring in Immersed Tube Tunnels

The floating pouring of immersed tube tunnels is greatly affected by the multi-layer water stop structure and the uncontrollable quality of water waves, and quality inspection is needed to ensure the mechanical and sealing properties of the joint surface of the immersed tube joints. The impact echo method, as a reliable, efficient, and stable concrete detection method, has great application prospects in the quality inspection of floating pouring in immersed tube tunnels. Therefore, this article conducted a full-scale model test study on the impact echo method to detect the floating pouring quality of immersed tube tunnels. The results show that the impact echo method can effectively identify defects such as void separation and poor pouring at the joint surface of the floating pouring immersed tube tunnel. When the pouring quality is good, when the measuring line passes through the rubber waterstop below, the depth corresponding to the main peak frequency is the depth of the rubber waterstop. When it does not pass through the rubber waterstop, the depth corresponding to the main peak frequency is the thickness of the component. When there are quality defects, the main peak frequency corresponds to the depth of the defect location.