Core Insights - The technology addresses the long-standing challenge of detecting internal defects in tunnel structures, particularly in the Ji-Tai Expressway where the bridge-tunnel ratio is as high as 50% with six tunnels totaling 13 kilometers [2][4] - The patented technology utilizes air-coupled impact echo principles, overcoming limitations of traditional detection methods by employing air as a coupling medium for non-contact internal defect detection [2] - The system captures leakage waves that carry critical internal information, allowing for rapid and accurate assessment of tunnel structure quality by analyzing frequency characteristics [2] Summary by Sections - **Technology Innovation** - The patented technology enables non-contact internal defect detection using air as a coupling medium, which is a significant advancement over traditional methods [2] - It captures leakage waves from stress waves in tunnel linings, providing essential data for assessing structural integrity [2] - **Application and Benefits** - The device demonstrates significant advantages in the complex tunnel environment of the Ji-Tai Expressway, reducing economic costs for long-distance, multi-tunnel inspections while enhancing detection quality and efficiency [4] - This innovation supports the lifecycle management of tunnel structures, ensuring safe and high-quality operations for the Shandong regional management center and setting a benchmark for similar infrastructure across the country [4]