Application of Ground-Penetrating Radar Technology in Urban Underground Space Exploration

Seeing Below the Surface: Innovative Applications of Ground-Penetrating Radar for Urban Safety

As urbanization accelerates, the development and use of underground spaces are increasing, bringing with them public safety threats such as road collapses and damaged utility lines. Acting as a "CT scanner" for urban underground infrastructure, Ground Penetrating Radar (GPR) technology—with its high efficiency, non-destructive nature, and precision—is becoming essential to protecting the city's vital lifelines.

Ground-penetrating radar (GPR) works by transmitting high-frequency electromagnetic waves into the ground via a transmitting antenna. When these waves encounter subsurface media with different electrical properties—such as pipelines, voids, or water bodies—they reflect back to a receiving antenna. The captured signals are processed by a computer to generate images of the underground structure. This technology not only accurately locates metallic pipelines but also effectively addresses the challenge of detecting non-metallic pipes (e.g., plastic and concrete) that traditional equipment often misses.

In urban road safety maintenance, ground-penetrating radar (GPR) has shifted from "reactive repair" to "proactive prevention." In 2024, Xiangzhou District in Zhuhai and Nanchang City deployed radar-equipped inspection vehicles for off-peak operations. These vehicles can perform comprehensive road health assessments while driving—without closing lanes—precisely identifying hidden defects such as subgrade voids, soil loosening, and water accumulation. Suqian further integrated GPR data into its Urban Lifeline Safety Supervision Platform, leveraging 5G networks for real-time alerts. This approach successfully warned of multiple road cavities and was recognized as a national digital government standard case. Similarly, in Zhuzhou, Hunan, technicians scanned 18 major roads—including Renmin Road and Tiedong East Road—using GPR technology. They identified 23 road defects, including 2 severe cavities, providing scientific evidence for timely repairs and preventing collapse incidents.

Ground-penetrating radar (GPR) also excels in underground utility mapping and updates. In Guiyang's "sponge city" initiative, GPR was used for blind surveys of the underground network, accurately determining pipe depth and stratification while successfully identifying buried pipes within drainage ditches and water-saturated zones. For renovating older residential communities, GPR acts as a "X-ray," revealing hidden defects. In one such project, radar detected multiple concealed leaks in water supply lines, enabling targeted excavations that avoided large-scale road disruption and minimized impact on residents. Additionally, when integrated with BIM technology, GPR data can generate 3D models of underground utilities, supporting comprehensive urban redevelopment and ensuring precise alignment between new and existing infrastructure.

From early warning of road voids to precise mapping of complex utility networks, ground-penetrating radar (GPR) is redefining how urban underground spaces are managed. With breakthroughs in domestic core components and the integration of AI algorithms, GPR systems are becoming smarter and more portable, providing robust underground data support for building safe, resilient modern cities.