Ground Penetrating Radar

What Makes GPR Unique?

Unlike drilling or excavation, GPR provides a non-destructive window into the Earth. From concrete bridges to ancient ruins, from hidden pipelines to aquifers, GPR reveals what lies beneath — quickly, safely, and in high resolution.  

Our Edge

Dual-Antenna Power – 250 MHz for depth, 500 MHz for detail.

3D Mapping & Visualization – transform profiles into volumetric models.

Smart Processing – advanced filters, imaging, and AI-powered insights.

Integrated Approach – combine with seismic, electrical, and magnetic methods for a complete picture.

Experienced Geophysicists and Geologists. 

Where We Make a Difference

Building Tomorrow – assessing roads, bridges, and tunnels for safer infrastructure.

Smart Cities – locating utilities before a single trench is dug.

Water & Environment – tracing aquifers, mapping soil health, identifying contamination zones.

Heritage – protecting archaeological treasures without disturbing them.

Mines & Energy – scanning for voids, shallow deposits, and safe operations.

Security – detecting tunnels, UXOs, and hidden threats.

Join the Journey

At GeoIntel, GPR is more than a tool — it’s a vision of exploration without destruction. Whether you are an industry partner, a researcher, or an innovator, let’s collaborate to uncover what lies beneath.

Problem Statement 

Reinforced concrete culverts are critical components in transportation and drainage infrastructure, ensuring safe water conveyance and load transfer. Over time, these structures are subjected to traffic loading, environmental exposure, moisture ingress, chloride penetration, and material fatigue, which may lead to deterioration, corrosion of reinforcement, void formation, and loss of serviceability.

Conventional inspection methods such as visual surveys or coring are often invasive, time-consuming, and limited in scope, failing to capture the internal condition of the culvert in a holistic manner. As a result, there is a pressing need for non-destructive, high-resolution, and rapid assessment techniques that can provide actionable insights into the structural health and durability of culverts for asset management and preventive maintenance planning.

Overview

Ground Penetrating Radar (GPR) was deployed for a non-destructive evaluation (NDE) of a reinforced concrete culvert to assess its structural integrity and support preventive maintenance planning. The survey covered 144.5 m² with a high-density 10 cm grid spacing, ensuring comprehensive coverage and fine-scale resolution.

Methodology

A GPR system with a 500 MHz central frequency and 250–750 MHz bandwidth was employed to optimize the depth–resolution tradeoff required for infrastructure investigations. A total of 260 radargrams were acquired and processed using advanced 2D and 3D imaging workflows, including filtering, migration, amplitude analysis, and volumetric reconstruction.

Key Findings

• The processed dataset yielded critical insights into culvert condition and performance:

• Rebar Mesh Mapping: High-resolution imaging of embedded reinforcement, including rebar spacing assessments and concrete cover thickness estimation.

• Interface Characterization: Clear delineation of the asphalt–concrete contact zone.

• Material Degradation Mapping: Identification of localized deterioration zones, voids, and delamination features within the slab.

• Corrosion Potential Zones: Detection of anomalous reflections indicative of possible moisture ingress and early-stage corrosion risks.

• Structural Elements: Precise localization of abutments and supporting walls, aiding in load-bearing capacity assessment.

Engineering Impact

This investigation enabled:

• Condition-Based Monitoring (CBM): Establishing baseline structural health data for future comparative studies.

• Serviceability Evaluation: Verifying functionality of structural components relative to design intent.

• Life-Cycle Extension Planning: Providing data-driven recommendations for targeted rehabilitation and preventive maintenance strategies.

• Compliance with Standards: Workflow aligned with ASTM D6087 guidelines for GPR in concrete evaluation.

Conclusion

The study demonstrates GPR’s effectiveness as a non-invasive diagnostic tool for civil infrastructure. By integrating structural integrity assessment with quantitative deterioration mapping, the methodology enhances decision-making for long-term asset management and infrastructure resilience.

Problem Statement 

Reinforced concrete culverts are critical components in transportation and drainage infrastructure, ensuring safe water conveyance and load transfer. Over time, these structures are subjected to traffic loading, environmental exposure, moisture ingress, chloride penetration, and material fatigue, which may lead to deterioration, corrosion of reinforcement, void formation, and loss of serviceability.

Conventional inspection methods such as visual surveys or coring are often invasive, time-consuming, and limited in scope, failing to capture the internal condition of the culvert in a holistic manner. As a result, there is a pressing need for non-destructive, high-resolution, and rapid assessment techniques that can provide actionable insights into the structural health and durability of culverts for asset management and preventive maintenance planning.

Overview

Ground Penetrating Radar (GPR) was deployed for a non-destructive evaluation (NDE) of a reinforced concrete culvert to assess its structural integrity and support preventive maintenance planning. The survey covered 144.5 m² with a high-density 10 cm grid spacing, ensuring comprehensive coverage and fine-scale resolution.

Methodology

A GPR system with a 500 MHz central frequency and 250–750 MHz bandwidth was employed to optimize the depth–resolution tradeoff required for infrastructure investigations. A total of 260 radargrams were acquired and processed using advanced 2D and 3D imaging workflows, including filtering, migration, amplitude analysis, and volumetric reconstruction.

Key Findings

• The processed dataset yielded critical insights into culvert condition and performance:

• Rebar Mesh Mapping: High-resolution imaging of embedded reinforcement, including rebar spacing assessments and concrete cover thickness estimation.

• Interface Characterization: Clear delineation of the asphalt–concrete contact zone.

• Material Degradation Mapping: Identification of localized deterioration zones, voids, and delamination features within the slab.

• Corrosion Potential Zones: Detection of anomalous reflections indicative of possible moisture ingress and early-stage corrosion risks.

• Structural Elements: Precise localization of abutments and supporting walls, aiding in load-bearing capacity assessment.

Engineering Impact

This investigation enabled:

• Condition-Based Monitoring (CBM): Establishing baseline structural health data for future comparative studies.

• Serviceability Evaluation: Verifying functionality of structural components relative to design intent.

• Life-Cycle Extension Planning: Providing data-driven recommendations for targeted rehabilitation and preventive maintenance strategies.

• Compliance with Standards: Workflow aligned with ASTM D6087 guidelines for GPR in concrete evaluation.

Conclusion

The study demonstrates GPR’s effectiveness as a non-invasive diagnostic tool for civil infrastructure. By integrating structural integrity assessment with quantitative deterioration mapping, the methodology enhances decision-making for long-term asset management and infrastructure resilience.

Problem Statement

Underground manholes and inspection chambers are vital for drainage, utility access, and maintenance. However, their depth, extent, and connectivity are often poorly documented, posing risks during construction, retrofitting, or urban expansion. Conventional intrusive methods are disruptive, whereas a non-destructive, high-resolution approach is essential for safe and precise infrastructure assessment.

Overview

At IIT Tirupati campus, a Ground Penetrating Radar (GPR) survey was conducted to investigate two different manholes and their surrounding subsurface conditions. The study aimed to map the depth, extent, internal structure, and connecting utilities, while also characterizing the geotechnical layers around the chambers.

Methodology

• System Configuration: A 250 MHz ultra-wideband antenna was employed, providing deeper penetration and wide-frequency coverage.

• Survey Design: Data acquisition was performed on 3D grids with 25 cm line spacing, enabling detailed volumetric imaging and depth slicing.

• Processing Workflow: Advanced 2D/3D imaging, time-slicing, and amplitude analysis were applied to highlight manhole geometry, utilities, and surrounding strata.

Key Findings

• Manhole Geometry: Both manholes were clearly mapped in terms of depth and lateral extent, with volumetric estimates generated.

• Utilities and Connectivity: Subsurface pipelines connecting the manholes were identified, including utilities located beneath concrete reinforcement layers, which are typically difficult to detect.

• Material Stratigraphy: Multiple subsurface layers were distinguished, including reinforced concrete, unsettled soil, and underlying bedrock at greater depths.

• Airwave Reflections: Strong reflections from nearby building walls were recorded, producing distinct patterns due to indoor signal propagation.

• Depth-Slice Imaging: The dense 3D grid and ultra-wideband configuration enabled clear visualization of manholes, chambers, and connecting utilities in successive depth slices.

Engineering Impact

• The survey demonstrated the ability of GPR to:

• Deliver accurate mapping of manholes and chamber volumes.

• Detects deep-seated and hidden utilities beneath reinforced concrete layers.

• Provide layer-specific geotechnical insights for soil and foundation conditions.

• Support infrastructure planning, rehabilitation, and safe excavation.

Conclusion

This case study establishes GPR as a powerful tool for non-invasive investigation of underground manholes and chambers, offering detailed information on geometry, connectivity, and surrounding materials. The combination of 250 MHz ultra-wideband antenna and 3D grid survey design proved particularly effective for resolving complex subsurface conditions within a campus infrastructure setting.

Problem Statement

Optical Fiber Cables (OFCs) form the backbone of digital connectivity, but their non-metallic composition and installation within plastic conduits make them extremely difficult to detect with conventional geophysical tools. In wet soil conditions, where radar signal attenuation is high, mapping such cables becomes even more challenging. A non-destructive technique was required to attempt detection of OFC alignments while simultaneously assessing subsurface soil conditions for site planning.

Overview

A 3D Ground Penetrating Radar (GPR) survey was carried out at the IIT Tirupati campus using 250 MHz and 500 MHz ultra-wideband antennas to investigate the presence of buried OFC cables, while also mapping surrounding soil strata and embedded obstructions.

Methodology

• System Configuration: Dual-frequency acquisition with 250 MHz (deep penetration) and 500 MHz (higher resolution) antennas.

• Survey Design: Dense 3D grid acquisition to enhance imaging and provide volumetric subsurface visualization.

• Site Conditions: Wet soil environment, posing challenges due to high dielectric losses and signal attenuation.

Key Findings

• Subsurface Stratigraphy: Distinct layering of soil strata was mapped, along with reflections from embedded boulders and heterogeneities.

• OFC Cable Response: Due to the non-metallic nature of the OFC and installation within plastic conduits at ~5 m depth, clear GPR signatures could not be obtained.

• Depth Limitations: Signal attenuation in wet soils further restricted the visibility of thin dielectric targets at such depths.

• Complementary Potential: The survey highlighted the importance of multi-method approaches, such as combining GPR with electromagnetic induction (EMI) or ground-truthing techniques, for reliable detection of non-metallic utilities.

Engineering Impact

• Provided valuable insights into soil stratigraphy and boulder distribution for geotechnical planning.

• Demonstrated the limitations of GPR in detecting deep, non-metallic OFC cables in wet soil environments.

• Reinforced the need for integrated geophysical methods for comprehensive underground utility detection.

Conclusion

While GPR effectively mapped soil layers and buried obstructions, the detection of non-metallic OFC cables within plastic conduits at 5 m depth proved infeasible under wet soil conditions. This study underscores both the capabilities and limitations of GPR, highlighting the necessity of multi-technique surveys for complete underground utility mapping in complex environments.