GPR Surveys

PAS128, developed by the British Standards Institution (BSI) and the Institution of Civil Engineers (ICE), is the current standard for underground utility detection. It ensures the reliable and consistent sharing and delivery of all information related to underground utilities. With various detail categories available, PAS128 applies to engineers, construction businesses, project managers, utility owners, and surveying companies, setting out best practices for compliant underground utility surveys.

This highly accurate and detailed survey level is generally used in areas known to be densely populated with services, minimising danger, conflict, delays, and disruption to your project.

GPR surveys are valuable for a wide range of industries and applications, including construction and infrastructure development; utility mapping and maintenance; environmental site assessments and remediation; archaeology and cultural heritage preservation; forensic investigations and law enforcement; mining and geological exploration; and agriculture and precision farming. 

GPR survey results can be presented in various formats depending on the project requirements and client preferences. Common deliverables include 2D cross-sectional images (radargrams) showing the subsurface features along survey lines; 3D models or depth slices that provide a volumetric representation of the subsurface; utility maps or CAD drawings that integrate GPR data with other survey information; and detailed reports describing the survey methodology, data interpretation, and key findings. 

GPR offers several key advantages over traditional utility mapping methods: it is non-invasive and non-destructive, allowing for surveys in sensitive areas without excavation; detects both metallic and non-metallic utilities, providing a more comprehensive picture of underground services; enables rapid data collection for efficient survey of large areas; provides continuous, high-resolution data that can be interpreted in real-time or post-processed for detailed analysis; and is cost-effective compared to excavation or other invasive methods. 

The penetration depth of GPR depends on several factors, including the antenna frequency, soil type, and moisture content. Lower frequencies can penetrate deeper but provide lower resolution, while higher frequencies offer better resolution but shallower penetration. In general, GPR can reach depths of several meters in ideal conditions, but penetration may be limited in clay-rich or saturated soils. 

GPR surveys can detect a wide range of underground features, including non-metallic utilities such as plastic water and gas pipes, fiber optics, and drainage systems; metallic utilities like electrical cables and steel pipes; voids, cavities, and sinkholes; changes in soil composition and stratigraphy; and buried objects, foundations, and storage tanks. 

A Ground Penetrating Radar (GPR) survey is a non-invasive geophysical technique that uses electromagnetic waves to create images of subsurface features. GPR emits high-frequency pulses into the ground and analyzes the reflections to detect underground objects, changes in soil composition, and other anomalies.