In-pipe GPR surveys inform on compaction of earthworks

SSI Test, Inspect, Consult was recently appointed to perform a Ground Penetrating Radar (GPR) survey on 2 x Ø750mm Asbestos Cement syphon pipes as part of a post relining project.

Purpose of Ground Penetrating Radar Survey

The purpose of the survey was to determine, use a non-destructive survey technique, what problems, voids and soils compaction existed around the pipe and advise where applicable of suitable methods for remedial action dependent on the findings.

The GPR survey was unique in its method as the equipment used including a high-frequency antenna, was not reliant on the contact of the equipment with the pipeline wall and with survey lengths >150m.

Over the 1125m surveys, only four locations were identified with potential anomalies which were suitable for resin injection and ground stabilisation techniques.

This was an excellent opportunity and case study to demonstrate the effectiveness of a pre-project GPR survey to assist in identifying the specification for structural or non-structural liners.