GPR SURVEY SOLUTION
Accuracy of the utility locations and other assessment are important for value engineering and proper planning of relocation of underground costly arrangement. This NDT practice requires selection of proper equipment, planning, data acquisition, processing and decision making deliverables that BPCIPL is at its best.
GPR is a powerful tool being used in engineering investigations to evaluate dams, sea walls, tunnels, pavements, roadbeds, railway embankments, piles, bridge decks, river scour, buildings and monuments. Depending on the type of job, different sets of equipment with different antenna frequencies are being used. GPR is primarily being used for underground utility survey for various infrastructure projects and accordingly the design or relocation is conducted. subsurface utility examination survey (SUE) to locate existing underground services like water/drainage/gas pipeline, power/telecom cables etc Equipped with GPR and EPL.
Solutions
Whether to use ground coupled or air coupled antea and the frequency is selected based on the nature of the project. shallow utility mapping may require any frequency from 600 - 900 MHz and for deep utility mapping it must have any frequency from 80 -160 MHz. The GPR is integrated with RTK DGPS system.
Our team of trained GPR surveyor gathers knowledge about public record, as built documents, and asset owner database for desk study.
Project requirement shall define the required frequency, the time window, the time sampling interval, the station spacing, the antennae spacing, the line location and spacing and the antennae orientation. 2D and/or 3D scans of the site are done based on the quality of data required and available time. 3D display has the obvious advantages, intersections (of pipelines/cables) and layer profiles can be easily identified.
Analysis is done using softwares and interpretation of different underground objects or features are enumerated by our expert geophysicist. In some cases test pits are carried out to correlate between the interpreted features and the utilities. Thus we produce the highest possible accuracy of detection of different objects, be it utilities or different layers.
GPR APPLICATION
Highways
- Determine Pavement Layer Thickness
- Estimate Material Properties
- Identify Stripping Zones within Asphalt
- Detect Subsurface Voids
- Analyze Rutting Mechanisms
- Detect Subsurface Anomalies
- Bridge Deck Delamination
- Rebar and Dowel Bar Locates
Geology
- Geological and hydro-geological investigations including mapping of bedrock topography, water levels,, soils and aggregates and glacial structures
- Controlled Archaeological Test Site
- Railways: thickness measurements of ballast and subballast layers and in evaluation of moisture condition in granular layers. Vehicle mounted GPR is also used depending on project extent and the requirement
Underground Utilities
- Utility Mapping for Designers and Utility relocations
- Foundations, reinforcing bars, cavities, tombs, archaeological artifacts, and animal burrows
- Underground storage tanks
- Subsurface mapping for cables, pipes and other buried structures prior to trench-less operations