Concrete Scanning - Ground Penetrating Radar (GPR)
Southern Geophysical has been scanning concrete floors, walls, ceiling, columns, beams, footings, roofs, and other structures with radar since 2004. We have the depth and experience for all jobs.
Building owners and engineers trust Southern Geophysical to locate subsurface infrastructure prior to cutting or coring in concrete. We minimize cost, reduce hazards and allow structural concerns to be addressed.
Southern Geophysical owns a range of radar systems to tackle all sites and conditions. Where needed, Southern Geophysical combines technologies and disciplines, beyond basic concrete scanning.
We can undertake
- Slab thickness estimates, both for suspended slabs and slab-on-grade
- Rebar pattern location and mapping services
- Detection of post-tension cables
- Locating metallic and non-metallic pipes and conduits
- Detecting voids and concrete problems
- Locating pipes and cables including those buried within/under slab-on-grade concrete pads
- Reporting quantitative data for engineering applications
Pile and Structural Testing
Southern Geophysical has over 10 years experience carrying out pile and structural testing.
Pile testing is used to assess new and existing building piles, bridge abutments, foundations and other structures. There are a number of pile testing methods that can be used, depending on the requirements of the project. Some of the more common methods are:
- Low Strain Integrity
- Cross-hole Sonic Logging (CSL)
- Single-hole Sonic Logging (SSL)
- Parallel Seismic
We have the equipment and expertise to determine which method would be most suited to your project and can provide the testing that your project requires. All testing meets the relevant ASTM standards. We can undertake testing at any location within New Zealand and the Pacific Islands.
The shear wave velocity (Vs) of the subsurface is an engineering parameter used for calculating liquefaction potential, site amplification and other engineering or pre-build requirements. Southern Geophysical Ltd can determine Vs parameters and can also provide Vs30, which feeds directly into site classifications. We can measure Vs directly using downhole shear-wave tests, or indirectly using Multi-channel Analysis of Surface Waves (MASW). The MASW provides a 2D profile of the Vs along a survey line, which can be useful for identifying changes in stratigraphy and lithology across a site.
Vibration & Sound Monitoring
Southern Geophysical Ltd undertakes a range of vibration monitoring projects for:
- Demolition activity
- Construction activity
- Heavy transportation
- Pile driving
- Dynamic compaction
- Tunnel and subway construction
- Bridge construction/response
Cross-hole Shear Wave Velocity Measurements
Southern Geophysical Ltd is able to provide the testing needed to meet MBIE requirements. The New Zealand Ministry of Business and Innovation (MBIE) Canterbury Technical Guidance Foundations, Part C (April 2015, 3a) now requires that "In soils with a higher IC value/fines content, the target CPT resistances must be achieved, or specific engineering analyses performed to demonstrate that the liquefaction potential is adequately mitigated. Alternatively, cross-hole shear wave velocity (CSV) testing can be used to assess the composite stiffness of the improvement zone. The target improvement is considered to have been met if a composite cross-hole VS profile within the improvement zone is achieved to the MBIE published criteria."
Southern Geophysical Ltd is able to provide the CSV testing needed to determine if the target composite shear wave velocities are being met for your building site.