Know what the ground will carry.
Geotechnical investigations and soil testing across Christchurch and Canterbury, establishing ground conditions, soil bearing capacity and foundation requirements through site investigation, testing and engineering assessment.
Testing turns a guess into a number.
Ground conditions can change significantly from one property to the next. Site-specific geotechnical investigation establishes the soil profile, bearing capacity, groundwater conditions and potential ground hazards rather than relying on assumptions. The results provide the engineering parameters needed for the geotechnical report and foundation design, so the foundation is designed for the ground that is actually there.
Geotechnical EngineeringThe tests we run.
From shallow soil testing to deep ground investigation, including hand augers, Dynamic Scala Penetrometer testing, shear vane, CPTs, machine boreholes and laboratory testing, selected to suit the site, ground conditions and proposed development.
Hand augers
Shallow sampling to 3.0m, with each layer described and logged as the auger comes up.
Shear vane
The undrained shear strength of cohesive soils, measured in place rather than estimated from a chart.
Scala Penetrometer
A fast index of shallow ground strength to 3.0m, taken at close spacing so a soft pocket cannot hide between holes.
Cone Penetrometer Test
CPT pushed to a minimum of 15m below ground level, giving a continuous strength profile rather than samples at intervals.
Machine borehole
Where CPT cannot be undertaken, drilled and sampled deeper, with the recovered material logged the whole way down.
Groundwater observation
The water level recorded in the holes, because where the water sits changes what the ground above it will do.
Testing across the footprint
Positions set out where the building will actually sit, not where the ground is easiest to get at.
How it runs.
From site investigation and soil testing through to engineering analysis, geotechnical recommendations and the design parameters your foundation needs.
- 01
Visit and set out
We set the test positions off your plans before a rig is booked, and check what the machine can physically reach while we are there. Testing commences within two to three weeks of confirmation.
- 02
Shallow testing
The shallow holes go down first, so the ground near the surface is described and logged before anything deeper is pushed. What the first few metres return often decides how much deeper the rest has to go.
- 03
Deep testing
Where the loads or the ground call for it, the testing carries on well below the shallow limit, on the same visit. One mobilisation covers both, so nobody pays to bring a rig back a second time.
- 04
Log the ground
Investigation locations are recorded and the ground profile is logged in the field as testing progresses, documenting soil type, depth, groundwater conditions and test results to build an accurate picture of the ground beneath the site.
- 05
Classify and report
Field and laboratory results are reviewed and interpreted to establish the ground profile, soil parameters and relevant geotechnical hazards. The findings are brought together in a clear geotechnical report with foundation recommendations and the design parameters needed to move the project forward.
Reading the ground.
Ground investigation builds a picture of the site from the surface down, identifying each soil layer, its consistency or density, groundwater conditions and measured test response. What matters is not just the soil at foundation level, but the entire profile beneath it. Weak or compressible layers at depth can influence bearing capacity, settlement, liquefaction and ultimately the foundation solution.
What the testing tells you.
The ground profile, bearing capacity, settlement potential, groundwater conditions and geotechnical hazards, translated into practical design parameters and foundation recommendations.
Soil classification
Identifying the soil types, layer thicknesses and engineering characteristics of the ground, from topsoil and fill through to the natural soils that influence bearing capacity, settlement and foundation design.
Bearing capacity
Establishing the soil bearing capacity at foundation level, providing the geotechnical design parameter needed to size footings and select an appropriate foundation system.
Site technical category
Assessing whether the site is consistent with TC1, TC2 or TC3 land performance, considering liquefaction vulnerability and expected ground deformation to inform the appropriate foundation solution.
TC1 to TC3 explainedLiquefaction potential
Assessing liquefaction susceptibility and triggering using CPT and other site investigation data, including the likely depth and extent of liquefied layers, liquefaction-induced settlement and ground deformation, to determine the implications for foundation design and site performance.
TC1 to TC3 explainedGroundwater
Establishing groundwater conditions and the design water table for foundation design, excavation and dewatering, drainage, settlement and liquefaction assessment, including consideration of seasonal groundwater variation where relevant.
Soil logs and a site plan
A clear record of what was encountered and where, with investigation locations shown on the site plan and soil logs documenting the ground profile, test results and groundwater observations that support the geotechnical assessment.
Further testing, where it is needed
Where the initial investigation identifies uncertainty or more complex ground conditions, we recommend the appropriate next step, whether deeper investigation, CPT or borehole testing, laboratory testing, groundwater monitoring, liquefaction assessment or detailed slope stability analysis.
What a geotechnical report contains
What soil testing looks like.
From hand augers and Scala testing to CPTs, machine boreholes and earthworks inspections, see how we investigate the ground, verify site conditions and provide the engineering information behind the design.
Assume the ground, pay for the assumption.
Skip the investigation and the foundation is designed around assumptions. If those assumptions are wrong, the cost can appear later as unexpected ground conditions, settlement, cracking or remedial work. Site-specific geotechnical testing reduces that uncertainty early, before the foundation is designed and while changes are still relatively simple and inexpensive.
Test the ground before you buy or build.
Whether you are considering buying a section or preparing to build, understanding the ground early can identify geotechnical constraints before they become costly surprises. Send us the site address and proposed plans, and we can recommend the appropriate level of investigation for the site.