In-situ testing
Plate load and pile load tests, dynamic probing, trial pits, infiltration, electrical resistivity and thermal conductivity, measured where the structure will stand.
Some answers have to be measured in place. We test bearing, settlement, drainage, and the electrical and thermal properties of the ground on site, with calibrated jacks, load cells and data loggers.
Plate load tests
A 300 mm plate is loaded by hydraulic jack against an excavator reaction, in stages from 75 kPa to 750 kPa. Each stage is held until settlement slows to 0.2 mm per minute, read to 0.01 mm. From the results we derive the modulus of subgrade reaction, corrected for plate size following IS 9214.
Pile load tests
Static load tests on helical piles in compression, uplift and lateral loading. Load is applied in three cycles, to 50, 100 and 200 per cent of the design load, with 15-minute holds and 60-minute holds at peak load. Compression tests follow ASTM D1143.
Dynamic probing
Dynamic cone penetrometer (DCP), light dynamic probe (Mackintosh) and a motorised probe rig. Probing is quick and cheap, fills the gaps between boreholes, and is correlated to SPT N values. It suits roads, drainage and light structures.
Trial pits, density and infiltration
- Trial pits to see the ground profile and take bulk samples.
- Field density and in-situ moisture content.
- Infiltration and percolation tests for drainage, soakaway and stormwater design.
Electrical resistivity and thermal conductivity
Ground resistivity for earthing design, and thermal conductivity for buried cables. Both are routinely needed on solar, substation and power projects.
Deliverables
- Load-settlement curves and test records
- Modulus of subgrade reaction
- Probe and trial pit logs
- Infiltration and percolation rates
- Resistivity and thermal conductivity results
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Tell us about your site and we will propose the right investigation, testing, survey and reporting for your design and construction stage.