Very high loads
Capacity in the hundreds of tonnes is achievable without a large surface reaction system.
Foundation Testing
Bi-directional Load Test
A pile load test that loads the pile against itself using an embedded jack, with no surface reaction system.
Overview
A hydraulic jack cell is placed within the pile; it pushes the upper shaft up and the lower shaft and base down so the two portions react against each other. High capacities can be tested without reaction piles or kentledge.
A bi-directional test places a sacrificial jack (load cell) inside the pile and pushes the shaft up and the base down against each other. The pile provides its own reaction, so very large loads can be tested without heavy frames or kentledge at the surface.
- Embedded jack cell within the pile
- Separates shaft and base resistance
- No surface reaction frame required
- Suited to high-capacity and hard-to-access piles
Key Benefits
Works where access is limited
Suited to river, marine, congested and elevated sites.
Separate shaft and base curves
Each resistance is measured directly.
Safer, tidier site
Less heavy plant and kentledge to handle.
Where It Is Used
- River and marine piles
- Very high-capacity bored piles
- Constricted urban sites
- Piles that are hard to reach from the surface
How We Work
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1
Position the jack
Locate the load cell at the level that balances shaft and base resistance.
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2
Cast into the pile
Install the assembly with the reinforcement cage and concrete the pile.
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3
Pressurise the cell
Pump in stages, recording upward and downward movement.
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4
Construct the equivalent curve
Combine results into an equivalent pile-head load-settlement curve.
What You Receive
- Upward and downward load-movement curves
- Equivalent top-loaded curve
- Shaft and base capacity values
- Test report
Frequently Asked Questions
Is the jack recovered?
The cell stays in the pile and is normally grouted after the test.
Can it be used on any pile?
It must be planned before the pile is constructed, since the cell is cast into it.
Have an infrastructure testing or monitoring requirement?
Tell us about your project — our engineering team will follow up on scope, instrumentation and approach.