Quality and verification
Ground engineering work is accepted on how the ground performs afterwards. Each job is planned so that the requirement, the work done and the proof of the result can each be traced.
Three records, kept separate
Each job is documented in three records that are often mixed together. Here they are kept separate.
What is required
The performance the structure needs, such as bearing pressure, settlement limits or retained height, and the acceptance criteria that follow from it.
What was done
The parameters applied at every point, pile or panel, recorded as the work proceeds.
What was proven
Independent tests after the work, compared with the criteria agreed at the start.
Before work starts
- The site investigation is reviewed against the method proposed. Gaps are raised before mobilisation.
- The performance requirement is written as measurable acceptance criteria and agreed with the consultant.
- A method statement sets out the equipment, sequence, controls and tests.
- An inspection and test plan lists who checks what, when, and against which criterion.
Trial and calibration
Ground response depends on soil type, density, fines content and groundwater, all of which vary. A trial area, or preliminary test piles for piling work, replaces assumptions with measurements before full production starts.
- Baseline testing in the trial area.
- Treatment or installation with the proposed parameters, with every parameter recorded.
- Testing after treatment, compared with the baseline and the acceptance criteria.
- A trial report that fixes the production parameters, agreed with the consultant.
Control during production
- Setting out is surveyed, and every treatment point, pile or panel has a unique reference.
- The agreed parameters are recorded for each one, from rig instruments where they are fitted.
- Records are reviewed daily, and anything outside the agreed range is reported and resolved at that point.
- If the ground differs from the investigation, work in that area stops until the parameters are reviewed.
Acceptance testing
The test type, number and locations are agreed with the consultant for each project. Test locations include the positions where improvement is expected to be lowest.
Where a result does not meet the criteria, the response is agreed with the consultant: further testing, additional treatment or a design review.
What is handed over
- Method statement and inspection and test plan.
- Trial report with the agreed production parameters.
- As-built drawings and production records for every point, pile or panel.
- Calibration certificates for test and monitoring equipment.
- Test results before and after, with interpretation against the acceptance criteria.
- A final report that ties the three records together.
Need to see how a method would be verified on your site?
Share the site investigation report and the performance requirement.