Geoss Good Practice For Installation Of Jacked Foundation Piles In Singapore Link -

| Parameter | Good Practice Limit | GEOSS Trigger (Action Required) | |-----------|--------------------|----------------------------------| | Jacking rate | 0.5 – 1.5 m/min | >2 m/min (reduce rate, check hydraulic oil temp) | | Max jacking force | ≤ 80% of pile structural capacity | >85% – stop jacking, assess toe damage | | Heave of adjacent ground | < 10 mm | 10–25 mm – reduce jacking rate; >25 mm – stop, grout relief holes | | Pile verticality | < 0.5% deviation | >1% – de-jack, re-align; >2% – abandon pile | | Hydraulic pressure spike | < 15% of steady pressure | >15% – inspect pile head & shoe |

✅ Jacking frame calibrated (valid < 3 months)
✅ Heave markers installed on adjacent structures (max spacing 15 m)
✅ Real-time force & displacement logger active
✅ Operator has valid BCA piling supervisor card
✅ Contingency grout pump on site (within 10 m of jacking rig)
✅ Rainfall in last 24 hrs < 20 mm (to avoid soft top clay) | Parameter | Good Practice Limit | GEOSS

| Problem | GEOSS Recommended Action | |---------|---------------------------| | Refusal before design depth | Check for boulder; use pre-augering or vibro-displacement. | | Heave of adjacent ground | Reduce jacking rate, install relief holes, or sequence piles from center outward. | | Pile cracking (concrete) | Reduce jacking force; check alignment; use steel shoes. | | Excessive jacking force | Verify soil parameters; consider reducing pile spacing or increasing pile size. | install relief holes