Installation Of Jacked Foundation Piles In Singapore: Geoss Good Practice For

After reaching the target force, the pressure is released and reapplied without pause.

: Necessary tests (e.g., sonic or PDA) must be conducted to prove the quality and durability of the installed piles. Risk Management

[Kallang Formation] --> Soft marine clays (Risk of pile drifting & heave) [Old Alluvium] --> Dense silty sands (High jacking resistance) [Jurong Formation] --> Highly weathered sedimentary rock (Unpredictable refusal) 1. Kallang Formation

Good Practice for Installation of Jacked Foundation Piles in Singapore

: The bearing capacity of the ground supporting the massive Kentledge blocks must be analyzed using representative soil investigation data to prevent settlement or failure. Typical Applications in Singapore Common Sizes After reaching the target force, the pressure is

Ground supervisors, technical managers, and piling engineers must successfully undergo formal training to register with the IES/GeoSS Piling Personnel Registry . This certification ensures that on-site personnel can interpret real-time hydraulic pressures and identify underground anomalies immediately. 2. Key Geotechnical Challenges in Singapore Soil Formations

The first pile segment must be pitched with absolute vertical precision. GEOSS recommendations mandate monitoring verticality using two orthogonal total stations or electronic spirit levels throughout the process. The vertical deviation must not exceed 1 in 100. Step 3: Continuous Jacking

| Site Condition | Recommended Sequence | |----------------|----------------------| | Single isolated pile | No special sequence. | | Group of piles (≤9) | Center-outwards or spiral. | | Long pile rows (e.g., for retaining walls) | Staggered, with pre-drilled pilot holes (50–70% pile diameter) to reduce displacement. | | Adjacent to MRT / existing building | Install “sacrificial” or “guard” piles first, then inner piles. Use extremely low jacking rates (<5 mm/s). |

For large pile groups, jacking should proceed from the inside out or in a consistent direction (e.g., left to right) to manage ground displacement. Kallang Formation Good Practice for Installation of Jacked

Protects adjacent aging structures and sensitive utilities from settlement.

Re-jack all piles in a group after 24–48 hours of set-up to confirm no loss of capacity due to heave.

Eliminates the disposal costs and environmental hazards of drilling mud. Singapore’s Geological Challenges Alignment & Verticality: Unlike driven piles

For steel joints or precast pile end-plates, certified welders must execute full-penetration butt welds.

For larger pile groups, it is recommended to jack from the inside out or in a consistent direction (e.g., left to right) to manage ground displacement and potential heave. Alignment & Verticality:

Unlike driven piles, jacked piles require a controlled, steady penetration rate.