The pile alignment must never be adjusted by external lateral force once the jacking process has commenced. Forcing a tilted pile straight introduces massive, uncalculated bending moments that can lead to structural overstressing or structural failure under working loads.
The project manager noted: "Following the GEOSS link to detailed procedure saved us from a potential S$2 million claim for tunnel damage."
The adoption of good practice guidelines for the installation of jacked foundation piles in Singapore offers several benefits, including: The pile alignment must never be adjusted by
: Historically limited to low-capacity, small-diameter segments, the industry now relies heavily on larger structural units, such as 600 mm diameter high-strength precast concrete spun piles . Installation Control and Refusal Criteria The ultimate geotechnical capacity of a jacked pile ( Pucap P sub u ) relates tightly to the maximum jacking force applied ( Pjcap P sub j ). GeoSS technical studies indicate that Pucap P sub u typically ranges between 0.8 Pjcap P sub j Pjcap P sub j
: Jack until refusal, release the force to zero, and re-apply without pause. This measures the downward movement, known as the "set". Standard Acceptance Standard Acceptance The design of jacked foundation piles
The design of jacked foundation piles should be based on the site investigation report and relevant design codes, such as the Singapore National Annex to Eurocode 7. The pile specifications should include details on the pile type, diameter, length, and material properties. The design should also consider factors such as pile capacity, settlement, and soil-structure interaction.
: Specialist builders must maintain a regular maintenance regime with daily, monthly, and quarterly checklists to ensure rigs remain in good working condition. Pile Heave and soil-structure interaction.
GEOSS has been instrumental in publishing authoritative guidelines that shape piling practices, including:
[ Hydraulic Jack Cylinder ] <-- Smaller contact area │ │ ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ <-- High localized concentration of force =========================== [ Reinforced Pile Head ] <-- Requires additional structural confinement [ ] Geotechnical Capacity Formulae
High-capacity rigs impose heavy direct bearing pressures beneath their sleeper platforms, often reaching up to 200 kPa . Site platforms must be reinforced to support this weight without localized slope or ground failures. 3. GeoSS Core Principles of Installation Practice