: Massive soil displacement from multiple close-proximity piles often forces previously installed piles upward. Structural engineers are required to run routine leveling checks to identify heaved piles, which must be re-jacked to full refusal if displacement occurs.
For the resident engineer, the key takeaway is this: For the contractor, invest in continuous logging systems and real-time heave monitoring. For the designer, remember the setup phenomenon – a pile that stops at 5,000 kN today may deliver 7,000 kN in a month.
The Geotechnical Society of Singapore (GeoSS) provides specific guidelines for the to manage ground displacement and protect adjacent structures , which is critical in Singapore's dense urban environment. Key Good Practice Guidelines (GeoSS) For the designer, remember the setup phenomenon –
For the full GEOSS document (2021 edition) and the latest addendum on jacked piles, visit the Singapore Society for Geotechnical Engineering (SSGE) portal.
The stability of the jacking machine must be verified, especially on soft ground. Specialist builders must maintain high-capacity rigs; for example, G3 category specialists require rigs with a minimum 400-ton counterweight . The stability of the jacking machine must be
Given the massive weight of jacking machines, the working platform must be high-quality, with strict requirements for compaction and site drainage. Verticality:
In Singapore, the design and installation of jacked piles are regulated under the . Verticality: In Singapore
A pile is generally considered "set" if the downward movement does not exceed 10 mm (some guidelines specify 5 mm ) during a holding time of at least 30 seconds .
