: Areas with marine clay require designers to account for negative skin friction (downdrag) caused by consolidating soil layers. Bentonite or polymer slurries are often required to maintain borehole stability.
Guidelines typically require boreholes every 15 to 30 meters for high-rise structures.
The Joint BCA/IES/ACES/GeoSS Circular 2016 established mandatory requirements for ground investigation, load tests, and quality control tests for foundations of: (1) buildings of ten storeys or more; and (2) buildings of five to nine storeys with a footprint larger than 100 m².
The 2016 circular introduced , aligning with Eurocode and superseding earlier standards. For buildings of five storeys or more with a footprint exceeding 100 m², mandatory ground investigation protocols include:
In 2025, BCA, IES, ACES, and GeoSS jointly issued new guidelines for bored piles in limestone areas. These guidelines bring together industry best practices into a single, . Key elements include:
The GEOSS framework consistently emphasizes . For developments in challenging ground conditions, particularly those with potential limestone cavities or slump zones, Developers, Builders, and QPs must ensure these assessments are properly executed and their findings incorporated into the design and construction methodology.
The GeoSS guidelines also serve as a model for other regions facing similar geotechnical challenges. Western Singapore’s karstic limestone formations bear close resemblance to those in Qatar, Malaysia, and other parts of Southeast Asia, where hidden cavities pose analogous risks. The risk‑based, collaborative, and locally‑calibrated approach pioneered by GeoSS offers a transferable template for developing local practices worldwide.
: Are you focusing on a specific geography (e.g., Southeast Asia, Northern Europe)?
In historic cities like Rome or Mexico City, you are not driving piles into "virgin soil." You are driving through 2,000 years of demolition debris, old wells, and forgotten timber foundations.
The Geotechnical Society of Singapore (GeoSS) provides established guidelines for pile foundation design and construction, aligning local practices with Eurocode 7 (SS EN 1997-1). These standards cover performance-based design for bored piles, load testing with kentledge blocks, and specific procedures for jacked piles to ensure structural stability. For the full guidelines, visit GeoSS . GeoSS Guidelines
: If a pile reaches the termination criterion but is significantly shorter than the design depth, a designer must formally assess if it can be terminated. Load Testing (Kentledge Method) Guidelines detail the safe setup for load tests using the Kentledge method , including block arrangements and stability checks.
The Geotechnical Society of Singapore (GeoSS) is a professional organization dedicated to advancing the practice of geotechnical engineering in Singapore. It serves as a key platform for knowledge exchange, technical training, and the development of industry guidelines. GeoSS works closely with government agencies—most notably the Building and Construction Authority (BCA)—as well as with other professional bodies such as the Institution of Engineers Singapore (IES), the Association of Consulting Engineers Singapore (ACES), and the Singapore Contractors Association Ltd (SCAL).
