Assessment of load carrying capacity of driven piles - a practical approach

摘要

In the last decade, Hong Kong has seen many advancements in the technology of pile installation and driving. Examples are the introduction of hydraulic hammers, use of plastic cushions and the introduction of high capacity, Grade 55C steel, H-piles. The use of hydraulic hammers has though created some difficulty in the assessment of pile capacity. Questions are often asked as to whether the Hiley Formula remains appropriate, albeit commonly used in Hong Kong for many years adopting coefficients developed in the early fifties. This paper presents different methods of pile capacity assessment with a view to recommending a practical approach applicable to all driven piles. The results show that CAPWAP (CAse Pile Wave Analysis Program) analysis is a fairly accurate method for capacity prediction. And the results also show that, provided appropriate parameters are used, the Hiley Formula remains applicable with good accuracy when hydraulic hammers are used.