Study of termination criteria and acceptance criteria for long driven piles including jack piles and development of a comprehensive piled foundation database for Hong Kong soils (PI: Prof. Zhang LM; Co-I: Prof. Ng CWW and Prof. Tang WH; MPhil students: Messrs. Lawrence Shek and Chan F., Miss Agnes Ng) 

Control of pile driving in Hong Kong is currently based on Hiley’s formula that is commonly considered inaccurate.  The incompetence of the formula has resulted in serious pile foundation problems.  A step forward would be the use of stress wave based methods or energy methods for substituting Hiley’s formula.  However, experience with the wave methods and energy methods for long piles in weathered and fill materials is still very limited.  The objectives of this research project are to compile a comprehensive database for driven piles in Hong Kong soils and to critically evaluate and propose termination and acceptance criteria for driven piles and jacked piles.  Wave equation parameters for driving of long piles in Hong Kong soils will be investigated to improve the reliability of stress wave based methods.  Advanced centrifuge modelling and numerical modelling will also be conducted to clearly understand the fundamental behaviour of jacked piles and driven piles. Based on the pile database and results from centrifuge and numerical modelling, suitable termination and acceptance criteria for driven piles and jacked piles will be suggested. The results from this research will enhance the safety of public housing developments and reduce the costs of pile foundations.