Computerised processing of ground investigation data and use in predicting the load-settlement behaviour of piled foundations

Abstract

A new computer program “PILESET” is developed for use in predicting the bearing capacity and load-settlement behaviour of axially loaded single piles. The program can analyse almost any soil profile and accommodates (a) displacement piles (b) replacement (c) friction piles, (d) end-bearing piles, (e) under-reamed piles and (f) partially sleeved piles. A variety of soil input data can be used, including: (i) standard penetration tests, (ii) cone/piezo-cone tests, (iii) pressure-meter tests and (iv) laboratory tests. The above data types can be combined, if desired, for pile analysis by PILESET. The program calculates the shaft and base capacities of a pile based on 23 methods published in design guides in over 10 European countries. PILESET also predicts the pile load-settlement curve using five published methods, which include two modified load transfer (t-z) approaches formulated by the author. To demonstrate the capabilities of the program, analysis is carried out for case study involving seven full-scale screw piles formed in sand and tested to failure. In each case, the load-settlement curve computed using the author’s modified method in PILESET is found to be in excellent agreement with the actual pile test results.

Keywords:

• pile foundations
• software development
• mathematical modelling

Acknowledgements

Special appreciation is due to the Belgian Building Research Institute (BBRI) for permitting the use of their field test data and for inviting the author to participate at an international prediction event. Other thanks are due to the University of Glamorgan for allowing the author to carry out work in industry and for providing various facilities.

Additional information

Funding

The Royal Society, UK, is thanked for awarding a generous Fellowship grant over two years. The database of pile tests described in this paper was compiled from the BBRI research programme: Soil displacement screw piles-calibration of calculation methods and automation of the static load test procedure (supported by the Belgian Federal Ministry of Economical Affairs, Convention CC-CI-756).