Civil Engineering Association

This publication gives guidance on the selection, design and installation of steel H-piles and UC section plunge columns for foundations to all types of structure. Current practice and experience in this field are presented, discussed and recommendations given. The characteristics and advantages of steel bearing piles in construction are described in order to assist in the primary process of selection of the correct pile type for any given site and soil conditions. Load transfer mechanisms are described and limit state design methods applied in line with the new Eurocodes. The sections on design include axial and lateral load resistance prediction methods, combined loading effects on retaining walls and pile group analysis. Up-to-date pile driving analysis is presented as a basis for planning efficient installation and as an aid to design. Practical aspects of test loading, installation tolerances and connection details are covered.
It is noted that excessive conservatism has been found in current practice and this results in unnecessary overdesign. Currently used specifications for load testing piles only up to 1.5 × working load, are insufficient to reach the ultimate pile resistance and the whole object of the new limit state design (LSD) procedures has been denied. This problem has been compounded by making unrealistically low design assumptions on the soil parameters in pile resistance prediction methods. This publication adopts LSD using the new Eurocodes and suggests more reliance be placed on static and dynamic load test methods to establish ultimate capacity to permit more economic steel pile design.