By J Delapierr, Pieux Franki and C H Dufour, Traction et Electricites
This paper was first publsihed in GE’s March 1980 issue
The Doel III nuclear power station, near Antwerp, is founded on Franki piles which have to resist large horizontal shears at the ground surface. Because of the nature of this type of structure, it is important to predict with accuracy the lateral load behaviour of the piles. This type of analysis is not yet widely undertaken.
The behaviour of piles under the action of lateral loads depends on the stiffnesses of both the pile and soil and how these factors vary along the pile. Near the surface the passive resistance of the soil can become the critical factor.
The consulting engineers, Traction et Electricites, decided to carry out a fullscale horizontal loading test at the power station site. After consultation with Professor De Beer of the State University of Ghent and Professor Lousberg of the Universite Catholique de Louvain, the test was carried out in December 1975 and was taken all the way to failure. The test was therefore a joint collaboration between the consulting engineers, the Belgian Geotechnical Institute (Prof. De Beer), the Universittg Catholique de Louvain (Prof. Lousberg) and Pieux Franki.
By analysing this test it has been possible to check a relatively simple semiempirical method of prediction, This method has proved reasonably accurate in predicting both the moments and deflections of a single pile loaded at the top.