Pile bearing capacity of the new bridge over Zambezi River (Mozambique): predictions and performance of static load test results

Abstract

The evaluation of pile bearing capacity is dependent on the interpretation of the pile head load-settlement curve and the determination of the shaft and toe resistances in careful and well instrumented tests. It is then possible to calibrate design methods with load transfer curves at different depths for progressive loading levels. In the New Zambezi Bridge (Caia Chimuara, Mozambique) deep foundations have been designed taking into consideration different methodologies: methods based directly in SPT data (Reese & ONeill) and methods based in CPT data (Bustamante & Frank, 1999), giving rise to some scatter in final results. For the complete and trustful solution, static load tests on some piles were executed using the Osterberg test method, in order to obtain a simple way to evaluate shaft load transfer and define the applicability of each empirical methodology. Results of this comparative analysis are proposed and some suggestions are presented for regional practice.