High capacity bored piles in soft volcanic rock—experiences based on single- and multi-level tests

For the improvement of the infrastructure in the Canal Zone of Panama in Central America it was decided to construct a second bridge crossing the Panama Canal. The bridge with a total length of 1,050 m was designed as cable stayed bridge crossing the 100 m deep Gaillard trench of the Canal (Fig. 1). As the bridge is just the second link over the Canal it will be of special relevance for the connection between North and South America (‘Interamerican Highway’). The foundation design for the pylons and piers of the bridge was influenced by the very heterogeneous subsoil conditions predominated by soft rocks of volcanic debris (McCullough 1977, Stewart 1984).