Resumen
This paper describes the development of the project designared as Line 4 of the Santiago's subway, which includes the construction of a new railway fine with 32.4 kilometers of longitvde, consisting of underground, surface and elevared tracks in the city of Santiago, Chile. The design of the viaduct has been based on the intensive use of interlocking prefabricared structures (segmenta/ bridges), with the purpose of minimizing the impact- regarding time and space - that this type of project usual/y generares on che roadways surrounding its layout. In addition, this project has achieved an architectural design of slender forms and soft and rounded fines, in harmony with che surroundings. The design of che viaduct ís characterized by a "U" type superstructure, which is built with interlocking prefabricated segments (segmental bridges). This method is quite usual in developed countries but is applied for the first time on a viaduct in Chile. Another important issue addressed in this project has been the seismic analysis of the area. To perform this study, a design spectrum was created based on four seismic movements that affected Santiago in the past.