Stay Cable Multi-tube Saddles, Design and Testing

Abstract

Saddle systems for stay cables are at the moment one of the preferred solutions in the field of cable stayed bridge design across the world, and this trend seems to increase day by day. The most advanced systems currently available for parallel strand stay cable systems are multi-tube friction saddles, where each single strand runs into an individual pipe and the stay cable differential force is transferred by friction. The structural behaviour of a saddle device is a very complex topic involving several mutually dependent aspects. The development and validation of saddle systems is usually performed in the frame of the design assisted by testing. Full-scale tests have been carried out at the Structural Engineering Laboratory of Politecnico of Milan taking into account current developments of International Recommendations, such as FIB Bulletin 30 and PTI DC 45.1-12, with the aim of characterizing friction, fatigue and static performances of saddles.