Non-linear 3D seismic analysis of a RC bridge and retrofit alternatives with passive protective systems

NANCLARES, GERMÁN; AMBROSINI, DANIEL; CURADELLI, OSCAR

Journal of Physics: Conference Series

IOP Publishing

Año: 2024

1742-6596

In this paper a proposal of a partially restrained seismic isolation (PRSI) system ispresented for the retrofit of existing continuous girder RC bridges. A pure-friction system is usedwith auto centring force provided by the stiffness of the deck and the frictional forces generatedat the contact acting as an energy dissipation mechanism. The proposal has the advantage thatthe very small height of the system allows its application to existing bridges. In order to studythe proposed system, the dynamic response until collapse of an existing bridge subjected toseismic accelerations is assessed through a detailed 3D nonlinear numerical model. An explicitintegration scheme is employed that avoids numerical convergence drawbacks due to strengthand stiffness degradation of concrete structures. The numerical model identifies the collapsemechanisms, such as the development of cracks in the concrete elements. Two retrofit systemsare studied: a) steel jacketing reinforcement and b) PRSI proposal. The efficiency of eachalternative is evaluated in terms of displacements and shear forces.