Performance based earthquake engineering approach applied to bridges in a road network

Abstract

The most recent developments in earthquake engineering design are based on the concept of prescribed performance levels, rather than the traditional prescriptive approaches. A relatively well-known software tool for conducting PBEE studies for bridge-ground systems (BridgePBEE), which is based on three-dimensional (3D) finite element model analyses carried out in OpenSees, considering a simplified soil-structure interaction macro element, has been recently applied to a limited number of individual bridge structures. This study aims to apply a Performance-Based Earthquake Engineering (PBEE) methodology to the seismic assessment of an existing road network, in which the nodes correspond to bridges, rather than to a single structural configuration, using BridgePBEE to study the response of different real bridges. Such versatile Finite-Element (FE) environment provided the possibility of processing detailed information on effective damage, safety and economic assessment. In addition, by definition of PBEE, informed decisions of the evolution of seismic losses in terms of cost and time repair quantities were derived at different Peak Ground Acceleration (PGA) levels. Nonlinear dynamic analyses were then run by using properly selected seismic records as input, by means of the conditional spectrum method applied to the seismic hazard outputs for the considered target site, using peak ground acceleration as reference intensity measure. The conclusions provide performance considerations of the investigated population of bridges in terms of repair costs and time, deriving relevant considerations for design procedures.