Seismic Vulnerability of the Italian Roadway Bridge Stock

Abstract

This study focuses on the evaluation of the seismic vulnerability of the Italian roadway bridge stock, within the framework of a Civil Protection sponsored project. A comprehensive database of existing bridges (17,000 bridges with different level of knowledge) was implemented. At the core of the study stands a procedure for automatically carrying out state-of-the-art analytical evaluation of fragility curves for two performance levels—damage and collapse—on an individual bridge basis. A WebGIS was developed to handle data and results. The main outputs are maps of bridge seismic risk (from the fragilities and the hazard maps) at the national level and real-time scenario damage-probability maps (from the fragilities and the scenario shake maps). In the latter case, the WebGIS also performs network analysis to identify routes to be followed by rescue teams. Consistency of the fragility derivation over the entire bridge stock is regarded as a major advantage of the adopted approach.

Seismic fragility assessment of integral precast multi-span bridges in areas of moderate seismicity

“…in the US (Nielson 2005), Italy (Borzi et al 2015), Greece (Moschonas et al 2009), Turkey (Avşar et al 2011) and Algeria (Kibboua et al 2014), but to the best of the authors' knowledge, there is no such study on highway bridges in a moderate seismic zone of Europe. The results of the mentioned studies can be used to presume the seismic behavior of PMG bridges in moderate seismic zones; however, there are several reasons why they cannot be adapted directly: (1) in most low or moderate seismic zones, seismic design of bridges did not exist or underestimated the seismic effects; (2) the higher seismicity of the mentioned countries in Europe results in different design concepts and thus structural characteristics as well as details; (3) Hungarian PMGs are dominantly integrated continuous bridges, while simply supported versions are equally preferred in the mentioned regions; (4) differences in the relevant input parameters (e.g.…”

Simulated Design Procedure for an Improved Seismic Vulnerability Assessment of Existing Rc Bridges

“…Collecting a sufficient level of knowledge of the structure is indeed a preliminary and fundamental step in the seismic response analysis [1] [2]. The required information should be gathered through the review of the executive design documentation, when available, in combination with in-situ surveys and material tests.…”

“…Then the bearing devices between the super-and sub-structure are assumed to transfer the entire lateral load to the substructure, including the case of merely frictional bearing capacity [2] [28]. This is considered to be consistent with the requirement for structure serviceability prescribed for the design level of loads.…”

Seismic Retrofit Decision-Making of Bridges Based on Life-Cycle Cost Criteria

“…In order to be consistent with recent studies on bridge infrastructures in Italy (see [12,25]), two limit states (LS) or performance levels are considered: damage Limit State and collapse Limit State. The time-dependent limit state probabilities are evaluated based on both limit states.…”

“…It is primarily introduced in [28], and further utilized in [9,29]. It is recently used as a proper decision variable for assessing the existing bridge infrastructures in Italy [25,30]. Since there are various SD's for a given limit state, Y LS is capable of finding the critical situation while relating the structural behaviour at the component level to its global performance.…”