Empowering the Indiana Bridge Inventory Database Toward Rapid Seismic Vulnerability Assessment

Abstract

With the recent identification of the Wabash Valley Seismic Zone in addition to the New Madrid Seismic Zone, Indiana’s Department of Transportation (INDOT) has become concerned with ensuring the adequate seismic performance of their bridge network. While INDOT made an effort to reduce the seismic vulnerability of newly-constructed bridges, many less recent bridges still have the potential for vulnerability. Analyzing these bridges’ seismic vulnerability is a vital task. However, developing a detailed dynamic model for every bridge in the state using information from structural drawings is rather tedious and time-consuming. In this study, we develop a simplified dynamic assessment procedure using readily-available information from INDOT’s Bridge Asset Management Program (BIAS), to rapidly identify vulnerable bridges throughout the state. Eight additional data items are recommended to be added into BIAS to support the procedure. The procedure is applied in the Excel file to create a tool, which is able to automatically implement the simplified bridge seismic analysis procedure. The simplified dynamic assessment procedure and the Excel tool enable INDOT to perform seismic vulnerability assessment and identify bridges more frequently. INDOT can prioritize these bridges for seismic retrofits and efficiently ensure the adequate seismic performance of their assets.

Enabling Rapid Large-Scale Seismic Bridge Vulnerability Assessment Through Artificial Intelligence

“…To establish an effective classification scheme for use in seismic assessment, it must be designed to identify and group bridges that have common dynamic behavior. Thus, when such a grouping is performed, the stiffness of each bridge in a given group can be estimated with a common analytical procedure ( 3 – 5 ). Bonthron et al developed such bridge substructure classes for Indiana bridges; the classes were designed to account for similarities in seismic behavior and used to rapidly determine seismic vulnerability ( 5 ).…”

“…According to the seismic vulnerability assessment strategy developed by Bonthron et al ( 3 – 5 ), Midwest bridges in the frame bents, hammerhead walls, or walls categories can be analyzed using a simplified seismic vulnerability analysis, whereas those in the “other” category require detailed analysis. Clearly, any misclassifications in this application will have varying consequences commensurate with the type of misclassification.…”

“…For example, suppose a wall substructure that might experience brittle, shear failure is labeled as a frame bent. In the subsequent analysis, this bridge will then be assessed using the wrong equations, and its prioritization for seismic retrofit may be incorrect, thereby leading to the potential failure of the bridge given the occurrence of a seismic event ( 3 , 5 ).…”

“…Although a detailed seismic evaluation is likely to be needed for unique or especially complex structures, a significant number of the bridges in low-to-moderate risk zones can be assessed and prioritized with a simplified assessment method. A simplified dynamic assessment can be conducted automatically using an asset management database and existing capacity models ( 1 – 5 ) to rapidly assess a large inventory of bridges ( 3 – 5 ). These capacity models are composed of a set of capacity thresholds that are used to rapidly determine the seismic vulnerability of bridges ( 3 – 5 ).…”

“…A simplified dynamic assessment can be conducted automatically using an asset management database and existing capacity models ( 1 – 5 ) to rapidly assess a large inventory of bridges ( 3 – 5 ). These capacity models are composed of a set of capacity thresholds that are used to rapidly determine the seismic vulnerability of bridges ( 3 – 5 ). When used proactively, such an analysis can provide actionable information to prioritize seismic retrofits for preemptively reducing vulnerability for critical routes or in key regions.…”