A Risk-Based Methodology for Assessing the Seismic Performance of Highway Systems (2000-2001)

Craig E. Taylor, President, Natural Hazards Management Inc. James E. Moore III, Associate Professor, Departments of Civil Engineering and Public Policy and Management, University of Southern California Sungbin Cho, Research Associate, School of Policy, Planning, and Development, University of Southern California Jon S. Walton, Vice President, MacFarland Walton Enterprises Stuart D. Werner, Principal, Seismic Systems and Engineering Consultants Past experience has shown that effects of earthquake damage to highway components (e.g., bridges, roadways, tunnels, etc.) may not only include life safety risks and post-earthquake costs for repair of the components. Rather, such damage can also disrupt traffic flows and this, in turn, can impact the economic recovery of the region as well as postearthquake emergency response and reconstruction operations. Furthermore, the extent of these impacts will depend not only on the seismic response characteristics of the individual components, but also on the characteristics of the highway system that contains these components. System characteristics that will affect post-earthquake traffic flows include: (a) the highway network configuration; (b) locations, redundancies, and traffic capacities and volumes of the system's links between key origins and destinations; and (c) component locations within these links. From this, it is evident that earthquake damage to certain components (e.g., those along important and non-redundant links within the system) will have a greater impact on the system performance (e.g., post-earthquake traffic flows) than will other components. Unfortunately, such system issues are typically ignored when specifying seismic performance requirements and design/strengthening criteria for new and existing components; i.e., each component is usually treated as an individual entity only, without regard to how its damage may impact highway system perResearch Objectives