Geology topics

Kuo-wan Lin

Publications and source records attributed to Kuo-wan Lin.

8 recordsLinked to original sources

USGS2022

Assessing direct and indirect long-term economic impacts from earthquakes to the U.S. National Bridge Inventory

Using the 2018 National Seismic Hazard Model and the 2018 National Bridge Inventory, an annualized earthquake loss (AEL) study was conducted for approximately 610,000 bridges in the conterminous United States, quantifying both direct and indirect economic losses. The typical AEL framework has been augmented with new replacement unit cost data and bridge-specific parameters for modifying default fragility curves. Earthquake hazard is defined using spectral acceleration hazard curves that account for location-specific soil conditions. Hazard is integrated with bridge-specific fragility curves to compute annual probabilities of exceeding various damage states. Further, economic loss for each bridge was estimated using the repair costs associated with specific damage states and indirect costs incurred from downtimes. Quantitative assessments of seismic risk, especially those that account for downtime-related impacts, enable us to illustrate the distribution of risk with respect to geographic region, era of construction, or type of bridge.

conterminous United States↗

USGS2022

Critical ShakeCast lifeline users and their response protocols

ShakeCast is a US Geological Survey (USGS) software application that automatically retrieves ShakeMap shaking estimates and performs analyses using fragility functions for buildings and lifelines. The ShakeCast system aims to identify which facilities or lifeline segments are most likely impacted by an earthquake—and thus which ones should be prioritized for inspection and response—and sends notifications to responders in the minutes after an event. By focusing inspection efforts on the most damage-susceptible facilities in the severely shaken areas, ShakeCast can improve critical lifeline inspection prioritization and reduce response time in the aftermath of a significant earthquake. Overviews and technical specifications of the ShakeCast system and software have been presented at earlier conferences; here we discuss ShakeCast users and their response protocols to provide further insight into the use of the ShakeCast system. We focus on case histories of ShakeCast users who are responsible for monitoring and response for critical infrastructure. We emphasize the inventory, fragility, and notification issues pertinent to these users, their efforts in developing protocols for post-earthquake inspections, and response.

Conference Paper↗

USGS2022

Earthquake scenario selection for portfolio holders in CEUS: A case study with Oklahoma DOT

Portfolio managers of spatially distributed assets in the central and eastern United States (CEUS) and other low- to moderate seismic hazard regions require scenario-based seismic risk assessment for the purpose of emergency management and planning. Uncertainties regarding the long-term seismicity of the region, unknown faults, and limited historical records complicate the selection of an earthquake scenario. Through a case study with the Oklahoma Department of Transportation (ODOT) and their portfolio of bridges, we look at one such exercise, which consists of two scenario earthquakes: one scenario earthquake selected from the U.S. Geological Survey Building Seismic Safety Commission (BSSC) scenario catalog, a magnitude (M) 7.2 event on the Meers fault, and a second aftershock selected by the consequence-driven earthquake scenario selection (Co-DESS) method. The latter is driven by ODOT’s desired service actions to be included during the earthquake drill; in this case, we identify an earthquake that is likely to trigger inspections for bridges across multiple districts, thereby testing not only inspection protocols but also coordination efforts between district groups. We find that the Co-DESS selected event is smaller in magnitude and offers different geographical options than selection through conventional selection methods, while still meeting necessary consequences for an effective earthquake exercise.

Conference Paper↗

USGS2020

Earthquakes, ShakeCast

ShakeCast® – short for ShakeMap Broadcast – is a fully automated software system for delivering specific ShakeMap products to critical users and for triggering established post-earthquake response protocols. ShakeCast is a freely available, postearthquake situational awareness software application that automatically retrieves earthquake shaking data from ShakeMap to compare ground shaking intensity measures against users’ facilities (Lin and Wald 2008). ShakeCast then generates potential damage assessment and inspection priority notifications, maps, and web-based products for critical users, emergency managers, and those on a need-to-know basis.

Book chapter↗

USGS2020

An update of USGS bear-real-time earthquake shaking and impact products

We report on advancements in both hazard and consequence modeling that form the core of the U.S. Geological Survey’s (USGS) strategy to improve rapid earthquake shaking and loss estimates. Whereas our primary goal is to improve our operational capabilities of the USGS National Earthquake Information Center, the science, software, and datasets behind these systems continue to advance uses and studies of earthquake shaking and impact by the seismological, engineering, financial, and risk modeling communities. Several important updates to our integrated shaking and impact products are outlined and we introduce new earthquake information products that have recently been brought online, including rapid ground failure estimates and more spatially refined loss estimates domestically (in the U.S). We continue to compile, develop, and refine key openly available models and datasets that contribute to calibrating these systems and report on the collection and storage of new inventories. We also describe some of the basic operational considerations in the current generation of these shaking and loss-estimation systems. A key aspect of the product integration and development is leveraging earthquake-hazard and loss-modeling science done internally (within the USGS) and by external researchers and collaborators. Lastly, we outline new opportunities for further research and development by emphasizing scientific, data, and application gaps and challenges that must be solved in order to improve our shaking and impact information tools.

Conference Paper↗

USGS2020

Assessing the long-term earthquake risk for the US National Bridge Inventory (NBI)

We estimate annualized earthquake loss associated with over 600,000 bridges located throughout the contiguous United States. Each year, the Federal Highway Administration, in partnership with State Departments of Transportation, undertake a massive exercise to update the National Bridge Inventory (NBI) by combining data from states, federal agencies, local jurisdictions, and tribal governments. The NBI captures pertinent details related to individual bridges (e.g., their usage, repairs, or retrofits). We make use of the 2018 NBI that contain the necessary engineering attributes needed to assign the appropriate Hazus bridge class for each bridge, which can then be used for engineering risk analyses. Basic structural data, component dimensions, and regional replacement cost factors are used to develop an economic exposure model. This is a significant improvement over previous replacement costs, and as a result of this study, results are now available within the Federal Emergency Management Agency’s Hazus platform. Earthquake hazard is defined using the U.S. Geological Survey’s 2018 National Seismic Hazard Model. For each bridge location, we obtain an earthquake shaking hazard curve defined in terms of spectral acceleration at a vibration period of 1.0 sec, ensuring that it properly reflects the site-specific soil conditions. We then integrate it with the bridge-specific fragility curve to compute annual probabilities of exceeding various damage states. Next, we perform economic loss analyses using the repair costs associated with specific damage states, resulting in an estimate of mean total annual financial loss for each bridge; this long-term measure of seismic risk enables us to illustrate the distribution of overall financial risk with respect to geographical region, era of construction, or type of bridge.

contiguous United States↗

USGS2018

State transportation agencies partner to deploy and enhance ShakeCast

The California Department of Transportation (Caltrans) is organizing and leading a three-year Transportation Pooled Fund (TPF) project, Connecting the Dots: Implementing ShakeCast Across Multiple State Departments of Transportation for Rapid Post-Earthquake Response. Ten state Departments of Transportation (DOT)—CA, ID, MO, MS, OK, OR, SC, TX, UT, AND WA—have partnered and combined research funds to pursue implementation and advancement of the U.S. Geological Survey’s (USGS) ShakeCast system. ShakeCast is a software application that automatically retrieves ShakeMap shaking estimates and performs analyses using fragility functions for bridges, buildings, and other structures. The ShakeCast system identifies which facilities are most likely impacted by an earthquake and sends notifications to responders in the minutes after an earthquake. By focusing inspection efforts on the most damage-susceptible facilities in the severely shaken areas, ShakeCast can reduce response time and priorities for bridge inspections in the aftermath of a significant earthquake. The goal of the TPF project is to establish or enhance operational ShakeCast instances for all the partner DOTs, while advancing transportation-focused aspects of the software platform. DOTs are uniquely able to take advantage of the ShakeCast technology in that bridge fragilities can be readily derived from the National Bridge Inventory (NBI). DOTs also share the need for prioritized response strategies given their very large numbers of facilities—over wide areas—that have varying vulnerabilities, many of which could potentially be affected by earthquake shaking. The ten-state TPF project will also explore opportunities for DOT-specific ShakeCast software modifications, for example, for enhanced neighboring-state situational awareness and response coordination as well as for long-term maintenance and operations of their ShakeCast systems.

Conference Paper↗

USGS2017

Development and utilization of USGS ShakeCast for rapid post-earthquake assessment of critical facilities and infrastructure

The ShakeCast system is an openly available, near real-time post-earthquake information management system. ShakeCast is widely used by public and private emergency planners and responders, lifeline utility operators and transportation engineers to automatically receive and process ShakeMap products for situational awareness, inspection priority, or damage assessment of their own infrastructure or building portfolios. The success of ShakeCast to date and its broad, critical-user base mandates improved software usability and functionality, including improved engineering-based damage and loss functions. In order to make the software more accessible to novice users—while still utilizing advanced users’ technical and engineering background—we have developed a “ShakeCast Workbook”, a well documented, Excel spreadsheet-based user interface that allows users to input notification and inventory data and export XML files requisite for operating the ShakeCast system. Users will be able to select structure based on a minimum set of user-specified facility (building location, size, height, use, construction age, etc.). “Expert” users will be able to import user-modified structural response properties into facility inventory associated with the HAZUS Advanced Engineering Building Modules (AEBM). The goal of the ShakeCast system is to provide simplified real-time potential impact and inspection metrics (i.e., green, yellow, orange and red priority ratings) to allow users to institute customized earthquake response protocols. Previously, fragilities were approximated using individual ShakeMap intensity measures (IMs, specifically PGA and 0.3 and 1s spectral accelerations) for each facility but we are now performing capacity-spectrum damage state calculations using a more robust characterization of spectral deamnd.We are also developing methods for the direct import of ShakeMap’s multi-period spectra in lieu of the assumed three-domain design spectrum (at 0.3s for constant acceleration; 1s or 3s for constant velocity and constant displacement at very long response periods). As part of ongoing ShakeCast research and development, we will also explore the use of ShakeMap IM uncertainty estimates and evaluate the assumption of employing multiple response spectral damping values rather than the single 5%-damped value currently employed. Developing and incorporating advanced fragility assignments into the ShakeCast Workbook requires related software modifications and database improvements; these enhancements are part of an extensive rewrite of the ShakeCast application.

Conference Paper↗