Washington State Bridge Resiliency Assessment Data

The 2,717 state highway bridges incorporated into this study from the WSDOT bridge inventory database were assessed using the BSST analysis methodology detailed previously in this report. Results consist of three types of outcomes: Bridge Damage Levels and Types, Bridge Repair Types, and Bridge Reopening Times. All output is a part of this feature class. Bridge damage types are projected on the basis of both damage level (None, Moderate, Significant), whether a bridge is a special bridge type, and also the types of damage that the bridge will experience (including both direct seismic and secondary earthquake-induced impacts); The projected repair types and reopening times necessary to bring bridges back to a minimum level of functionality that enables their use for emergency response were computed using the methodology specified in the Bridge Reopening Times section. Refer to the BSST Technical Report. The BSST was developed to assess the potential impacts of a CSZ earthquake to highway bridges in Washington State at a system-level as part of the Washington State Transportation Systems RRAP project. The results provided identify the Damage Levels, Damage Types, Repair Types and Reopening Times associated with 2,717 bridges located in Western and Central Washington that were evaluated for this RRAP project. Understanding that this analysis likely constitutes a “worst-case scenario” with respect to bridge damage, the results nonetheless project that the majority of bridges in Washington State will experience moderate to significant damage resulting from a CSZ earthquake. While the majority of bridges that experience damage could be reopened within one year of the earthquake, a substantial number of those bridges (28.7 percent) are projected to take more than a year to reopen—in many cases 2 or more years. The results also project that while many bridges may be reopened after either minor repairs/inspections or the construction of a temporary bypass road, a substantial number of more significantly damaged bridges (797 structures) span bodies of water and will require complete replacement prior to reopening. This suggests that significant gains in roadway corridor reopening times could be gained by focusing on retrofits or upgrades to these more vulnerable bridges that span rivers and other bodies of water. This tool is primarily intended to inform regional highway prioritization for emergency response activities; however, the BSST provides a useful evaluation methodology that could be applied to other regional emergency preparedness and infrastructure assessment studies. This could include studies of bridge infrastructure to other potential seismic events within the region, or at varying jurisdictional levels (i.e., county, local). The BSST also uses currently available seismic, seismically-induced secondary hazard and infrastructure information. As new seismic information becomes available, or as secondary-hazards (e.g., landslides, avalanches) become characterized more comprehensively, such information could be integrated into the current BSST methodology. Similarly, as seismic retrofit activities or other infrastructure improvement projects continue throughout Washington State, or as new infrastructure are built, it will be important that the infrastructure data integrated in the BSST also be updated periodically. Doing so will ensure that planners and infrastructure managers maintain the most current and complete understanding of the network-level seismic risks of a CSZ event to Washington State highways.Please note that all results from the BSST are based on a model and information received from WSDOT. Damages from an earthquake may be different that what is provided here. Liquefaction data was used within the BSST tool. WADNR is the source for liquefaction data and is available here: https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps#nehrp-site-class-and-liquefaction-susceptibilityUSGS ShakeMap was also used in the BSST tool for a M9.0 Cascadia earthquake and is available here: https://earthquake.usgs.gov/scenarios/eventpage/gllegacycasc9p0expanded_se/shakemap/pga. DHS distributed this data to WSDOT on August 22, 2019. UPDATE: 5/5/2025. Some structure ID's have been corrected (most typically a 0 or 00 added to the beginning of the State Structure ID), and structures that have been removed or rebuilt have been removed from this dataset. In all 140 records were either corrected or deleted.本研究从华盛顿州运输部（Washington State Department of Transportation, WSDOT）桥梁库存数据库中遴选的2717座州级公路桥梁，采用本报告前文详述的桥梁地震安全评估工具（Bridge Seismic Safety Tool, BSST）分析方法开展评估。评估结果包含三类输出：桥梁破坏等级与破坏类型、桥梁修复方案，以及桥梁恢复通行时间，所有输出均属于本要素类的组成部分。桥梁破坏类型的预测依据包括破坏等级（无破坏、中等破坏、严重破坏）、桥梁是否为特殊桥型，以及桥梁将遭受的破坏类型（涵盖直接地震破坏与地震诱发的次生灾害破坏）；使桥梁恢复至满足应急响应使用需求的最低功能水平所需的预估修复方案与恢复通行时间，则采用《桥梁恢复通行时间》章节中规定的方法计算得出，具体细节可参阅《BSST技术报告》。 BSST作为华盛顿州运输系统区域韧性与适应计划（Regional Resilience and Adaptation Plan, RRAP）项目的组成部分，旨在从系统层面评估卡斯卡迪亚俯冲带（Cascadia Subduction Zone, CSZ）地震对华盛顿州公路桥梁的潜在影响。本次评估针对参与本RRAP项目的华盛顿州西部与中部地区的2717座桥梁，所提供的结果明确了各桥梁对应的破坏等级、破坏类型、修复方案与恢复通行时间。 尽管本分析大概率属于桥梁破坏场景下的「最坏情况」，但预估结果显示，华盛顿州境内绝大多数公路桥梁将在卡斯卡迪亚俯冲带地震中遭受中等至严重破坏。虽然多数受损桥梁可在震后一年内恢复通行，但仍有28.7%的桥梁预估恢复通行时间超过一年，部分桥梁甚至需要2年及以上方可恢复通行。 评估结果同时显示，尽管许多桥梁仅需开展小型修复/检查或搭建临时绕行道路即可恢复通行，但仍有797座受损更为严重的桥梁跨水域分布，需在恢复通行前进行完全更换。这表明，针对这些跨河流及其他水域的脆弱桥梁开展加固改造或升级，可大幅缩短道路走廊的恢复通行时间。 本工具主要用于为应急响应活动下的区域公路优先级规划提供决策参考；不过，BSST所提供的评估方法也可应用于其他区域应急准备与基础设施评估研究，包括针对本区域内其他潜在地震事件的桥梁基础设施研究，或不同管辖层级（如县级、地方级）的相关研究。 BSST同时采用了当前可获取的地震、地震诱发次生灾害及基础设施相关数据。随着新地震信息的公开，或次生灾害（如滑坡、雪崩）的特征得到更全面的刻画，相关数据可被整合至当前的BSST分析方法中。同理，随着华盛顿州境内地震加固活动或其他基础设施改善项目的持续推进，或新建基础设施的落成，BSST中集成的基础设施数据也需定期更新，以确保规划人员与基础设施管理者能够及时、全面地了解卡斯卡迪亚俯冲带事件对华盛顿州公路路网的系统性震害风险。 请注意，BSST的所有结果均基于模型与从WSDOT获取的信息。地震实际造成的破坏可能与本结果存在差异。BSST工具中使用了液化数据，该数据的来源为华盛顿州自然资源部（Washington Department of Natural Resources, WADNR），公开获取链接为：https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps#nehrp-site-class-and-liquefaction-susceptibility。此外，BSST工具还针对M9.0级卡斯卡迪亚地震使用了美国地质调查局（United States Geological Survey, USGS）震动图（ShakeMap），公开获取链接为：https://earthquake.usgs.gov/scenarios/eventpage/gllegacycasc9p0expanded_se/shakemap/pga。该数据由美国国土安全部（Department of Homeland Security, DHS）于2019年8月22日分发至WSDOT。 更新记录：2025年5月5日。已修正部分结构ID（通常为在州级结构ID开头添加0或00），并从本数据集中移除了已拆除或重建的桥梁结构。本次共计修正或删除了140条记录。