This paper describes the road infrastructure found in California's national forests, their vulnerabilities, and specific measures that can be taken to adapt to projected climate change effects, thus minimizing damage from fires and storms. Over the past 40 years this region has been hit by numerous climate change-related events including droughts, major forest fires, major storms, and flooding. Billions of dollars in damage have been sustained and numerous lives lost. It is necessary now to assess vulnerabilities, rank resources at risk, and prioritize adaptation actions. The Forest Service has recently been involved in infrastructure vulnerability assessment and adaptation strategy projects involving climate model studies, interviews, a literature review, local workshops, website information, and publication of the project findings. Different agency vulnerability assessment methods have been reviewed to establish a functional assessment and risk analysis methodology. Efforts to mitigate the impacts of climate change have included greenhouse gas reduction from agency vehicles, evaluating alternative transportation routes, implementing energy-saving measures, and identifying stormproofing road design measures to reduce the vulnerability of roads to extreme climate-related events. Much of the effort has been the identification of road adaptation and resiliency measures, particularly measures that are practical and implementable at minimum cost. These measures include: routine road maintenance; relocating road segments as needed; adding trash racks and diversion prevention dips to prevent culvert failures; building stream simulation projects; protecting bridges from debris and scour; covering soil with deep-rooted vegetation; and using soil bioengineering stabilization and deep-patch shoulder reinforcement to prevent local slope failures.

Seismic resilience assessment is essential for maintaining the functionality of sheet-pile wharves in liquefiable soils, preventing significant damages and minimizing losses during earthquakes. This study delves into the seismic resilience of sheet-pile wharves, focusing specifically on the effectiveness of four different liquefaction countermeasure techniques: anchor lengths, cement deep mixing, stone columns, and soil compaction. As such, an advanced two-dimensional (2D) Finite Element (FE) computational framework is established, motivated by a typical large-scale sheet-pile wharf configuration. Within this framework, a recently developed multi-yield surfaces plasticity model is employed, with the modeling parameters calibrated through undrained stresscontrolled cyclic triaxial tests and a centrifuge test. Subsequently, the impacts of these liquefaction countermeasures on the seismic resilience of the sheet-pile wharves are systematically investigated. Additionally, the effectiveness of combining longer anchor lengths with the other three mitigation techniques to enhance the seismic resilience of the sheet-pile wharves are examined. It is demonstrated that the synergistic effects of different liquefaction countermeasures can further reduce the liquefaction potential, thereby improving the seismic resilience. Overall, the FE analysis technique and the resulting insights are highly significant for the seismic resilience assessment of equivalent sheet-pile wharves in liquefiable soils, particularly when implementing such liquefaction mitigation countermeasures.

In this study, the seismic resilience of granular column-supported road embankments on liquefiable soils is examined to enhance the understanding and seismic design of resilient transportation infrastructure. A nonlinear dynamic analysis of embankments on liquefiable soils is performed, and the results are validated against centrifuge test data. In the assessment, a functional analysis framework encompassing fragility, vulnerability, and restoration functions is employed to evaluate the robustness and recovery of embankments. The resilience of embankments is quantified by the comprehensive life-cycle resilience index (R), which considers various factors, such as the embankment height, the liquefiable soil thickness, and the area replacement ratio (AR) of granular columns. A simplified design method is proposed that involves a model for rapidly assessing the resilience state of embankments under varying seismic intensities. The analysis highlights the essential role of granular columns in mitigating liquefaction-induced damage during seismic events, improving robustness, and recovering postearthquake functionality, and a practical and reliable tool is developed for assessing embankment resilience across diverse seismic scenarios.