This report presents the latest enhancements to the Pipe Assessment and Selection Software (PASS), developed in partnership with the North Carolina Department of Transportation (NCDOT). These improvements integrate new structural requirements, historical repair and rehabilitation methods, and mitigation strategies to provide comprehensive guidance on culvert pipe service life. The updated NCDOT pipe material selection guide now incorporates dynamic adjustments based on structural specifications, enabling engineers to automatically modify fill heights and parameters to align with NCDOT standards. PASS employs a weighted average approach to evaluate historical repair and rehabilitation methods and map their applicability to different pipe materials. This systematic method allows engineers to assess compatibility with existing infrastructure and select the most suitable repair strategies based on design life, corrosion resistance, and cost-effectiveness. The inclusion of mitigation strategies allows engineers to factor subsurface exposure into their analysis. The software models the effects of various mitigation approaches, such as flowable fill, compacted clay liners, geosynthetic clay liners, and polymeric liners, to assess their impact on extending service life. Advanced one-dimensional modeling enables PASS to calculate optimal mitigation strategies by considering exposure conditions, soil properties, and chloride concentrations. A service life evaluation model is also included in PASS to predict the longevity of different pipe materials under varied environmental and structural conditions. This analysis ensures engineers can align rehabilitation measures with NCDOT standards and provide cost-effective solutions. A detailed user manual guides NCDOT engineers through the software’s features and capabilities, ensuring seamless implementation into their workflow. With PASS, engineers can evaluate project-specific parameters efficiently and select the most suitable pipe materials while ensuring optimal repair, rehabilitation, and mitigation strategies. Overall, the enhancements to PASS deliver a versatile tool that supports improved decision-making, aligns with NCDOT standards, and promotes sustainable transportation infrastructure. The software empowers engineers to better assess and maintain culvert pipes, reducing long-term maintenance costs and strengthening the state's infrastructure network.
