BACKGROUND

For many years, transportation agencies have dealt with the aftermath of flooding from major natural events. Climate change is making the threat of flooding more imminent. The resilience of pavement systems subjected to flooding will gain greater significance in the foreseeable future.

The Federal Highway Administration’s (FHWA) Technical Brief on Climate Change Adaptation for Pavements (FHWA-HIF-15-015) provides an introduction to how pavements may be fortified against climate change impacts due to extreme conditions, such as longer heat waves and severe flooding, and explains how these changes will accelerate the deterioration of highway pavements. However, it recognizes that the state of the practice is largely limited to general observations, and support is needed to develop specific adaptation strategies.

OBJECTIVES

The objectives of this research are to:

1. Develop a guide for state departments of transportation (DOTs), local agencies, and practitioners to help quantify the effect of flooding on pavement systems, and improve pavement system resilience during planning, design, construction, operation, and maintenance in flood-prone areas.

2. Develop a framework for state DOTs to incorporate analyses, material characterization, and other tools to consider the effects of flooding into mechanistic-empirical pavement design.

The accomplishment of the project objectives will require at least the following tasks.

TASKS

PHASE I — Planning

Task 1. Conduct a critical literature review of relevant research about how flooding affects pavement systems and their performance. The review shall include published and unpublished research and national, international, state, and other available research. Proposers may conduct a survey of selected state DOTs to learn about current approaches and practices related to flooding of pavement systems.

Task 2. Synthesize Task 1 to identify important elements and key factors that can contribute to the accomplishment of the project’s objectives. These elements and key factors should be addressed in this research as budget permits, or in the recommendations for future research. Summarize and document the results in Technical Memorandum 1.

Task 3. Develop a detailed research plan to achieve the research objectives and address the important elements and key factors identified in Task 2.

The research plan shall also include the following at a minimum:

• Identify parameters, measurements, and testing techniques and protocols that will be used to assess the impact of flooding on pavement systems;
• Develop a methodology to quantify and compare the resilience of different pavement systems and the effectiveness of the different pavement system components for improving resilience;
• Develop implementable methodologies/strategies/practices to improve pavement system resilience during planning, design, construction, operation, and maintenance in flood-prone areas; and
• Identify other infrastructure systems (e.g., pipes, culverts, stormwater management elements, irrigation systems, etc.) that may adversely affect pavement system resilience and recommend practical mitigation strategies.

Task 4. Propose a preliminary outline for the guide.

Task 5. Prepare Interim Report No. 1 that documents the research performed in Tasks 1 through 4 no later than 6 months after the contract award. Include an updated work plan for Phases II and III describing the process, rationale, and how these updates contribute to the accomplishment of the research objectives.

PHASE II — Execution of Research Plan

Task 6. Execute the approved research plan according to Interim Report No. 1.

Task 7. Prepare Interim Report No. 2 that documents Task 6 and provides an updated work plan describing the rationale and process for the remainder of the research.

PHASE III — Final Products

Task 8. Update the guide based on the comments provided by the NCHRP project panel.

Task 9. Prepare the final deliverables including the guide and the following:

a. The proposed framework for mechanistic-empirical pavement design.

b. A stand-alone technical memorandum titled “Implementation of Research Findings and Products”. See Special Note J for additional information.

c. Materials for a webinar intended for DOT staff and other practitioners to disseminate the project’s results, guidelines, practices, and other findings of the project. The duration of the webinars will be established considering the most effective way of communicating the results of the project. Schedule and deliver two webinars.

d. A final report that documents the entire research effort.

PROJECT DEFINITIONS

Proposers must consider these definitions for this NCHRP project.

Resilience – The ability to anticipate, prepare for or adapt to conditions or withstand, respond to, or recover rapidly from disruptions, including the ability

A.(i) to resist hazards or withstand impacts from weather events and natural disasters; or (ii) to reduce the magnitude or duration of impacts of a disruptive weather event or natural disaster on a project; and

B. to have the absorptive capacity, adaptive capacity, and recoverability to decrease project vulnerability to weather events or other natural disasters. 23 United States Code 101(a)(24)

Flooding – unanticipated moisture changes within a pavement system due to climate-related and human-caused events.

Pavement System – All the different layers and materials constructed to support and distribute traffic loads to the non-engineered roadbed material.

STATUS: Research in progress.