NRRA: Mechanistic Load Restriction Decision Platform for Pavement Systems Prone to Moisture Variations

Summary:

Excessive moisture influences pavement performance by increasing surface deflection and decreasing bearing capacity. Seasonal fluctuation of groundwater, flooding, and spring thaw can all lead to changes in soil moisture and consequently stress states. Load restriction during and after inundation plays a key role in service life and maintenance planning of pavement systems. However, current procedures are either empirical or based on regional historical practices and do not incorporate transient and forecasted moisture profile in pavement response. This signifies the need for a mechanistic, coupled, and risk-based load restriction decision platform to assess pavement performance and determine traffic allowances during and after periods of excessive moisture. The research discussed in this report responds to this need by: (1) identifying key mechanical and environmental stressors and pavement characteristics through system dynamics modeling of hydrological regimes, moisture-dependent material properties, and pavement response models; and (2) developing a mechanistic load restriction decision toolkit validated against independent linear elastic models and field deflection measurement data. System-based univariate and multivariate sensitivity analysis demonstrated how different soil and climatic variables impact the moisture-dependent surface deflection and post-flooding recovery time. Inspired by the outcome of the system dynamics modeling, the first generation of PaveSafe, a flooded pavement assessment app, was prepared and is now available. It is a user-friendly application designed for different agent expertise and application in pavement sections with different model inputs. It is expected that the next generations of PaveSafe will be more computationally efficient, involve more material and modeling options, and be adaptable with other pavement performance packages.

Final Deliverables:

• Report #NRRA202110

Related Materials:

• NRRA Project WebPage: Mechanistic Load Restriction Decision Platform for Pavement Systems Prone to Moisture Variations  - (Website)

Related Research:

• TPF15466L: Flooded Pavements Assessment App–Phase 2