Reliability-Based Robust Design Framework for Rigid Pavements

Many uncertainties are associated with traffic, climate, structural, and material inputs in the pavement design. Over years, numerous efforts have been dedicated to developing methods to account for these uncertainties in the pavement design. While the traditional AASHTO design guide for rigid pavement design is able to quantify the effect of input uncertainties on the designed pavement service life, the selected design is still highly affected by the accuracy of statistical characterization of the uncertainties. Following AASHTO design guide, the slab thickness of the pavement is chosen without considering the uncertainties in the input parameters which can lead to over-design or under-design. In the past decade, in geotechnical engineering, a new approach called Robust Geotechnical Design (RGD) was developed to find a design which is less affected by the uncertainties in input parameters and the adopted models (called robust, herein). The core of this approach is based on quantifying the resiliency of the design to changes (referred to as robustness, herein). Once the robustness measure is defined, RGD considers safety, design robustness, and cost efficiency, simultaneously. To account for the existing uncertainties affecting the AASHTO design of rigid pavements and reduce their effect on the system response while being cost-efficient, this paper adopts the reliability-based robust design approach. And, to ease the calculation of multi-objective optimization considering cost, robustness, and safety, the simplified RGD approach is used herein. The results obtained from this analysis are compared with the current practice to show the benefits of the proposed approach.