Poroelastic modeling of pore pressure development in granular pavement layers

ABSTRACT

Moisture excess in granular pavement layers can decrease pavement performance leading to moisture-related distresses. The combination of trapped water and heavy traffic loads may substantially increase pore pressure and lead to shear failure if layer hydraulic conductivity is insufficient. Currently, most pavement analysis models are unable to predict pore pressure development, so the design and evaluation methods ignore this dynamic effect which may significantly underestimate the moisture damaging effect on pavements. This paper proposes the use of Biot’s poroelasticity theory for modelling fully saturated unbound materials. The proposed methodology – Poroelastodynamic Finite Integration Technique (PEFIT) – was used to analyze axisymmetric multilayered pavement structures consisting of elastic and poroelastic layers. The model was verified and validated using a well-known commercial finite element solver and field pore pressure data, respectively. A sensitivity analysis was conducted by varying critical pavement design parameters. The PEFIT analysis of a three-layer pavement system with a poroelastic base layer has shown that a decrease in base hydraulic conductivity significantly increases the maximum pore pressure, especially for high-speed loads. Results also indicate substantial pore pressure and water movement in the base layer, which may induce a potential shear failure mechanism for unbound materials.

KEYWORDS:

• Pavement design
• moisture
• granular layers
• poroelastic materials
• hydraulic conductivity

Acknowledgements

The authors would like to express their gratitude to the University of Pittsburgh Anthony Gill Endowed Chair for the financial support for this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.