The analysis of flexible pavements is usually carried out by using software based on the Linear Elastic Theory in axial-symmetric configuration, by assuming stresses are uniformly distributed over a circular footprint. The application of these methods requires simple computations, but beside this, the approximation of the real geometry with circular footprints causes erroneous results in the stress-strain response and therefore in the damage analysis. Rectangular footprint is closer to the real shape of the tire/pavement contact area. This paper aims to identify some relations to evaluate strains in pavements produced by rectangular footprint loads by an equivalent single or group of circular footprints. In order to achieve this goal, pavement response was evaluated for different variable combinations both by ViscoRoute 2.0 software, for the rectangular geometry, and by an elastic model, for the circular geometry in axial-symmetric configuration; results obtained by the two analyses were compared in order to develop two different models. The first model proposes a correction of the radius of the equivalent circular area to calculate strains beneath the center of the rectangular footprint. The correction calculated for different variable configurations were related to those variables regarded as significant by means of a multivariate regression. In the second model, in order to calculate strains outside the rectangular footprint, the superposition of circular footprints that better approximates the rectangular ones was determined.
STRAINS IN ASPHALT PAVEMENTS UNDER CIRCULAR AND RECTANGULAR FOOTPRINTS
LOSA, MASSIMO;
2014-01-01
Abstract
The analysis of flexible pavements is usually carried out by using software based on the Linear Elastic Theory in axial-symmetric configuration, by assuming stresses are uniformly distributed over a circular footprint. The application of these methods requires simple computations, but beside this, the approximation of the real geometry with circular footprints causes erroneous results in the stress-strain response and therefore in the damage analysis. Rectangular footprint is closer to the real shape of the tire/pavement contact area. This paper aims to identify some relations to evaluate strains in pavements produced by rectangular footprint loads by an equivalent single or group of circular footprints. In order to achieve this goal, pavement response was evaluated for different variable combinations both by ViscoRoute 2.0 software, for the rectangular geometry, and by an elastic model, for the circular geometry in axial-symmetric configuration; results obtained by the two analyses were compared in order to develop two different models. The first model proposes a correction of the radius of the equivalent circular area to calculate strains beneath the center of the rectangular footprint. The correction calculated for different variable configurations were related to those variables regarded as significant by means of a multivariate regression. In the second model, in order to calculate strains outside the rectangular footprint, the superposition of circular footprints that better approximates the rectangular ones was determined.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.