STRUCTURAL ANALYSIS OF RIGID PAVEMENTS WITH PUMPING (FINITE, ELEMENTS, PLATES)

JESUS SILVERIO LARRALDE, Purdue University

Abstract

Pumping has been considered a major contributor to premature failure in rigid pavements. The traditional design procedures, based on a stress-fatigue criterion, have been unsuccessful in providing pavements which accomplish their intended service lives. In addition to the stress-fatigue criteria, an erosion criteria must be considered. Concrete pavements have been analyzed using the Westergaard's equations, or charts developed from those equations. These methods assume full contact between the slab and subgrade, as well as continuity in the whole pavement structure. Recently, with finite element techniques, the consideration of discontinuities in the pavement structure has been possible. Nevertheless, in the traditional analysis methods, closed form solutions or finite element methods, the reduction of pavement strength resulting from the damage caused by traffic has not been considered. Fatigue damage caused by repetitive load applications reduces the strength and stiffness of the pavement. In this thesis, a nonlinear finite element method for analysis of rigid pavements which considers the decay of their stiffness properties due to fatigue damage is presented. The damge caused in the concrete slab, the load transfer devices, and the pavement foundation are considered. The computer scheme has been developed from the previously existing ILLISLAB code. The computer implementation presented herein, called PROP, has the following main features: nonlinear finite element method; orthotropic plate; consideration of reinforcement in concrete slab; resilient modulus of subgrade reaction; pumping development; determination of stresses and deformations at all nodal points; and determination of state of pavement damage. This method can be used for design and for prediction of maintenance requirements of rigid pavements.

Degree

Ph.D.

Subject Area

Civil engineering

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