Study of Mechanically Stabilized Earth Structure Supporting Integral Bridge Abutment

Abstract

This paper will present the effects of the loading from an integral bridge abutment on a Mechanically Stabilized Earth (MSE) retaining wall structure. The analysis will mainly concentrate on the effects of thermal deformation phenomenon (contraction and expansion) of the bridge deck on an MSE wall structure and more particularly the induced tensile force in soil reinforcements and lateral displacement at the front face of the wall as a result of the bridge movement. A geotechnical numerical finite difference program, FLAC v5.0 2D, will be utilized to model a standard abutment (true bridge abutment on bearings) and an integral bridge abutment (bridge deck and beam seat rigidly connected). The paper will also discuss the concept, components and applications of numerical modeling results in design and construction of the MSE structures supporting standard and integral bridge abutments. The results of the two models will be compared to an empirical design methodology as developed based upon American Association of State Highway and Transportation Officials (AASHTO) design guidelines. Increasingly more complex design and construction techniques are being used for MSE walls, similar to the cases discussed in this paper, which makes the use of accurate design tools such as numerical modeling an effective verification of design assumptions.