Deformation characteristics of the backfill on GRS integral bridge by thermal horizontal cyclic displacements at the facing

Abstract

A new bridge system comprising of a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid facings that are unified with a girder, without using girder supports, is proposed. A series of 1g model loading tests of GRS Integral bridge were performed to evaluate the effects of the followings factors on the residual earth pressure and settlement of backfill by thermal cyclic horizontal displacements of the facing; a) connection between the reinforcement and the facing, b) displacement mode of the facing, and c) the amplitude of cyclic horizontal displacement of the facing. The backfill settlement by cyclic horizontal displacements cannot be effectively reduced by reinforcing the backfill when the reinforcement is not connected to the facing. Furthermore, an increase in the earth pressure becomes larger than when the backfill is not reinforced. These problems are amplified with an increase in the facing displacement. All these problems are solved by connecting the reinforcement to the facing.