Full Height Frame Integral Bridges Abutment-Backfill Interaction in Loose Granule Backfill

Abstract

The abutment wall behavior of full height frame integral bridges in loose granule backfill under temperature changes was investigated within this study. Since, the effect of backfill soil resistance on behavior of abutment wall movement was mostly neglected in previous researches, the abutment-backfill interaction was selected as the research study area and therefore, deriving the final abutment displacement profile was set as the research objective. In frame abutment integral bridges, the superstructure is encased into the abutment wall in which produces a fixed connectivity. This connection results in the same movement of abutment top elevation and the bridge superstructure. Furthermore, the abutment is mostly built in reinforced concrete, thus it acts as a rigid mass with a linear deformation behavior. With regard to these points and applying a new method for calculation of bridge deck displacement, the abutment deformation profile was formulated. In the new applied method, the final bridge deck displacement was expressed as a function of backfill soil resistance utilizing some available correlations due to soil behavior, such as British Standard, Massachusetts, Canadian and Husain-Bagnaroil. Fortunately, the results obtained from these correlations were in a close agreement with each other, which confirmed the integrity of applied method. Moreover, a finite element model was built in SAP2000 for this case and subsequently the outcomes were compared with the results of applied method. It was seen that both results were consistent and in most of the cases, the British Standard concluded the closets results to the finite element as compared with the others.