Most civil engineering structures are subjected to cyclic loading during their service life, such as retaining walls, wave loading on offshore structures, seismic loading and traffic loading of pavements. In the case of integral abutment bridge (IAB), as an example, the backfill granular material is subject to slow cyclic stress and strain changes under drained conditions. These bridges are constructed so that the top deck is longitudinally continuous. In other words, IABs are joint-less bridges where the superstructure is connected with the abutment. The rigid connection enables the abutment and superstructure to act as a single structural unit, i.e. the expansion joints which are widely used in traditional bridges are removed in IABs. This removal is mainly due to the high maintenance expenditure. The behavior of the IABs is dominated by the cyclical temperature changes in the bridge deck. This results in imposition of cyclical horizontal displacements to the backfill soil of the abutments. The present research is an effort to investigate the induced passive pressure on the IABs, using a laboratory model and analytical approach. The results indicate that the passive pressure distribution is non-linear and its maximum value along the wall is dependent on the magnitude of the wall rotation and number of cycles. It seems two different mechanisms for this behavior. In the above part of wall, sand behaves as a plastic material. A decline in passive pressure in the bottom part, however, is the result of forming an arching.

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