Bridges

Bridges are designed to function for 100 years but often the costs of maintenance are very significant. Bearings and expansion joints which affect the performance of a bridge are mainly the source of maintenance cost. In this case, an integral bridge can be an interesting alternative since there is no need for bearing and expansion joint installation.

An integral bridge is a soil interactive structure and all the lateral movements also need to be considered in the design. In order to reduce the lateral earth pressure and accommodate the cyclic lateral movements without having to account for significant actions on both super and substructure and also to reduce the construction time, an alternative backfill is proposed. The proposed backfill consists of a compressible inclusion (CI) attached to the back of the abutment wall with a suitably detailed rigid backfill in lieu of conventional special backfill. This will significantly reduce the duration for the construction of the abutment backfill and a better design outcome for the abutment wall and deck. In this paper, a brief summary of the material characteristics of the compressible material and the bridge translation performance based on the analysis for two integral bridges is provided. The proposed backfill reduces the cost as the overall cost of installation comparing to the mechanically stabilised earth and prevents the development of backfill settlement and void development below the approach slab due to long-term abutment movements.