Concrete integral abutment bridges with reinforced concrete piles

The use of reinforced concrete (RC) piles in integral abutment bridges (IABs) has not been widespread due to concerns over pile flexibility and the potential for concrete cracking. This is the reason why the use of steel piles is the preferred solution in the United States. However, in various countries where IABs are still seldom used, RC piles are more readily available and economical. Hence, an understanding of the behaviour of IABs with RC piles can lead to a wider implementation of integral solutions. This paper presents the results of a parametric study conducted to evaluate how both the design variables and the accuracy of the modelling approach influence the potential use of integral solutions with RC piles in prestressed concrete bridges up to 200 m long. Finite element modelling was used and four levels of approximation (LoA) were established for the analyses, ranging from simple linear-elastic to more complex non-linear models. The results show that existing concerns over concrete cracking control can be overcome if adequate options in design are used together with the adequate LoAs in structural analysis. Integral solutions with RC piles for bridges up to 200 m long can generally be adopted, although in comparisons with non-integral designs a significant additional amount of prestressing steel is to be expected. The results also include a set of charts with practical estimates to help designers in their first approach to the preliminary design of an IAB.