Parametric Analysis on an IAB Superstructure

Integral abutment bridges(IABs) are jointless bridges where the girder or the deck is continuous and connected monolithically to the abutments.A usual and important problem in the design of IABs is how to deal with the soil-structure interaction behind the abutments and next to the foundation piles: this can be considered as a fundamental aspect for the thorough understanding of this type of structures,which requires iterative and nonlinear analysis.In this paper,a 2D simplified finite-element model of a real 400 meters long IAB,built in the Province of Verona-Italy,is implemented and used to perform non linear analysis on the bridge,whose superstructure response is examined in details in the present paper.Then,the results obtained from a parametric study on the IAB,where the soil properties are varied behind the backwall and adjacent to the piles are varied,are described.In the end,a pushover analysis is carried out to assess the failure pattern of the bridge due to temperature change,considered as one of the key parameters in IABs design;finally,the effect of abutment stiffness is also discussed.The case study presented represents the world record for this kind of bridges.Authors believe this can be a cost effective and an efficient strategy to improve the durability and extend the life span of commonly built simply supported flyovers prone to maintenance problems due to bearings and expansion joints durability.

Integral abutment bridges （IABs） are jointless bridges where the girder or the deck is continuous and connected monolithically to the abutments. A usual and important problem in the design of IABs is how to deal with the soil-structure interaction behind the abutments and next to the foundation piles： this can be considered as a fundamental aspect for the thorough understanding of this type of structures, which requires iterative and nonlinear analysis. In this paper, a 2D simplified finite-element model of a real 400 meters perform non linear analysis long IAB, built in the Province of Verona-Italy, is implemented and used to on the bridge, whose superstructure response is examined in details in the present paper. Then, the results obtained from a parametric study on the IAB, where the soil properties are varied behind the backwall and adjacent to the piles are varied, are described. In the end, a pushover analysis is carried out to assess the failure pattern of the bridge due to temperature change, considered as one of the key parameters in IABs design; finally, the effect of abutment stiffness is also discussed. The case study presented represents the world record for this kind of bridges. Authors believe this can be a cost effective and an efficient strategy to improve the durability and extend the life span of commonly built simply supported flyovers prone to maintenance problems due to bearings and expansion joints durability.