LATERAL THRUSTS AND SETTLEMENTS ON A GRANULAR SOIL RETAINED BY A SEMI-INTEGRAL ABUTMENT UNDERGOING CYCLIC LATERAL DISPLACEMENTS WITH DIFFERENT AMPLITUDES

Resumo

Semi-integral abutment bridges are constructed without thermal expansion joints and the
superstructure-abutment system is not integrally connected to the substructure. In view of this peculiar
characteristics, the abutment undergoes combined movements of translation and rotation due to
expansion and contraction of the superstructure caused by temperature variations. Such behavior can
increase of lateral thrusts and vertical displacements in the soil close to the abutment. Therefore, this
work analyzed lateral thrusts and settlements on a granular soil retained by a semi-integral abutment
undergoing cyclic lateral displacements with different amplitudes. A finite element model was

developed and calibrated based on field data collected from an instrumented and monitored semi-
integral abutment. The soil stress-strain behavior was represented by a hyperbolic constitutive model

and the abutment lateral displacements were given by prescribed horizontal displacements. Predictions
with the elaborated numerical model were found to produce a good match with the field data. After
validation, numerical simulations with displacement amplitudes of ± 5 mm and ± 10 mm were carried
out. The passive lateral thrust increased with the lateral displacement amplitude, while the active
lateral thrust remained virtually the same in both amplitudes. The settlements, heaves and the
disturbance zone within the backfill soil behind the abutment increased with the lateral displacement
amplitude.