Effects of an abutment construction on soft soil on a neighbouring structure: Influence of different construction techniques using geosynthetics

The topographic and geological conditions of several regions in Brazil favour the formation of large deposits of soft soils. Sometimes this requires the use of innovative techniques to allow constructions of geotechnical works in these sites. The presence of deep soft foundation soils has led to an increasing number of reinforced bridge abutments being built in the last years. However, little is known on the behaviour of such works, particularly with respect to displacements and bending moments induced in the neighbouring bridge foundations due to the construction of the embankment. In this paper, hypothetical bridge abutments were modelled, with and without the presence of geosynthetic reinforcement, aiming to evaluate the effects of the embankment construction on the foundations of the neighbouring bridge. The effects of the use of vertical drains and piles with caps underneath the embankments were also investigated. The results obtained clearly indicated the potential of the use of reinforcement, vertical drains or piles to reduce damages to the foundations of neighbouring structures caused by embankment construction. The use of vertical drains in conjunction with geosynthetic reinforcement showed an important effect on the reduction of horizontal displacements and moments in the piles of the bridge.