Analysis of Behavior of Embankments on Soft Soils Geotechnical Investigations and Instrumentation Access of Embank Ments the Jitituba River Bridge

The present work will be analyzing the access embankments of the Jitituba River Bridge, placed on the Highway AL- 413, km 12,9 – São Luiz do Quintude, a small city next to Maceió, AL, Brazil, where this bridge was built, even before the access embankments. Due to the presence of a soft soil thick layer, that measures up to 12 meters of thickness, and to the construction sequence of the bridge embankments, there was a need to analyze not only its stability but also its general rupture and its vertical displacements, commonly considered in the projects of embankments of soft soils, as well as the stability to reduce the horizontal displacements and the consequent efforts to transverse the piles through the bridge. The solution adopted consisted in the construction of embankments by stages, allied to the use of prefabricated vertical drains and geotechnical instrumentation (Casagrande piezometers, plates of settlement an inclinometers) to control and follow the project performance. The geotechnical investigations consisted on field tests (standard penetration test SPT with natural water content profile and vane test) and lab tests (characterization, radial and vertical consolidation, compression triaxial UU and CIU). Starting from the project data given by Gusmão Associated Engineers and the geotechnical investigations and instrumentation, the behavior of the access embankments was analyzed in relation to the measures of pore-pressures, vertical and horizontal displacements, through the application of several methods and models proposed in the bibliography and of the comparison with other cases of embankments on soft soils. Standing out, the analyses of consolidation, compressibility and control of stability.