Estudo em modelos físicos de aterro estruturado

Abstract

Geosynthetic-reinforced piled-supported embankment systems (GRPS) is an effective and economical technique for construction of embankments over soft soils, resulting in less settlements and shorter construction times, compared to other methods. A reinforced piled embankment is a single or multi-layer reinforced composite structure made of earth and geosynthetic. It bridges the soft soil between bearing elements. In those systems, embankment load is transmitted by three basic mechanisms: arching effect, tensile force developed by the geosynthetic reinforcement and the loads transferred to the soil between pile caps under the geosynthetic. Methods to design GRPS use analytical models of 2D or 3D solutions. Other methods use analytical solutions, combining monitoring data of real structures and physical models. This study evaluates the behavior of three large-scale physical models under plane-strain conditions considering induced settlements applied at different stages of construction. The prototype consists in a hydraulic platform elevator system simulating the soft soil settlement. Backfill is composed by granular well-graded material and surcharge is applied by a pneumatic load system. All the physical models were constructed at similar conditions, except for the construction sequence and compaction. Those models were assembled and instrumented to monitor the transference of load between the soil, pile caps and reinforcement. Settlements, mobilized tensions along the reinforcement and the total stress at the interface between the pile caps and soil were measured. The results were compared with analytical solutions and indicate good agreement with the design methodology of EHRLICH (2001, apud SALES, 2002).