Earth reinforced technology has been greatly developed in recent years. Mechanically Stabilized Earth (MSE) systems have three major components: reinforcing elements, facing systems, and reinforced fill. Reinforcing elements may be classified by stress/strain behavior and geometry. Generally, in terms of stress/strain behavior, reinforcing elements may be considered inextensible or extensible. Metallic reinforcements are usually considered as inextensible; polymeric reinforcements can be extensible and/or inextensibleones as extensible is not always exact. Based on their geometric shapes, reinforcements can be categorized as strips, grids or sheets. Vertical walls with concrete panels facing and steel bars reinforcement are technologies commonly used worldwide. These structures are usually designed with the Coherent Gravity Method ( Anderson et al., 2010) or with the Simplified Method, based on the assumption that reinforcement is inextensible. Nowaday, some types of these walls are built using polyester geostrip reinforcements in place of steel bars. Since the tensile stiffness of the geostrips is much larger than that typical of geosynthetic sheets, geostrips could be assumed to behave as inextensible reinforcement as well. Further researches, however, are required to ensure that such an assumption is correct. Two reinforced soil walls, have been built and fully instrumented at the Maccaferri establishment of Jundiai, Brazil. The first wall retained a sand backfill while the second retained a silt backfill. The walls were built with concrete panels facing and polyester geostrip reinforcements. This system is characterized by high tensile strength reinforcements anchored to a concrete vertical facing. The strips had been inserted horizontally within the backfill during construction. The aim of the experimental full scale model was to measure stress and deformations on soil, strips and concrete facing. A research agreement between the Department of Civil Engineering and Architecture of University of Catania and Officine Maccaferri S.p.A, has been made in order to analyse the behaviour of these experimental walls. The research has been developed into two phases: the first phase was the characterization of the soil backfill of the experimental walls; the second phase was a FEM numerical analysis. During the first phase, laboratory tests for static and dynamic soil characterization have been performed. The analysed soil samples were named BRA-1, BRA-2, BRA-3, BRA-4. Samples BRA-1 and BRA-3 were made of sand while samples BRA-2 and BRA-4 were made of sand with a low silt percentage. Finally, during the last phase, a two-dimensional (2D) FEM analyses have been brought about to evaluate the walls performances in terms of stress and strain of soil, reinforcing elements and concrete panels, in the framework of the new performance-design approach.
Reinforced earth retaining walls with rigid facing panels: experimental tests on physical models, theoretical analyses and design codes references
Cavallaro A;
2014
Abstract
Earth reinforced technology has been greatly developed in recent years. Mechanically Stabilized Earth (MSE) systems have three major components: reinforcing elements, facing systems, and reinforced fill. Reinforcing elements may be classified by stress/strain behavior and geometry. Generally, in terms of stress/strain behavior, reinforcing elements may be considered inextensible or extensible. Metallic reinforcements are usually considered as inextensible; polymeric reinforcements can be extensible and/or inextensibleones as extensible is not always exact. Based on their geometric shapes, reinforcements can be categorized as strips, grids or sheets. Vertical walls with concrete panels facing and steel bars reinforcement are technologies commonly used worldwide. These structures are usually designed with the Coherent Gravity Method ( Anderson et al., 2010) or with the Simplified Method, based on the assumption that reinforcement is inextensible. Nowaday, some types of these walls are built using polyester geostrip reinforcements in place of steel bars. Since the tensile stiffness of the geostrips is much larger than that typical of geosynthetic sheets, geostrips could be assumed to behave as inextensible reinforcement as well. Further researches, however, are required to ensure that such an assumption is correct. Two reinforced soil walls, have been built and fully instrumented at the Maccaferri establishment of Jundiai, Brazil. The first wall retained a sand backfill while the second retained a silt backfill. The walls were built with concrete panels facing and polyester geostrip reinforcements. This system is characterized by high tensile strength reinforcements anchored to a concrete vertical facing. The strips had been inserted horizontally within the backfill during construction. The aim of the experimental full scale model was to measure stress and deformations on soil, strips and concrete facing. A research agreement between the Department of Civil Engineering and Architecture of University of Catania and Officine Maccaferri S.p.A, has been made in order to analyse the behaviour of these experimental walls. The research has been developed into two phases: the first phase was the characterization of the soil backfill of the experimental walls; the second phase was a FEM numerical analysis. During the first phase, laboratory tests for static and dynamic soil characterization have been performed. The analysed soil samples were named BRA-1, BRA-2, BRA-3, BRA-4. Samples BRA-1 and BRA-3 were made of sand while samples BRA-2 and BRA-4 were made of sand with a low silt percentage. Finally, during the last phase, a two-dimensional (2D) FEM analyses have been brought about to evaluate the walls performances in terms of stress and strain of soil, reinforcing elements and concrete panels, in the framework of the new performance-design approach.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
