Experimental and numerical analyses on the antiseismic effectiveness of fiber textile for earthen buildings

Seismic risk represents one of major threats for earthen constructions. In case of earthquake, earthen buildings are exposed to horizontal forces, which induce tensile stresses not compatible with earthen materials, thus causing damage and collapse mechanisms. In last years, nets embedded in thin layers of earthen mortar on the external surface of walls have been proposed in order to strengthen the buildings against seismic actions. The effectiveness of such a system basically depends on the adhesion between net and earth and on the wall-net anchorage solution too. This paper presents the results of an experimental and a numerical analysis carried out in order to evaluate the effectiveness of retrofitting based on two types of natural fibers: jute and a coconut derivate. Experimental analysis comprised three-point bending tests on adobe bricks reinforced on the intrados with the natural fiber net. The experimental results were employed to carry out a numerical analysis through DIANA 9.6 with the goal of obtaining a numerical model useful to design retrofitting interventions