Modeling the Fiber Addition Influence on the Small Strain Shear Modulus of Sand

VETTORELO, PAULA V.; CLARIÁ, JUAN J.

Indian Geotechnical Journal

Springer

Año: 2017 p. 196 - 204

0971-9555

The mechanical behavior of fiber reinforced soilshas been extensively studied in the last decades. Previousstudies have shown that inclusion of fibers increases theshear strength of the reinforced soil. However, the presenceof fibers can reduce, in some cases, the stiffness of thecomposite material. In this paper, we study the change on theinitial stiffness in alluvial sand reinforced with polypropylenefibers. A model based on Hertz elastic contact theory isdeveloped in order to explain the trends of shear wavevelocity and maximum shear modulus in the fiber reinforcedsand as the fiber content varies. The model assumes that theshear wave is transmitted through elastic distortions at thecontacts, so the stiffness of the contacts governs the initialshear modulus, which in turn is affected by fiber additions.Furthermore, the ratio between the amount of grain to fibercontacts and the total of contacts on the shear wave pathinfluence the maximum shear modulus. An experimentaltesting program involving confined compression tests withshear wave velocity measurements of unreinforced and fiberreinforcedsand specimens was undertaken to validate theproposed model trends. The model predictions were found tobe in good agreement with the experimental results.