Undrained behaviour of polypropylene fibre reinforced sandy soil under monotonic loading

ABSTRACT

Soil improvement using fibres is widely used in soil stabilisation to prevent sand liquefaction. In order to study the undrained behaviour and liquefaction resistance of sand reinforced with polypropylene fibres, a series of triaxial compressive tests were conducted on unreinforced and reinforced Chlef sand with different contents of polypropylene fibres (0, 0.3, 0.5 and 0.8%). Samples were prepared at 30% and 80% relative densities representing loose and dense states respectively, and triaxial tests were performed at confining pressures of 50, 100 and 200 kPa. Tests results show that fibre inclusion has a significant effect on the shear strength and dilation of sandy soil. The increase in strength is function of fibre content, relative density and confining pressure. The maximum strength improvement for both loose and dense fibre-reinforced sand is more pronounced at higher confining pressure and at higher fibre content.

KEYWORDS:

• Sand
• undrained
• triaxial tests
• polypropylene fibres
• liquefaction
• shear strength

Acknowledgements

The authors express appreciation to the staff of the Navier-Geotechnique Laboratory, Ecole des Ponts Paris Tech, for facilitating the laboratory work.

Disclosure statement

No potential conflict of interest was reported by the authors.