Liquefaction resistance of sand reinforced with randomly distributed polypropylene fibres

This paper presents an experimental study on the effect of randomly distributed fibres on enhancing the liquefaction resistance of sand. A series of undrained cyclic triaxial compression tests and hollow cylinder torsional shear tests were conducted on saturated sand samples with and without fibres. The influencing factors (including fibre length, fibre content and relative density), which are closely related to the liquefaction resistance of sand, were investigated. The test results indicated that samples reinforced with randomly distributed fibres can sustain many more loading cycles than can samples without fibres before liquefaction occurs; that is, the inclusion of fibres can effectively improve the liquefaction resistance of sand. The liquefaction resistance increased with increasing fibre length and fibre content. The reinforcement effect is found to be significant in both medium dense samples and loose samples. The results from triaxial tests and hollow cylinder shear tests were similar, indicating that the different loading conditions in the two types of tests will not influence the reinforcement effect of randomly distributed fibres.