Effect of sample preparation method on mechanical behaviour of fibre-reinforced sand

Abstract

It is well known that the mechanical behaviour of pure sand is dependent on the internal soil structure, which can be affected by sample preparation methods. For fibre-reinforced sand (FRS), the sample preparation methods influence not only the internal structure of sand skeleton but also the distribution of fibre orientation and sand-fibre interaction. The effect of sample preparation methods on the mechanical behaviour of FRS has been investigated using comprehensive drained triaxial compression tests. The soil samples have been prepared by moist tamping (MT) and moist vibration (MV). There is a small difference in the stress-strain relationship of pure sand with different sample preparation methods. But the response of FRS is dramatically different. Under the same initial conditions of void ratio, confining pressure and fibre content, FRS prepared using the MV method shows 30–50% higher peak deviator stress and much less dilative response. A newly developed constitutive model is used to simulate the stress-strain relationship of FRS prepared using different methods.