Soil Improvement Using Polyester Fibres

The paper deals with soil improvement using polyester fibres of length 70 mm mixed in soil SC as random reinforcement in amount of 0.5%, 1.0% and 1.5%. Improvement of soil was measured by direct shear tests, using shear box of size 0.3m x 0.3m x 0.15m. It will be shown that for tested soil, optimal amount of fibres is 1.0%, when increase of angle of internal friction was up to 6.0o (from 45.3o to 51.3o) and increase of cohesion was up to 17.5 kPa (from 0 kPa to 17.5 kPa) in comparison with soil without fibres.