Experimental Investigation Of The Strength Of Fiber Reinforced Soil

Fiber reinforced soil is a kind of geotechnical composite material, by giving the soil to join synthetic fiber, is also called reinforced soil. At present, the fiber prospect is very broad, and used in highway, railway subgrade soil, building foundation, slope, retaining wall and the river engineering. But because fiber reinforcement mechanism is not very clear, to some extent,restrict the use and promotion of synthetic materials in engineering, therefore, an urgent needto further study on fiber reinforced.In research, to add certain percentage of polyester yarn in the loess, made of fiber reinforced loess samples. Test is mainly divided into three parts: first, the different moisture contentsthe loess in direct shear test respectively. In the optimum moisture content of18%and the different degree of compaction,carrying out direct shear test. In the different moisture content and the different fiber amount of the fiber soil in direct shear test, carrying out direct shear test.Under the optimum moisture content, in the different fiber amount and the different degree ofcompaction, carrying out direct shear test. Analyzing the relationship between cohesive force,internal friction angle and moisture content, fibre amount, degree of compaction. Summarizing stress and deformation curve as well as cohesive force and internal friction angle with moisture content, degree of compaction of loess and fiber reinforced loess.The results show that with the increasing moisture content, the cohesion and internal friction angle of loss increases at first then decreases. The cohesion is maximum when the moisture content is between16%-18%.And the internal friction angle is maximum when moisturecontent angle is18%. Adding fiber in loess can effectively improve the shear strength of loess, so as to improve the mechanical properties of soil. Having gotten out the optimal fiber qua-ntity under different moisture content. Through different degree of compaction and fiber quantity direct shear tests under the moisture content of18%, the paper has concluded the optimum degree of compaction under the different fiber quantity.