Abstract
To study the effects of different factors (fiber length, fiber content and porosity) on the shear strength of fiber reinforced soil, the direct shear test of 3 levels and 3 factors was designed by response surface methodology (RSM) to explore the effects of different factors on the increment of shear strength parameters and construct polynomial regression equation of each effect factor. The test results showed that internal friction angles of fiber soil and plain soil were very close in different porosities, and increment of cohesion was changed after mixing fiber. From the analysis of variance (ANOVA), fiber content was the main factor, followed by porosity, and the fiber length and porosity had strong interaction significance; the validity of the theoretical model of fiber pull-out in soil was checked. From the test, the porosity variable influenced the effect of fiber reinforced soil cohesion, and porosity of soil should be considered in the engineering program of fiber reinforced soil.
