Strength and compressibility characteristics of randomly distributed fiber-reinforced soil

Abstract

This paper presents the laboratory investigation of engineering behavior of discrete fiber-reinforced soil. Locally available <i>c</i> - Φ soil (CL) is used as medium and two types of fibers (polypropylene and coir) with a constant aspect ratio (<i>l/d</i> = 75) are used as reinforcement. Soil is compacted with standard Proctor's maximum density with low percentage of reinforcement (0 to 1% by weight of dry soil). Direct shear tests, unconfined compression tests and consolidation tests were conducted on un-reinforced as well as reinforced soil samples to investigate the strength and compressibility characteristics of fiber-reinforced soil. The test result reveals that the inclusion of fibers in soil increases both peak and residual shear strength and unconfined compressive strength of soil. From the consolidation test results it is observed that compression index as well as the coefficient of volume change decrease with increase in the fiber content. Further, the coefficient of consolidation increases with increase in fiber content. It is noticed that the optimum fiber content for achieving maximum strength is approximately 0.4% for polypropylene fibers and 0.8% for coir fibers by dry weight of the soil.