Studies on Compacted Soil with Fiber Reinforcement as a Landfill Cover System

摘要

Compacted clay soil is widely used in landfills and waste impoundments to cap new waste disposal units, and to close old waste disposal sites. The concept of reinforcing soil masses by including some kind of fiber to improve durability and strength of the soil. The present study focused on the influence of C_3H_6 (polypropylene) fiber reinforcement on compaction characteristics, strength and hydraulic conductivity. The percentage of fiber used is varied, and the test results are analyzed to search for the mix proportions that lead to an optimum soil-fiber mix. The results of this study indicate that the impact of fiber content on the result of compaction curves vary with the variation of fiber content. The optimum water content and the maximum dry density changed with addition of fiber. Initially dry density increased with increased in fiber content, reaching its peak at fiber content of 1.0%. The optimum water content varied within approximately 13% of the initial value of the natural soil. The unconfined compressive strength also increased significant with increasing fiber content. It was found that the unconfined compressive strength increased by about two and half times with the addition of 1.0% fiber content. Flexible-wall hydraulic conductivity tests were conducted to assess the hydraulic conductivity of the soil-fiber mixture. Fiber contents up to 0.8 % maintained the hydraulic conductivity within acceptable levels.