NUMERICAL SIMULATION OF RANDOMLY DISTRIBUTED FIBER REINFORCED SOIL SPECIMENS

Abstract

The rising concern for sustainable development made researchers to investigate alternatives for the synthetic forms of reinforcement. Soils reinforced with randomly distributed fibers have been a source of attraction for engineers recently because of its wide applicability and usage of natural and locally available fibers. The main advantage of fiber reinforcements is that existence of strength isotropy and the absence of potential planes of weakness which may develop parallel to the fiber orientation. Although there are many reinforcing materials and available methods, the efficiency will depend on various parameters such as tensile strength of reinforcing element, length and percentage of reinforcement added, etc. The present work throws a light on the influence of these important parameters on improvement of static and dynamic strength of the soil through numerical evaluation. A series of triaxial tests were conducted numerically in MIDAS GTS-NX software with soil samples reinforced with different fibers of 15mm, 20mm, 25mm and 30mm in length and with a fiber content of 0.5%, 1.0%, 1.5% and 2.0%. The fibers are uniformly distributed and considered as a truss element which has only tensile capacity. Nowadays, the numerical analysis has become a standard tool to investigate the geotechnical problems because of the recent advances in computational technology. The present study includes performing triaxial and cyclic triaxial tests numerically on randomly distributed fiber reinforced soil samples which is carried out by fulfilling the actual laboratory conditions. The results obtained showed that there is an improvement in the effective internal friction angle, failure deviatoric stress upon introducing the random fibers. The economical and efficient coir fiber length is 15mm to 20mm and that of fiber content is 1.5%. While further increase will lead to negligible improvement or decrease in strength. The shear modulus of the soil is also improved upon reinforcing the soil with coir fibers.